Aunt Em


Aunt Em is here to try to provide answers to the questions that experts generally take for granted, leaving the

novice floundering because basic building blocks of understanding are missing. Aunt Em is always glad to be

corrected or to get extra info from smart Alecs.


More on the Vox, with an excursion into an Elf conversion to 9.5

Q. I was wondering if you might have a couple of answers relating to a VOX. While I have been playing with the Elf, I have a couple of complaints.....The focus seems extremely touchy and never really blows me away for a modern projector and I have heard that they are not the most forgiving on shrunken film, so I pulled out my VOX having finally solved my frequency issue by purchasing an equally expensive beast of a converter that weighs about 90 lbs. Basically I could carry the VOX or the converter but not both so it probably won't ever leave the house.....

1 - I just realized that when I bought it I got a speaker cord  that is severed on the end....My question is are the three  1) brown 2) blue 3) yellow/green  wires standard and if one was to try and attach a female 1/4 inch jack to the end what wires might be attached to what?
My thinking - which you may just laugh at - is to hook up a speaker jack kind of like found on most modern projectors so I can just plug in the speaker I usually use when watching films.....

2 - I am having an issue with the take up reel randomly stopping, which my assumption is just built up gunk inside not allowing the belt or belt pulley to spin appropriately....What do I need to remove first to safely remove that side plate that is covering the gears...It looks like I might have to remove the amp, the motor, and more and I just don't want to do anything that is going to come back and haunt me, since you know how limited my skills are...I know you have taken these apart often as there used to be pics with the side plate removed on your site.

Oh and I noticed there are two sets of gears controlled by a turning knob, does that mean you can run silent films on the VOX as well? I never really knew that.....Hmmmm...

A. I never cease to be amazed at the things you don’t know. The Vox was introduced first as the S, ie silent, with the amp made available later as an add-on when the sound version was introduced. Problem is, it’s a fixed 16fps for silents and as such a bit too slow.

You are right in thinking a lot of dismantling is needed to get inside to the take-up pulley. If you remove the motor, you risk damage to the wires where they enter the motor due to their great age, so I advise against.

Start with the belt itself. If it is too slack, or has stretched bits in it, or the join is long, all of these things can cause what you describe. Or if the belt is too oily.

If the take up pulley on the spool arm is stiff it can also cause problems – have you cleaned that up? Even a bent reel can cause trouble – if the width is reduced at one point it can be impossible to get a smooth take-up.

Now and only now can we consider the pulley inside the machine. There should be an internal guide which allows you to thread the belt thru and back out without problems. You could try a pipe-cleaner or even use a bit of spring belt to pull thru a narrow strip of cloth which you can hold at both ends and to and fro it to clean the pulley. However, I think your problem is much more likely to be outside.

Re Elf, it mite be that your focus problem is the lens. Short-throw lenses are notoriously difficult to get in focus all across the pic and are very easily de-focussed, and of course film focus can change too. Lenses with very low f numbers are the worst I suspect – summat to do with depth of field. You could experiment with a sleeve to hold an old B&H lens and find a slow one with a higher f. As for shrunken films, most 9.5 sound films should not yet be much shrunken, and if you are showing silents on the Elf you have left the path of wisdom. If you do not have a Specto, I can provide one.

Re speaker lead, I am not sure what you mean. What is it that is severed? Is it a lead emerging from the projector? A speaker lead for a transistor/solid state amp should have just two wires – it could be that Keith had used standard mains cable of live (brown), neutral (blue) and earth and only used two of the wires. You should have no problem doing what you suggest if, as I assume, your amp has been converted – valve amps are a bit more difficult. I use several B&H speakers permanently set up by the screen with the DIN-type speaker plugs and sockets for the cables, and all amps use one or other of these, with a short jack-to-DIN converter lead for the likes of the Elf. Basically, you just need to identify which two contacts inside the amp you need to connect to your jack socket.

Pl let us know how relevant this advice was to your needs by completing the following Customer Survey ………..

Q. First let me at least address the what I don't know part...I of course knew that the Vox came on the heels and design of the "S", but I just did not know they made it a 2-speed. I thought they simply changed the pulley and it was a single speed sound projector...Luckily I was able to deal with the belt without taking the machine apart. It definitely began seeming like the belt might be too loose, so I unhooked it and took it off, then cleaned the pulley inside and re-attached the belt but not before breaking off about half an inch. So far I have run a number of reels and it has not stopped since...

Now back to the amp......First off, how is the amp supposed to work? I am still puzzled by the whole twisty volume control (like the Home Talkie) I have yet to figure out on either machine if the amps are not working or I just don't know what I am doing....I tend to believe I am the problem, which I am sure you are on board with....... VOX specific.....I know when I open the amp cover there is some sort of crank switch that clicks and turns, but I have heard that you must have the speaker attached for the amp to even come on.....It feels like parts of it heat up, so my guess is it is on, but is it working? I never even hear speaker crackle, which causes me suspicion Perhaps if you could tell me how things are supposed to work, I might be able to see what "isn't"  and I will take some pictures of the 3 wire connection to see if you might spot an issue there........ Does anything need to plug into the pick up or is that just for some microphone thing....I have played with the optical light adjustment back and forth but never a sound, same thing with the volume twisty......................I like how gentle it seems on the film, and how even damaged film seem to pass through it without even losing a frame., but no sound...

As for the Elf, I have had better luck, and actually found an original Eiki 25mm lens that improves the focus considerably, now I need to find an original 38mm Eiki lens and I will be set.

PS.  Is the sound on 9.5 ever good? Everything I have just bounces between passable and almost unintelligible in the same reel.

A. Glad you got the take-up working – no need to thank me for the advice – oh, you didn’t.

1. Getting an original Vox amp working is far beyond my ken.

2. I have no idea what you mean by a crank switch.

3. The so-called volume control simply cuts off part of the light bounced from the sound telescope via the mirror. Less light = less sound. Trouble is it also affects the quality.

4. An original Vox amp was, I believe, wired so that the speaker plug incorporated a short across two pins which completed the circuit for the amp power supply – in effect an on-off switch. I am not sure, but it is quite possible that the valve heaters were on as soon as power was connected to the projector, but not the amp circuits themselves. And who knows what changes may have been made over the years? It’s no use trying to run the amp; it is almost certain that the output capacitors have long faded and you will do more harm by running the amp before these are sorted. But there is so much that can be wrong with a really old amp. There is incidentally some stuff on amps under care and repair on my website.

5. Pick-up is just for a non-synch record deck.

6. Re Elf focus, even with an original Elf lens there can be problems if the little rubber bit on the focus wheel shaft inside the lens barrel is perished – it could make the lens just a tad loose and so harder to keep in focus.

What I would strongly recommend is leaving the amp alone for now, and not plugging in the speaker. Fit a diode/cell in place of the mirror under the sound telescope, lead the wire away via the arm supporting the sound drum and plug it into the microphone input of a 16mm projector amp – I used to use an old-style B&H for this (now I use a transistor replacement designed for one of the same machines, but as a stand –alone). This way you get the full benefit of an amp and speaker specifically designed for cine. Non-cine amps will not give you the best results from 9.5 optical which can, at its best, rival 16mm.

There are many other things in the long chain of things involved in producing sound, eg the stability and smoothness of the sound drum in its rather basic bearings, the free-running of the roller that holds the film onto the drum (ensuring also the groove it runs in is clean), the cleanliness of the telescope optics and the width of its internal  slit, the exact position of the lamp (if you are not using original Vox lamps), the presence or absence of the little cover inside the lamphouse that stops extraneous light getting down onto the film and the cell/mirror and etc. A lot of this is in the piece on my website under 9.5 sound called In Search of the Lost Chord.

I am happy to field supplementaries, but pl remember that pix can help – I would especially like to see inside that amp cover.

Q. Picked up a CAMPRO recently. Just interested in putting it on display beside the MIDAS but, while in the case of the MIDAS I obtained an Owners Manual etc., for this CAMPRO I have nothing! If you have anything on it, would appreciate your input or if you can refer me to another source. I'd like to know what cartridge/magazine/charger was used; what voltage was used to the lamp and how the unit was set up as a projector?

(Before I even had a chance to reply, a further email followed..)

Q. Sorry, sorry. Should have read your extensive website first! You've probably answered all of my questions.Have now just downloaded a hard copy to study, so I'll re-phrase my request.......if you have any 'new data' not yet published, I'd appreciate that,otherwise, I'll read all and if I have questions will come back to you. 

  A. What can I say? Actually, I find myself a bit like a gramophone record sometimes, repeatedly telling people "There's a lot of info AND PICTURES! on my website."'

Q. You know what ?, I think you need an INDEX at the start of your comprehensive website for stupid people like me (!) so that the contents will POP OUT AT US before we start asking 'silly questions'. Sorry again.

A. There is a Projector Index and a Contents page, nestling next to each other at the top of the more traditional list of main sections on the Home Page. I think I should take your spade away before you dig yourself any deeper .
Q. You're being cruel now! (I know I deserve it). My problem has been that every time I open your website I JUMP STRAIGHT INTO 'WHAT'S NEW'.......not a bad thing, but I seem to forget the vast amount of material that is already embedded in the site after years of input by your good self. I will try harder in the future before you dismiss me out of the Class! Sorry again. Now get back to work with your important projects while I play around with my 'older version' CAMPRO.

Q. All read, understood and the little CAMPRO is alive and well and up and running, even the lamp illuminates brightly! Can't really say if I'll ever put it to use but it was fun getting it to operate. One question, when you have the time, did you ever source the little 'Projector Attachment' or establish what in fact it was ? Was it ONLY for the older version or for MKI and MKII

A. At last! You have found a small hole in my defences! No, I never found out anything about the attachment. Mind you, I never tried. A task worthy of your attention, perhaps? If you thought cruel before, how about this? I thought our recent exchange would make a splendid addition to Aunt Em's column. How much is it worth to anonymise it?


Q. At some point I will need to pick up a 17,5 sound projector that won't destroy the films. I actually have a Natan, which I am told is the French version of the Home Talkie, but you have basically made me terrified to ever run film through it, for reasons you explained elsewhere. Because of such I have been hoping to acquire one of the PathRural, or Super Rurals that came later and appear to be much gentler on the films....For some reason I was under the impression you had a few of these do you not? Perhaps I just assume you have a few of everything that you are hoarding away to taunt people like me when we start longing for something.

A. As for care of films and risk of damage using a Home Talkie, I have made various transfers to Video of 17.5 filmsincl Christus, Destiny, Sleepless Nights, 3 Men in a Boat and The Avenger (actually a now sadly deceased friend did the recording). All these used the Home talkie. And Lorna Doone. So, basically, the HT is fine as long as two conditions are met. First, the film must be in full repair with no uncorrected faults or damage and second, you have to thread it right. The problem is that both feed and take-up use not only the same sprocket but also the same arm with rollers for holding the film onto said sprocket. It is very easy to allow the film to slip a bit under the sprocket (ie for the pre-gate loop) when threading over the top (ie for the post-gate-and-sound-head loop.) This can mean the film is not properly engaged with the sprocket teeth and so won't be fed through. As there is no pre-gate loop to speak of, damage is instant if a problem occurs. Bear in mind, tho', that the Talkie had a few years of active commercial life and that, despite abuse by many loonies in the intervening period, a great many films still survive.

However, let me give you the full story. My holdings of 17.5 machines are as follows.

aunt-m aunt-m

2 x Rural silent machines, known as the Rex in the UK. They use the Vox lamp. They also have only 500' spool arms,tho' the 1000' - 1600' arms from sound machines also fit.

aunt-m5 x Rural Sonore machines, sadly all converted to 16mm, and one being a spares machine only. I have one of them (pictured) up and running as a 16mm projector. It is just a Rural silent with an extra "layer" added, carrying the sound unit and the capacitor for the constant speed motor. Two of them need a lot of work.



5 x Home Talkie machines, two of which are promised to other people. I also have two very battered Natan mechanisms - no base.

aunt-m2 x Super Rural machines. These are both 17.5. One was much mutilated by its last owner, but nowworks. The second is in bits.

aunt-m1 x 16mm Type 45 (?), which is a Super Rural on a different base and with a separate amplifier, only ever made in 16mm.

In addition to these, I have a much-modified Gebescope Model A converted to 17.5 by the late John Cunningham. It has the advantage of an intermittent sprocket instead of a claw. And finally, a GB L516 converted to 16mm, also by John.

Deciding on which projector is a right can of worms. The only machine found, and that rarely, in the UK is the Home Talkie. The Rex was hardly ever advertised and is vanishingly rare. The Rural Sonore was never introduced here. The Super Rural was advertised, but what with war and the end of 17.5 not long before, it is again vanishingly rare. My second machine (and the Type 45) definitely came from France and the other did also, I believe. I have never come across a machine actually sold officially in the UK.

In my view, the Rural and Rural Sonore are the best. They have a straight film path of conventional type, so there are adequate-size loops. I have doubts about certain aspects of the sound set-up, because of the risk of scratching on the separate drum where the sound is read, the flywheel appearing rather later in the film path. However, I have never seen a 17.5 Rural Sonore.

I think the Rural and the Sonore are brilliant pieces of design, very well suited to their expected working environment which was essentially commercial and not domestic, and to the way Pathé provided services to users. The main base is solid and the machine is in large measure of modular construction. The lamp and motor resistance and controls of the Rural are all on a single unit that can be easily removed without any special skill or tool. The lamphouse is a unit, which has a separate plug into the control unit, as does the motor, which can be removed by undoing a single knob. And the ease with which the machine lent itself to conversion to sound is, I think, a tribute to the original design. These machines were ideal for the rough and tumble of transport and ad hoc set-up in various halls and other venues, but usable by almost anyone. The 500' spool arms on the original Rural are an interesting feature. Unless one had two machines, which may have been beyond the means of many, particularly as it might well need a second operator, too. I nonetheless regarded a film show with regular interruptions as something decidedly peculiar, until it was pointed out to me that early film shows often did the same and, of course, today we happily(?) cope with advertising breaks.

I have thought long and hard about converting my 16mm Rural Sonores back to 17.5mm. The sprockets are straightforward enough, but the sound presents more problems and the claw and cam are a really major issue. I have had a replacement up-and-down cam made which will, I hope, suit 17.5mm. It cost £100 some years ago.

aunt-m aunt-m

These two pix show the cam/shutter assembly. In the left pic, top is the up-and-down cam, next the in-and-out cam and bottom is the shutter. The two cams are basically just larger versions of those in the Baby projector. It seems to me that duplicating the in-and-out cam with the necessary modifications to suit 17.5 is a project I can't even understand, let alone complete. You can't use the original as the 17.5 claw is about 10mm to the left of the 16mm one; it would not ride on the 16mm in and out cam. I have come to the conclusion that the only sensible way forward is to run 17.5 back to front and use a mirror or prism to reverse the image. This greatly simplifies both the cam problem and the sound side. You still have to have the up-and-down cam made, and sprockets (I happened to have some) and guide rollers etc, but it seems to me more achievable - as long as the greater throw of the up-and-down cam does not make the claw lift off the in-and-out cam......

I I also have a problem with the Super Rural - see the next two pix.

aunt-m aunt-m

Not only is the top loop very tight, but the lower loop has very little space to operate in and, unless constrained in some way, the loop has a tendency to flip forward onto the sprocket and the film as it runs up tothe sprocket after leaving the sound head.

In pic 2, there appears to be a pin to stop this, which rather tends to undermine the whole purpose of a loop, by in effect making it much shorter. However, this is not all. Try as I may, I cannot get the loop long enough to give a sound/picture separation any bigger than 19/20 frames, ie like 35mm. On a Home Talkie, I cannot get below 26 frames. I can't see what I'm doing wrong and I must be wrong 'cos I can't imagine this being deliberate. Surely 7/24ths of a second out of sync would be noticeable? I have acquired an electronic delay unit which would deal with this, but these were not available back in 1938! I wonder if there would be an issue with 16....


Q. I'm a novice camera collector in Brazil. I can't find much information in Brazil about collecting; have you any information about cleaning and restoration of old 8mm cine cameras? Could you recommend some book or internet address?

A. The big problem is that very little old cine equipment except some 35mm and a few rare machines have ever attracted much general interest or the sort of value associated with antiques. It's always been a specialist area; in fact, there are hardly any books at all about cine equipment and even fewer about cameras.  What little I know is on my website, . Under Miscellany, you will find a page for books, and there are just a few on cameras. In addition to his book on projectors, Jurgen Lossau did one on cameras - you would have to look for a second-hand copy.  The only other source I can suggest is - they provide copies of old instruction books and manuals, but are expensive. And there may well not be anything on the camera you are interested in. Otherwise, it's searching the internet - there are lots of sites in the US that cover all sorts of things and you may find something there.

A word of warning. If you are dealing with old wind-up/clockwork cameras, be very careful. The spring mechanisms are immensely powerful and could easily take an eye out if they undo suddenly.  If you can give me any better idea about what you are trying to do, I will try to help further.

Q. Thanks a lot for your advice on springs. I just started collecting 8mm and 9.5 mm cameras and projectors. Actually, I don't intend to fix damaged cameras, but only clean them up, and put some life back in the leather.  What do you recommend?


Tricky, as I doubt the marketeers supply the same products to our different markets. A good start is WD40, Plus Gas is a similar product. It's designed for loosening stuck nuts and bolts etc, but is a good general lubricant. You need to be very careful about using cleaners or solvents. Some solvents can actually take off the surface finish and change the appearance. I have found that Turpentine/white spirit (stuff used as thinners and brush cleaner for household paint etc) can leave the surface with a white deposit/sheen that is hard to remove. I suggest one of the foaming, citrus-based aerosol cleaners (from electrical component shops as well as supermarkets etc). Whatever you use, try a bit on an inconspicuous area first (or maybe a camera that is too damaged), and let it dry. Water and hard work, with plenty of rags, can be very effective. Do not use abrasive cleaners, even Cif,or ones containing bleach.
I would advise against the use of metal polish except for plated parts (chrome/ nickel) or bare metal. Many car polishes, for example, leave a white residue that you polish off; this works only if your surface is completely smooth with no tricky corners and angles. Some cameras and projectors have a rough surface finish, wrinkled or crackle finish we call it, which you can never get the white out of.
In the final analysis, a very very thin application of paint may help, if you can match the colour. It has to be thin, to avoid filling in any wrinkle finish. I have often used Hammerite satin-finish black, eg on the Peerless/Triplico on my website.Touching up individual chips where paint has been lost can easily look tatty, as it is impossible to avoid paint spreading outside the intended area, and it shows. Masking tape can be used to mask off areas before spray-painting, or you can apply the thinned paint with a brush, working it into the wrinkles and ensuring you don't mess up the original surface.
For leather etc I have used a range of products that includes a thick, honey-like cleaner/moisturiser, and then separate finishers for leather and artificial materials. The leather one I use actually adds a leather smell. The company is called Gliptone and the products are called Liquid Leather, but I suspect it may be limited to the UK. I found them from a company selling materials and equipment forautomobile restoration/customising - quite a few of their products have proved useful for my purposes. I dare say you will find a similar company in Brazil!


Q. Dear Aunt Em,

The 28mm Victor I recently acquired is extremely mucked up and I have been cleaning it, but wondered what do you use as a degreaser, and how have you handled rust in the past? The sprockets are fairly rusted.


De- greaser is not important - just get most off by hand, then maybe a bit of WD40. Lots of rags and elbow grease. There are some things like turpentine/white spirit that do not do well with paintwork and can leave a white haze. Some stuff can also affect paint, eg the finish on the Bolex DA seems to be some sort of lacquer that you can all too easily take off. Like they say on the packet, test on a small inconspicuous area first!

Rust. It all depends. Light rust can be cleaned up with a good metal polish - I use a non-abrasive one designed for chrome, brass etc for most purposes. Needs plenty of elbow grease. You can achieve an acceptable finish even if the nickel or whatever is worn away in places. For more serious rust, there are various proprietary de-rusting fluids in which you can steep parts but be warned. They are not all equally good, and if you leave things in too long they can actually partially dissolve, even tho' they don't tell you this. Or get a nasty, dirty-looking result. Use with care and polish afterwards.

For painted parts, esp black, there are rust converters sold for use on classic cars which often give a black finish. Then you can sand off. Sanding is the other recourse for really bad stuff, usually by hand but sometimes machines can help. I have a foam plastic drum with a sanding belt on the outside. I stick the drill in a vice (need special attachment to do this really) then hold stuff against the belt. There are many pitfalls. If you don't grip firmly, and approach the drum from the right direction, parts can be snatched from your hand, thrown across the room and damaged (or you could be). With machines, you can easily take off too much - I use a very old sanding belt that can't do too much at once! Also stuff gets hot - wear gloves and have some water near to dip the part.

There are also various polishing devices which can help when you reach the appropriate stage - usually for drill fixing, eg sisal and cotton mops, with various unguents to help. I have found that with round parts it is sometimes easier to put the part in the drill (usually on a spindle) and apply the polishing mop by hand. In the extreme, you can go mad and get the parts re-chromed The problem with chrome or nickel is that it is a wafer-thin layer which just reproduces all the faults of the original - so, if the original is pitted, you get a pitted finish with the new chrome (or nickel, which was often used on older stuff - be careful not to get the modern over-bright nickel - stick with the original more lustred finish)

And with most stuff, once you have got serious rust pitting, it's impossible to remove without destroying the part. One of the worst I have had was on the Triplico/Peerless; it don't look too bad in pix but the pitting is still there.

Another approach with painted parts is Hammerite - don't need to remove all the rust and a good thick layer can smooth the surface a bit. Or you can try filler - car stuff is probably too soft, but there are all sorts of proprietary stuff you can use like Milliput. This is what I used in Back From The Bodge.


Q. Dear Aunt Em
I read your page about restoring an H with interest. I've just acquired one and mechanically it seems OK, even with a spare bulb, but the electrics are not fit to have in the house. I don't do resistors wrapped round flaking  asbestos! So - the plan is to rebuild the electrics completely. The lamp, lampholder and low-voltage transformer are available - I'll be going for a 12v qi bulb.
But the motor? If it's a 240v unit all will be well but otherwise I'll need to get a transformer and possibly some sort of variable speed control as I intend ditch all the asbestos. Again that shouldn't be a problem, and I'm  not too fussy about retaining exact original features - the object is to end up with a serviceable and SAFE machine.

For example I won't try threading the lamp cables through the motor which, reading your commentary, seems best  left alone!!! The starting point would be getting some details about the motor in terms of voltage and current consumption. It seems to me it might be a 120v unit to judge by the enormous amount of resistance wire in the  base - although I haven't checked how much is actually in circuit at normal mains settings yet. The whole machine was obviously intended to be transformerless - a scary resistance unit is included for the lamp volts. This would be to make it capable of running on DC (the mains plug is a lampholder bayonet plug and I recall that certainly where I live some buildings still had DC lighting in the 1960s). 
Any ideas about motor volts, and any tips?

A. I can appreciate your concern about asbestos, tho' I think collectors would never live so long if there was a universal and serious problem. Nor am I wholly convinced that the "former" on which a resistance is bound is  necessarily asbestos - it could be the sort of high-temperature ceramic they used to use in coke ovens etc.  Not that it matters.  What an H should have is an 80v 100w lamp, fed from a transformer. I have not come across one where the lamp is fed from a resistance, tho' I suppose they may well have made one precisely because of the DC problem.

I would like to see some pix if possible of yours in case it's a variant I've not come across.  But now you ask, I'm not wholly sure what the motor voltage is; in fact, I don't think I've ever actively thought about it. There are at least two different versions of the H wiring; one has a cylindrical resistance marked  with voltages 190/200 to 250, as per the outside. The other just has a tranny, which presumably does whatever it is the resistance does but I know not whether this affects the motor.  Considering it logically, motors were often multi-voltage and could be over-volted without immediate problems.

Rumour has it the Son motor was wound for 160v but over-volted to 240 (cost-saving idea - a bad one). And, having  consulted my own website, something I find myself doing with increasing frequency, I note there is a pic of an H conversion I did using a switched mode tranny as per low voltage lighting, so there is no possibility of any  feed other than 240 to the motor. Having settled that, I think a standard mains lighting dimmer switch (old type rather than newest ones which are for energy saving lamps) would handle the speed control just fine. The only
caveat is that if you do have an unusual resistance-fed machine, all bets are off.

Anyway, do send me some pix and let me know how you go on. Incidentally, have you considered a Specto rather than an H? It's a much better machine, with scope for more powerful lighting and bigger spool capacity. As for any other tips, there is probably more info on the website now than remains in my head. Just be careful if you do dismantle the motor not to stretch those connections to the brushes. 
The problem with the wiring thru the motor is really one of extreme fiddliness, rather than danger as a direct result of this design. The danger arises because the insulation on the wires rots, leaving the machine open to short-circuits or live bits wot did not ought to be live. Old age. If these are replaced, there should be no problem.

Q. I got your details from your website and thought you might be able to help me out with a technical question. I have two Bell & Howell model 601 amplifiers, Part 202000 and was hoping you could advise on the power supply connection. I note it's 110v supply but am not sure how to connect the 4 pin connector. I've attached a couple of photos to show the amplifier complete and the connection in question. Any help you could provide, or guidance on where to find out more, would be very gratefully received.

A. B&H were really a pain with these 4-pin plugs, tho' there were far from alone in this dog-in-a-manger attitude. Lamps too, of course. (Have lots of these if you need any). There are of course only 3 connections, live, neutral and earth, but they often use the fourth pin to provide a feed to a different part of the machine, so you can't necessarily tell just by looking at the inside of the socket on the apparatus.

I can never remember this stuff, but I worked it out once, albeit for a later machine and, miraculously, made a note!

B&H Receptacle


RED l 16 14 l GREEN

l O__ l______________ Locating Pin

YELLOW l 15 13 l BLACK


This shows what I found in a B&H643; colours relate to wires connecting to the back of the pins, ie from inside the machine. The corresponding sockets of a B&H lead with a moulded-on Jones plug (presumably therefore original) were wired as follows:-

15 & 16 Live

14 Negative

13 Earth.

I cannot guarantee yours will be the same, so please be careful! I don't have any paperwork earlier than a service manual for a 625. There are two addresses on my Links page under Miscellany which may help:- A (mainly 16mm) website, Inter alia, he has attempted a list of all Bell and Howell projector models. has manuals and stuff, tho' mainly American and modern.

Q. Many thanks indeed for your help with this - and such a prompt response! Really appreciated.
One thing that maybe different on the mains plug that I'm dealing with - I don't recognise the locating pin. I don't have the amp with me at the moment to have a close look, but don't remember seeing one. On this basis, do I treat pins 16 and 14 as top left and top right respectively, when viewing the chassis plug on the amp?
A. Bugger. What you have is the socket for the small plug on one leg of the "Y" lead, the other leg having the bigger plug for the main projector supply. This I have not looked into, so will go find a "Y" lead - sure I have one somewhere - and run the meter thru it.
LATER. I've rummaged thru my bin of old leads. This sort of stuff does my head in, trying to figure stuff out on both plugs and sockets, so I hope you can do better than me. These rough sketches show what I have found. The problem is, one needs to go inside a B&H tranny to see exactly what is coming out to which wire. Can't do that this week, I fear - let me know later if you still need me to do that.

aunt-m aunt-m

17.5 Home Talkie/PathNatan

(This is an edited version of a longer and more diffuse exchange)

Q. I recently acquired a 17.5 PathNatan (much the same as the UK Home Talkie). I threaded it up and hand cranked it to watch and see what everything does, and where everything goes, etc. I did this for a while so I felt confident and turned it on. Everything ran smoothly, but YIKES! That thing is moving so fast it scared the bejaybbers out of me. Even if it was running perfectly, it looks like one of the scariest projectors ever, with the slightly offset path through the gate, and the frightening GEM/SON wrap around the body of the machine, and then the sharp turn straight up to the take up, and the crazy sound slide thingy that looks like it scrapes the film? Or does it look scarier than it is?

Now I find it is losing the loops almost as soon as I turn it on. I am perplexed, as I feel like I am threading the machine correctly. I can turn it by hand all day and it runs beautifully, but as soon as I start the motor it almost immediately loses the bottom loop, and then somewhat quickly loses the top. I try to see where things are going crazy and the closest thing I can see is the gate area seems to have more movement than I have seen on other projectors. What I mean by this is the back plate of the gate that is attached to the lamp housing, seems to almost be bouncing around. Does this seem normal?

I am first thinking about replacing the screw just beneath the gate area with one that I can screw in with a roller on it, so it won't lose the bottom loop, especially since that is the harder of the 2 to watch easily (the top one I can see as it is disappearing).

I don't see how a roller stops it losing the loop. All it will do, surely, is to in effect make the loop smaller, with less slack before it catches on something - unless you have in mind an auto loop former? -so that it gets lost even quicker?  

The correct way is to get the film and projector in good order and thread it correctly. Don't forget that these machines managed to work OK for some years in the hands of God knows who - they will work if treated properly. 

With the Natan/Home Talkie, the threading around the sprocket is critical. You put the "top" (in this case lower) loop in place, but then you have to open the same set of rollers again to thread the "bottom" (higher) loop thru. It's easy for the "top" loop to slip out and as there is no loop worth speaking off, huge damage occurs at once. However, I have found that so long as the film is in perfect repair, it will go thru fine if you get the threading right. But don't trust it an inch - watch the machine, not the picture!  

There are details somewhere on Cinerdistan of a device I developed for providing movement of the sound chute during projection - normally you can only adjust it when there is no film in the chute. I did this 'cosI had quite a problem with a wandering sound track on Lorna Doone - kept getting that snoring noise from time to time as something other than the track got scanned, with no way to correct it. Despite looking scary, the chute does not seem to do any damage; note that the instruction book makes clear the chute must be fully closed with the film bowed.

The back gate should be fixed to the projector by 2 small screws, one visible above the gate, the other you need to take the lens off to see - easiest to adjust this one with the screwdriver thru the nozzle at the front of the lens housing. If either of these is loose, it could affect the gate. Make sure they are tight, but with care - not a lot of thread to play with. The screws have to be v. short so as not to protrudethru the gate - may need a washer or 2 under the head. There is a bit of adjustment for framing. Of course, if someone has been careless in the past and stripped either or both the threads, we have a problem of a different order.

Q. I did just notice something that may be part of the problem. The bottom roller on the one sprocket wheel does not seem to keep the film tight against anything. I noticed that even with everything all threaded up I was able to slip and slide the film that is entering the gate as if it were not even one the sprockets, perhaps it is simply slipping off the sprockets. I looked at your pictures, and while yours does not seem to be completely pressed up against the sprocket wheel, I am guessing there is just enough space so that when the film is there it is touching. I checked the hole the pivot arm clicks into and it does not seem to be worn at all, but there definitely seems to be too much play between the sprocket wheel and the rollers. I've included some pix.

aunt-m aunt-m aunt-m

I think I have at least figured out why the top loop is being lost. After much watching, hand cranking, and very brief motor running it appears that the bottom loop is in fact the one going away, then because of the slip the top starts vanishing. My best guess is that the film must be just shrunken enough so as to not reach the sprocket causing it to slip before heading up to the take up reel. I am guessing that it has about a total of 2 - 3 sprockets worth of play before the loop is entirely eliminated, and once it misses that first sprocket, it is done for. My question then becomes is there a way to avoid this or compensate somehow? It seems to have something to do with the speed as well, because I can hand crank the same section and it won't slip. Is it possible that when things are moving along fast the rollers are not making as tight a connection? Maddening.

A. OK, leave us look at this logically. If you are losing the bottom loop, this means one of two things:-

1) The film is entering the loop slower than it is leaving, so we have a gate/top sprocket issue;

2) The film is leaving the bottom loop faster than it is coming in, so its a bottom sprocket /take-up problem. 

Stans Treason, dunnit? 

I suspect2) so let's start there. 

There are three possible projector problems I can think of (at the moment I am leaving out shrunken film cos I have never had a problem):-

a) sprocket retainer roller not close enough to sprocket or slack and can move up and down in relation to the sprocket, or misaligned laterally in relation to the sprocket;

b) belt too tight;

c) clutch tension too great. 

In b) & c), the problem may be compounded by a), or in a severe case may even just pull the film thru despite the rollers being positioned correctly.

aunt-mI have in front of me, even as we speak, two patterns of take-up clutch (see pic). The spring one is obvious. The second may have a problem with old, solidified lubricant, so just needs taking apart and complete cleaning. I can't recall, but there may be springs under the outer big washer. Belt tension I assume you can deal with.

A bent spool scraping the side of the film intermittently might contribute to the problem. 

Returning to a), the retaining rollers, any problem here can affect the lower loop at either end. The projectors front main casting, by which I mean the one to which the rollers are fixed, is pretty soft metal and I have found that the holes may enlarge, not least the two holes relevant here, ie those for the pivot and the spring-loaded locating pin. I have seen machines with these sleeved up to make up for excess wear. I think on one machine I had to sleeve up AND make a new pivot bolt with a different thread as the old one was no longer fittable. Obviously, if the locating pin hole has enlarged, the rollers will not be held correctly to the sprocket, so when the machine picks up speed........... 

Turning to 1), the gate/sprocket issue, part of this we have already covered above. However, the adjustment of the gate is important. There is usually some small scope for lateral adjustment of the front, fixed gate, as well as vertical for framing. It's important to ensure the sprung gate can move freely when in the closed position. Shut the gate, then push with your finger at the top and bottom, against the gate springs; there should be no grating or sticking against the sides of the fixed portion. As mentioned, the fixed gate may have a bit of adjustment, tho' care is needed to avoid getting the film in a position where the claw does not enter the film cleanly. The lamphouse pivot can also come into play - thin washers either side of the pivot lug at the bottom of the lamphouse may have a role.

aunt-mMoreover, looking at yore pic (see attached), it seems to me the surfaces pointed out in green should be in contact with those marked red, separated by at most a film-and-a-bit-for-splices-maybe thickness AND unable to move from there. You say the locating pin is firm? Is the pivot firm? Just where is the slack between rollers and sprocket coming from? 

Hopefully the foregoing will give you scope to identify the exact nature of the problem. Then we have to move on to a solution.

Eumig Mark S

Q. Just been having a very enjoyable browse around your site, which I came across as a result of searching for info on a Eumig Mark S projector. I haven't yet received the machine, but Im anticipating the need to overhaul it before use.

I was wondering therefore if you might have a circuit diagram for the amplifier that you might be kind enough to let me have a copy of. I have a few years under the belt with steam radio restoration so I don't anticipate too many problems, but its helpful to have a map before you set off!

Strangely, the need for a Standard 8 sound machine originated with a print of The Telegoons I was lucky enough to find; something I'm quite looking forward to seeing!

A. You are hereby sentenced to 1 week of corrective reading of CINERDISTAN.

aunt-mBecause, in the 8mm section, under Various 8, you will find a full instruction book for a Mark S, including a circuit diagram. I have attached another from a different booklet in case there is any substantive difference.

The biggest single problem with the Eumigs is getting them up to speed.3 major elements:-

1) The motor/fan unit tilts and the bearings rot. Details of the problem will be found as above.

2) The tilting is what actually engages the mech, by bringing a knob on the end of the motor shaft into contact with a

rubber wheel. Time is not kind to this mech and it frequently runs slow; one way forward is to slightly roughen the

rubber to give the knob a better grip.

3) The grease they used originally has gone solid and makes the whole drive train stiff, including up the spool arms.

Ideally, it all needs removing and new lubricant adding.

Enuff to keep you going?

Q. M'lud, I plead reading the website during my lunch break. In further mitigation, perhaps it was your mention of plastic and transistors in the intro to the manual that threw me, knowing I had a valve one... ;)

The diagram's great thanks. Everything clicks into automatic: first thought was "replace C21, 10nF output valve grid feed"!

You may like to inform your readership who may wish to work from these diagrams (unless you already have and I've missed that also) that the voltage readings quoted would have been measured with an Avo 7 or 8 meter. Measuring with a digital meter (with a far greater input resistance) will tend to report higher values than those quoted on the sheets, as they don't load the circuit you're measuring so much.

Thanks for the advice also on the dried lubricants. My photographic nerdity concerns restoring/repairing old still and cine cameras and the lubricant problem is a continual bugbear - particularly, I've found, with Russian equipment and Agfa focussing helicals!

I'll tell you something about my experiences with your favourite Eumig P8 which may amuse, though at the time I found little to laugh about. I found one of the Phonomatic variety some 25 years ago, with all parts still sealed in the plastic bags. Attached a mains plug and gave it a go. Found out the hard way the projector casing was at mains potential. The cause of this was the mains cable: remember I unsealed the package myself. The plug on the projector end had been wired with the earth and live reversed (perhaps the artisan in question was red/green colour-blind). So I never liked them since - and never did work out why they took up film the 'wrong way'!

Later. Q. Just to close this one out, a note to say many thanks for the info you supplied and posted on your website. Ive taken delivery of the Mark S and its immaculate everything free running and undamaged with the exception of the motor pivots, of which there is no trace remaining! I'll be following your advice to manufacture same.

A. Nice to be appreciated.


(This is distilled from a much longer exchange).


I have a Specto 9.5mm film projector and a 16mm one; the problem I have is on the dual machine the double claw goes left and right but has stopped going up and down. Do I need to be into the gearbox to fix this problem, if so do you know the procedure to get into the gears.


I've come across Specto's running backwards, but not your problem. There araunt-me two cams (see pic). The one nearest the lamphouse you can't see as it's behind a retaining plate; this is the up and down cam. The other, nearest the lens, is the to and fro. The problem may be as simple as the round cam assembly being loose on the shaft. There are usually one or two little grub screws that hold it to the shaft. You can see the screw hole for one of them in the pic.They may well need an Allen key rather than a screwdriver - take care to use the right size or you may damage the heads. It needs to be in synch with the to and fro movement. It sounds unlikely in principle that the gearbox would go at all if there was something wrong with one of the drive shafts. I assume you've kept the gearbox oiled. If you feel you need to go into the gearbox, I assume you have viewed the Specto pix in the multi-gauge section of my site; I don't know of any written material. Basically, you have to remove all the chain drive and sprockets from the back, and the inching knob, to remove the cover plate. Please make a point of telling me how you go on - I'd like to know what's wrong!


On looking closer with magnifying glass, I noticed the shaft is moving as I turn the cam manually. I put a small dot on the shaft that holds cam, and noticed it rotating the same as the cam. I got into the gearbox and found that the gear that drives the cam was running loose on the shaft. There is a flat on the shaft to help secure it.Is it usual for the claw to have a tapping noise when projecting a film? The Specto 16mm instruction book it says the gears are worked with oil only, and the dual is a mixture of grease and oil. Could you by any chance describe a ghostly image and what causes it?


Oh well, Ive now learned something new re Specto gearboxes. (We also discovered in the course of correspondence that there are at least two different sizes bore and front-to-back dimension of chain sprocket in the drive train).

Interesting about the lubrication - I can't be bothered and use oil and sometimes a bit of spray grease, which is nice and thin. In the old days, I used Vaseline on claws/cams.  

Ghosting is most easily seen on titles, and takes the form of streaks of semi-transparent stuff below or above the letters. It is caused by the shutter being incorrectly set, presumably as a result of the stuff you've had to do with the mech. It's fairly easy to fix on a Specto; the shutter is held onto a shaft by the usual grub screw and will turn freely once released. You then turn the machine over using the inching knob, with the lens holder open so you can see what the claw is doing. You need for the big blade of the shutter to be juuuust about covering the gate aperture when the claw starts the down stoke, and for it still to be covering the aperture until the claw stops going down. (The small blade is called a flicker blade and is just to reduce flicker. It won't cover the aperture enough to stop streaking.) That way, none of the movement of the film can be seen on screen, which is what causes the streaking.

You need to check at the other end of the claw stroke, to make sure the aperture is still covered when the claw stops moving down. Only just again - the shutter blocks light so to maximise light on the screen the main blade is kept as small as possible, so it has to be adjusted just right. You may have to compromise a bit to get the best balance of covering the aperture at each end of the claw stroke. Then you just tighten up the shutter and it should be OK. You may need to do a bit of trial and error, tho. Watch the fore and aft alignment of the shutter - you don't want it catching the inside of the lamphouse as it turns. Really a silent projector needs three blades to avoid flicker but manufacturers were always trying to find ways round it. Trouble is, as lightoutput rose, any flicker became more noticeable. Nonetheless, the Specto is pretty good; I believe they avoided problems by a fast shutter rotation rate.

You often get a clicking/tapping noise with film - it varies from film to film. Only experience will tell you if it's actually a problem - make sure the film isn't being damaged. Best way to do this is to make up a short loop of film and let it run thru 50 times and then see if it's getting scratched or if the sprockets are getting "picked" or strained.

Q. Another Specto question. Other than a mistimed shutter can you think of what may cause a ghosting to appear on mainly intertitles. Is this something that could be caused by the claw?

A. I suspect ghosting is there on pix too, it's just more noticeable on titles. I can't think of a cause other than shutter/claw timing, tho' I am not sure of how this is adjusted on a Specto - must look sometime! Part of the problem may be the old story of how to get enough light to the screen. Specto used the "grasshopper" type claw mech, where the claw makes two strokes per frame, but only engages the film on one. This means a faster claw action and so a faster pulldown and so more light thru to screen.
This however is achieved by reducing the size of the shutter blades, and sometimes they went a bit too far. Somewhere buried in the Premier Pathescope 28mm instructions (see website) is a reference that suggests the intermittent (already slower than a claw, anyway) actually starts to move before the shutter fully obscures the image and vice versa after, and even claims this as a good thing!
I suspect, too, that ghosting , as with flicker, becomes more noticeable as you increase the light output and change to the whiter light of tungsten halogen.
All of that said, you should not get ghosting with a Specto and it seems to need some adjustment. If all else fails, you could even try making the shutter blades fractionally bigger. Another thought that has just come to me is whether, with non-optical framing, prints that require maximum adjustment of the framing one way or the other might actually throw the claw/shutter alignment fractionally out of whack. This sort of thing makes my brain hurt; it will take me some time to think this one thru and figure it out.

Pathé Vox

Q. As well as an active filmmaker, I am a passionate collector of movie machines and films. Although I don't have the amounts you have, I have
a fair amount of "stuff" in 35mm, 28mm, 9.5mm, 8mm and super-8mm. I have never come across 17.5,other than in editing sound, (magnetic
sound that is), for 35mm films (yes, every time I can, I edit my work on my 35mm moviola) and often times one uses 35mm full coat magnetic
film split in two, for the sake of economy.

I recently acquired a Pathé Vox and since I have been having a lot of trouble to find documentation about it, and having stumbled across
your enlightening web page, I wonder if you could clarify some doubts I have about the machine.

First: how can I tell if my machine is a Type "V" or a Type "S"? Second: how can I find a lamp for the machine? I would rather stick to the original, which I believe is a 15v 200w for the Type "S" or a 15v 400W for the type "V", but I gather from your writing that this may be difficult or impractical. Third: which leads me to finding out if the adaptation you made for a modern lamp, keeping the original projector's base, is successful and maybe available or reproducible? Fourth: my machine came without the sound module. Is there any way you think to find one? and finally, Fifth: I found on e-bay a BPY10 photo-diode. Since you mention it as useful in your web page I purchased it, but how is it used? Thank you very much for the help you may be able to provide with these issues. And thank you for your generosity in sharing your knowledge in the www.

A. Lot of questions. There are only 3/4 variants of the Vox. It was available 1st in a silent version, known as the "S". The doubt over 3/4 is because I don't know if both Vox and Super Vox were sold in this way. There are just the two sound machines, the Vox, with the 15v 200w lamp and the Super Vox with 31v 400w. If you look in the picture gallery, part 1, near the top are pictures of a Vox, complete with amplifier, an "S", and a Super Vox without amplifier. This is because I don't use the original amp at all; I put a cell such as a BPY 10 where the sound mirror originally fitted, and plug it straight into the mic input of an external amp. (You will find quite a lot about this in the Vox section). It is best to use a projector amp as they are specifically designed to cope with film sound tracks. Ditto speaker. I tend to use Bell & Howell a lot for the latter. Some of the principal differences are obvious from the pix. The Vox has switches side by side, the Super one above the other. The Super has an additional bearing support bracket for the lower sprocket. The Super has a bulge in the side of the base casting where the power feeds in, the Vox has this at the back of the amp. The Super Vox has a larger inching knob and a different lamphouse, partly to accommodate a larger motor. Even with a Super Vox, it is advisable to give the motor a hand when starting, and the Vox was notorious for needing this. It matters because if one were the sort of idiot who turns the motor off leaving the lamp switch on, when restarting, if the motor refuses to turn at once, you have a hole in the film. Both the original lamps are almost impossible to find and probably don't give such good results as modern ones. They also have a pretty limited life - 30-40 hours maybe.

The Vox is easy to convert as there is a 15v 150watt halogen lamp, in both "peanut" and dichroic mirror types. The dichroic is I find too difficult to
fit. My earliest conversions were by fixing a lampholder to the side of the lamphouse, with the lamp horizontal - this works for both Vox and Super. I  prefer to use a system that does not change the machine, as I have shown on the site. Unfortunately, I let my conversion go with a projector and will  have to start again, but it does make converting the Vox simple and above all non-damaging. If you get the lamp filament into the same position as the original, it works fine.

The Super Vox is more difficult - there is no commonly-available 31v lamp to use as a direct replacement. The transformer in mine was unwound a bit to give 24v, so as to allow the use of the 24v 150w or 200 or 250 in peanut or dichroic - with the dichroic you just have to scrape off a bit of the silvering to allow light thru for the sound track.  I have a number of Vox and Super Vox machines in various states of completeness - or not. There is a good chance I could provide any spares you  might need. And I am happy to advise on any particular problem you encounter. Note that one of the weaknesses of these machines is that the main drive  gears can wear, particularly on the Vox - the precise alignment of the motor is vital.

Enough for now. Do some more reading and get in touch again. You sound very literate and are doing interesting stuff. If you go back as far as an entry  dated 1st February in my What's new section, you will see extracts from Flickers. Either a subscriber or a writer of stuff for it is always welcome.

Q. Thanks a lot for your generosity and patience. I will research and do some more, no doubt. Anyways, my Vox seems to be working fine, mechanically, so I will work on getting a light source and adapting the BPY10 as you have done. One thing is pretty evident; the lens is quite dirty inside, so I have to figure a way to disassemble it and clean it. It's a 32 mm, identical to the one my Pathé Lux uses. Any chance that you would have a spare original sound module to sell? And thanks a lot for the FLICKERS tip!

A. The sound side of a Vox comprises the amp in the big case at the back and the sound drum/flywheel assembly. Which are you missing? And are you clear  yet which Vox you have? The lens is probably not worth bothering with. I remove the glass and bore out the inside of the lens sleeve to fit an old-style B&H lens, which are quite common and of far better quality. The same thing doesn't seem to work as well with a Lux, oddly enough. Equally oddly, I am currently working on a Lux, fitting a new motor speed resistance and converting the lamp to halogen, without harming the original machine. I have decided it's time to get in touch with my inner Lux out and will be studying it quite closely, especially the notching system. PS my other half is Membership Secretary for Flickers - please send money!

Q. I am sure I have the Vox. The box part, on the rear, is missing: does that hold both the amp and the drum/flywheel assembly? It does have the mirror and the lens device to throw light onto it. But someone in its past life removed the sound components. My Lux is OK except that the shutter is quite unsteady. If I carefully apply pressure on the gate/plate it becomes steadier (and slower) so I guess something is out of alignment in the shutter/registration pin zone. But I haven't been able to figure it out. The notching system works well nevertheless. Which brings me to asking you if you know of the existence of repair manuals/schematics for the Lux and/or the Vox.

I will definitely will be subscribing to Flickers!


aunt-m aunt-m aunt-m aunt-m aunt-m

Here are some pix of the sound unit. It sounds to me as tho you have an "S" projector. Did it have the cover under the lamphouse (in place of the sound unit) that is shown in the "S" pic on my site? The pix are of a Super Vox unit that is from one of the (many) projectors I have part-dismantled, but I don't think the Vox is any different. I have put numbers on some of the pix to help. Most of it is self-evident. The knob A has a tip A1 that contacts the side of the projector when it is in situ. The spring-loaded screws B allow this to move the sound telescope in such a way that it pivots around some ribs on the back of the bakelite bracket holding the lens tube. The effect of this is to move the light beam to and fro across the width of the film sound track, to allow for the variation in position of said track that was a feature of 9.5. Screws at C, D and E provided adjustment for focus and alignment of the beam of light, which comes from the main projection lamp. I suppose it might be possible to take a module from one of my rather defunct projectors, but it would mean destroying any hope of ever getting it running as a sound machine. It depends how much you are prepared to give me. Pretty much all I know, and all the associated paperwork I have, you will find somewhere on my website. Not the Lux instructions yet - still in progress on that. Your Lux problem sounds like you have a YA, which is the earlier model with small lamphouse. The later YC has a bigger lamphouse and uses a lamphouse cap the same size as the one on the Pathescope 200B. This is much rarer. The trouble with the more common YA is that the gate is made of Mazac (aka Zamac) and as such is prone to distortion. This could well be giving the problem you describe.

Re B&H, it's the 16mm lens from the old 620 etc series - no particular make, but obviously bloomed is better.

Q. I realize that my understanding of the PathVox is not as good as I supposed: my machine does have the sound module you sent in pictures. I just don't seem to see the "D" screw in your picture anywhere, even if I take out the lamp house fully, (including the "second layer" that holds the reflector for the lamp to concentrate the light beam thru the image lens). I guess that what I'm really interested in getting (for the sake of making the machine "complete") is the "box" that comes behind the machine. I assume now, this should be the amplifier? Also the fan to cool of the lamp is lacking its back cover, which might or not be part of that "back box" of the Vox. Mine came without that too. I'm attaching a couple of pictures of my Vox unit, to make my descriptions, hopefully, more clear.

When I got my Lux, its lamp socket had already been tampered with. When the bulb it came with gave out I had to redo the socket to the best of my ability. I adapted a CEW/CFE 120v 150w which works fine. All of this to say that I can't tell if its a YA or a YC. I have taken also three snapshots of my Pathé Lux machine, showing the piece of cork (ugly I know, but the unsteadiness of the projected images otherwise exasperate me) I have devised as a temporary method to achieve more stability. Also I photographed the removable gate. It seems to me like the claws do not retract enough or are maybe a bit worn in the tip, making them too thick to do a proper job. This by comparing the claw movement in other projectors. Maybe they are made of the weak alloy you indicate? I wonder if there is a remedy for this.

A. Thank you for the pix a picture is worth a thousand words. I'm not happy with your sound lens tube (sound telescope). It should protrude through the bottom of the lamphouse; the hole in the bottom of the lamphouse is bigger than the tube, to allow it to move as I have already described. In order to prevent light spilling down this hole and causing hum, there is a little cover that slides over the top of the tube, and moves with it. Ill attach a pic of one.

Are you sure you mean screw D and not screw A? Can you send a more close-up pic of the sound telescope, please? If you do mean screw A, it may well just be a case of finding another that fits. Inside the tube there should be a slit, formed by two semi-circular plates that don't quite meet. This can be adjusted - a narrower slit means better treble response but less volume, so it depends on how your particular set-up works. I would not touch this for now. It is accessed by unscrewing the top of the tube. I'm not sure without looking why there are two screws at D - one should control the angle of the slit, which must be absolutely square to the film.

I suggest you go to this page of my site There are here just a few example pictures from a large number of spare part pictures. If you give me your address, I can send you a CD-ROM with them all on, and looking rather better than the examples. Both the Lux and the Vox are covered, so they could well be useful to you and in identifying between us exactly which part we are talking about. If you want to send money for a subscription to Flickers, and for the CD, I take PayPal and will walk into the next room to give your sub to the membership secretary for you. Then you could just email the form.

I have had this problem with the back cover missing from the Vox fan and made a new one out of aluminium sheet - there's a pic on the website. I think I kept a template, so I could help with that. As to the amp usually, the contents have been thrown away or replaced, so you won't get an original amp. Also, it does add to the weight; a Vox is 15 kilos without it. The two attached pix show separately the amp casing and the base into which it fits. Note that the terminals at the rear of the machine are not the original power input; this was at the back of the amp. The three wires are for 110v, 130v and common. You should find the 130v and 110v marked on a terminal strip inside the base so you can find out which is which. I usually eliminate the 130v connections and use the third terminal as an earth.

Your Lux looks like a YC, with an all steel gate and bigger lamphouse. Without looking, its hard to say what your problem might be. I take it the gate springs are OK? The two leaves bed together neatly? Is the tension device that holds back the top spool working properly ditto bottom spool? Unless its been damaged, the claw is unlikely to be the problem - it's made of hardened steel. The problem with all old projectors is that they are temperamental, and can need a lot of time and attention to be made to work properly, as can be seen from my own experiences as recounted on the site.

Re lamps, you are aware that the Lux is basically for notched films and if you use too powerful a lamp, the film will be damaged when the machine stops for the still frame.


I'm attaching more pictures, all CUs of the sound telescope in my machine. I screwed "A" all the way one way and then in the other way and then took out the little cover (your picture "Vox sound unit 008.jpg") and then also the "B" screws to show you that the two screws you mark as "D" (now I realize they are two and not only one) are not present in mine. The amp I guess is the part photographed in "super Vox 007a.jpg" , I believe. You say I won't find that, correct? I see a unit similar to mine with the exception of that part, the amp and the base I assume, in your site (photo gallery, second picture down on the right hand side) As for the Lux, I believe the gate and the loop holders are fine. So I will keep trying to figure that one up. 
I'll be happy to get the subscription thru you and also the CD and any helping documents you may be able to send me, as the fan cover template you mention. (Maybe another template for the lamp adaptation? That would be very helpful) I know the subscription is 21 British Pounds. How about the rest?

A. I can only assume the D screws are a difference in the Super. The amp at 7a has obviously been much modified - most of those controls and sockets were simply not present in the original. And it's a Super. The empty case in the pix in my last but one email is for a Vox. If you offered me lots of money and were prepared to pay a hefty shipping charge, you could have it, I suppose. That aside, the only cost is 3 for the CD-ROM, unless you decide to buy the  amp thing, which we can discuss separately. So just send 24 PayPal and we'll start your sub with the issue published last week, and I'll put the CD in with it.  I will try to look out the template and decide how best to help - will take some time, I fear. I don't think I have a template for the lamp mod - I made  a mistake and sold the projector it was in before copying it.

Q. I managed to make the light work on my Vox, following your guidance. I just want to share a few snapshots of the unit I built, using the base of aunt-ma burned out lamp that I was told by the guy I got the Vox from, was the lamp the Vox used originally. It turns out he did not give me a A1/105 but a A1/52 and I had to file it down to have it fit the Vox socket, once I broke the glass and got rid of the guts of the burnt lamp. 
Also I decided to connect the EVB directly to the wires and disconnect them from the socket terminal, to avoid the chance of having a short circuit or something even worse. The first 15v 150w peanut lamp got burned. I had measured the voltage in the lamp socket 16v DC but somehow when I got the EVB lamp connected it was 19.5 AC if I connected the 110V wall input. And now the 130v input gives the lamp 16v AC!. I'm pretty sure that a few days ago both were 16v DC. Maybe I just made a silly mistake, but I seriously doubt it. In any case 16v AC works fine now.

The projected image was very jerky. I discovered that the film gate is way too wide, and for the moment made a cardboard "T" that I placed in the feed end of the film gate, that works a makeshift "pressure plate" and makes the projected image steady. I will have to find a more elegant way to address that problem later. Also I think, having projected a silent Laurel and Hardy, that the motor is running under 24fps. I'll also have to look into that some more. But what puzzles me now is that the light from the sound telescope doesn't seem to hit the film. It hits the mirror but not the film.

My BPY10 just arrived from England yesterday and seems to be working fine: the volt meter shows an increase when the photodiode is approached to a light source.

A. Hmmmmmmmm.
The Vox has a problem with wear to the sides of the gate channel - much of it is due to that silly sideways shift between top sprocket and gate, which places a lateral pressure on the film. The channel being cast in fairly soft metal does tend to wear. The ideal solution is the have the sides milled out and replacement "runners" made of steel fitted. This I have not yet tried as my engineering skills are limited. I have also seen machines with a pair of rollers above the gate to get the film into position and so avoid the lateral pressure.
The motor speed is determined by a) the gear at the front and b) the frequency of the mains supply. It is an induction motor and runs at a fixed speed which depends on the mains frequency. We have 60 cycles per second and the US uses 50 - or vice versa, I never can remember which way round it is. Have you got a condenser/capacitor? This is critical not just to starting but also to running at the correct speed.
Send me a pic of the rear of the sound telescope holder, and we'll look at it then.
Incidentally, you seem from the pic to have the lamp filament arranged fore and aft. This might just be the angle of the view. Anyway, the filament should be across the projector, presenting its broad face to the condenser lens.

Q. You were right about the position of the lamp. I corrected that the best I could, and tried to put it as close to the condenser lens as possible. That seemed to help also the sound telescope. But I had to open it up and I discovered that mine had the slit thru which the light passes almost closed. I had to unscrew a lens part to access four small screws that hold the two halves that make the slit and I fixed them so that the slit was as wide as possible.

The light is now barely touching the film side but in order to achieve that I had to let the sound telescope loosely attached and help pushing it towards the projector. Still it seems to me it hits it barely. But the sound telescope can't be pushed any more without modifying the aperture thru which it comes thru in the lamp housing. In other words, if the hole was wider or simply elongated towards the outside of the projector, that would allow me to have the light from the sound telescope hit the film optical sound area more centred. For the moment I think it's off axis. But I can see a brilliant point of light in the edge of the film now. I feel that is progress.

A. No no! Slit must be as narrow as possible or you will just get muffled, bass-y sound if any - I usually try to make mine even narrower than original as I'm usually either getting better light or better cell performance.

aunt-mHere is a pic of the back of a Vox sound reader. You will see at "A" two horizontal raised ribs, and a vertical one at "B" - that is to say, vertical when the reader is actually in place. There should be on the body of the sound module corresponding slots. These are to enable the reader to pivot slightly to allow it to read the track and get into the best position. I have had similar problems to yours in the past. Your best approach might be to take the whole sound module out so you can see what is actually happening where the reader meets the body of the module. It may well be necessary to file some of the ribs down a bit, but be very cautious. I have known readers that could actually move in first one direction and then another as I tightened the adjusting knob - it's a very weird arrangement, but you should be able to make it function, certainly better than it is at the moment. I assume you have ensured the springs are not too tight, to give it room to move.
Another possibility that occurs to me is the position of the sound drum. It has needle-point bearings at each end and there is scope for some adjustment of the position of the drum, and therefore the sound-track. The basic point to remember is that the system does actually work, so if it doesn't, it's because something is wrong.
About the lamp. Be careful not to put it too close to the lens - there is an optimum position anyway, and putting it too close may risk heat cracking the condenser lens, which tends to be visible on the screen. You can check the optimum position by running the lamp with a lower voltage so you can still see it on screen but are not blinded by the light. You can then fiddle to find which position gives the best and most even illumination.

Incidentally, I find it good practice to run a loop of leader thru the projector a few dozen times before serious use, then check to see if any scratching occurs. Prevention is better than cure.

Q. I have put the slit back to minimum as you advised. I have also looked into the sound drum. I managed to make the film (I think) shift a little bit out. But the sound telescope still only hits its side, too little I think (without having any optical sound film in hand). Looked into filing the parts you indicate, but I'm still convinced that the problem is that the sound telescope can't point inwards enough because it hits the hole in the lamp housing.

It will be great if you can help me with some test film. If you do find something suitable you can live without, please let me know how much I should send you for it and its mailing. I really appreciate a lot your kind help. I guess I will start setting my photo diode and figuring out connections etc. while I get some sound film. Any guidance on that respect, again, will be highly appreciated.

By the way, I have been assuming that the sound telescope's light should hit the edge of the film and not the mirror. In my machine the light can easily hit the mirror, but I find that illogical. Unless I'm missing something...Looking again more carefully at the sound reader and its insertion on the projector I realized that you where totally right in suggesting to file those ribs. I did a bit of filing on them and already the light beam seems to get better where it should. I decided to be cautious and not go too far yet, before testing the actual performance once I'm ready to do it. So in other words, there is still room to file some more those ribs. Also, I managed to get the actual tube very low, just millimetres away from the film, thinking that that may help to get better light onto the sound track. But putting a piece of paper underneath the beam to see where it goes and how it goes, I feel that it is maybe too diffused or out of focus. The same beam in the same piece of paper looks sharper lower down. So I'm wondering if I'm making a mistake and the tube should go back and away from the film, in order to get a more focused light beam. Should I simply find a way to attach my BPY10 under the film so It catches the light as best as possible? I guess so. What do you think?

A. I have had another thought. There may be a bit of adjustment possible in the position of the sound module. If you were to slacken the bolts that secure it to the base, this might allow you to move it a bit and help avoid the reader hitting the side of the lamphouse. As for height of the sound telescope, I suggest you study the pictures in my section on the Vox - bound to be some pix there that would help, tho' be a bit wary in case Vox and Super Vox are different. I have always worked by looking at the light on the film - what you should have is a very thin strip, only tenths of a millimetre thick and about 1.5 to 2mm across. It should look as sharp and clean as possible; the point of focus is the film, not the mirror, tho' ideally one does fine tuning by adjusting while running a film. As for the mirror, bear in mind it has probably got a fair bit of adjustment, so the light hitting it or not may not be a very good guide. You can fit your BPY10 by removing the mirror and fitting a small bracket, as detailed on a certain website.......

I have despatched to you by air mail a (part) sound film and one of my lamp adapters for the Baby - I am making a small batch due to popular demand. You will learn that the worst thing about 9.5 is the people who use it or, more accurately, ab-use it. I have attached a copy of a piece I did for another of our film mags, specifically for 9.5ers.The film will confirm much of what I say. You will see two bits of paper sticking out of the reel of film. Between these two, the film is junk and should be thrown away, I just left it in to show you how awful it can get. The bit taped on the front of the film is one of the worst bits. The rest is not brilliant, but should provide you with decent test footage. In the first part of the film, before I gave up, you will see examples of the kind of repair I do, as described, of course, on my website. When you see what the film is, you will understand why the idea of you playing it repeatedly there in Mexico affords me a smile of amusement (He will find it's the Trooping of the Colour)

Q. That is a very pleasant surprise! THANK YOU VERY MUCH!!!

I will try this new adjustment you suggest. And it makes a lot of sense to have the light beam focused at the film. Should I simply find a way to attach my BPY10 under the film so It catches the light as best as possible? I guess so.

I'm curious about that template you have for the rear motor cover. Fortunately my 13 year old twins are not as naive as they used to be still some years/months ago, but one of them already asked me yesterday (pointing his finger to the revolving blades, but cautiously away from them blades) what that was... So it's my hint to get that covered asap.

Great funny/sad text you sent me. You can imagine that I find a lot of the same in my part of the world. I'm patiently going thru a big box of assorted 9.5 400ft rolls I purchased in a local flea market with some jewels I think, to be recovered. For example, there is this 400 ft roll of a Mexican tenist group of the 1930s that seem to have had sessions not to far from my home in place (Tacubaya) that was then countryside and now has a totally urban landscape. I treated it last year with vitafilm for three months with some success, and I'm still fighting to revive it. It tends to curl inwards because of improper storage. I'm thinking about immersing it in a water bath (like the ones one would use after processing to clean up left-overs) and re-dry it in my US Army manual film dryer. Of course, I have to do some tests before with expired 16mm raw stock, before I dare to do that to my cherished piece of forgotten history. It will probably have to wait some time until I have the leisure to try that.

When I get Pathé baby spools one thing that happens a lot is that they detach from the core. I haven't been able to figure out how to properly re-attach them. The Pathbaby spools don't seem made to be disassembled, which would make sense. Any ideas on that issue ?I got the B&H projector lens I found on e-bay to replace the original one in my Vox. The difference is indeed amazing. Its a Super Proval 2 inch 1.6f and had to do some filing on it to get it to the lens housing far in enough to get focus. But once I managed to do it, the projected image was great. I'll have to work on the lens sleeve to make it a more permanent job. Its getting there.
A. I apologise for being so stupid. I was fixated on the idea of a template I thought I had. It has taken me all of 10 minutes to remove the back from a Vox, trace round the cover, make a cardboard template, take a few photos and write this. Some days, my brain hurts. I will send the card one by post next week. Note that the screws do not go thru the cover; the heads of the screws hold it in place.
The Baby cassettes are designed to not let the end of the film come out. Each film has a slot formed by joining 3 perforations at the end; this is far enough from the end to ensure that the film stops (nothing for the claw to work on) before there is any pull on the film.
The film is secured to the core of the cassette by spring clips. The one I am looking at has a spring clip inside the cassette, round the core, with a gap so the film can get thru the slit in the core. I am not sure what this is supposed to do - it's very difficult to do anything with it - I assume it was extra fixing added during manufacture.
In addition, there is a similar spring clip inside the core, but outside the cassette. You can see this in the attached picture, as I have removed it - it's easilyaunt-m pushed out from the side with the slot in the spindle for the rewind. Now, it's a very long time since I fiddled with a Baby cassette, but memory says you feed the film thru the slot in the core into the centre and the put the spring clip in so it traps the end of the film. It may be possible, too, to twist the clip inside the cassette around a bit so it helps to trap the film.
Pathused to sell a little two-ended device; one end cut the notches in the side of the film, the other cut the slot down the middle of the film to ensure the film stopped in time to avoid pulling it out of the cassette. (You will see three examples in the second pic down on the left on the website page on Gear, which is accessed from the main 9.5 page.) Perhaps you have this vital slot missing on some of your films, or are using a different projector whichpullsthe end before it reaches the slot?
As you can no doubt see, the construction of the cassettes is such that taking them apart would be hard and putting them back together properly almost impossible.



Q. As you dissected a AndrDebrie 16mm-projector I hope you can answer a question which has kept me busy since someone told me: "I don't know if it is a good idea that you bought that old projector from a woman who had never used it. Oil has certainly clotted in the thin pipes of the oiling system." And indeed it seems it has. How can I change the oil? In spite of the fact this pre-war model of a projector looks awfully solid I am a little afraid to break something crucial. I hope you can to help me.

A. Please bear in mind that my only experience is with the grey D16 model.
I would be very surprised to find that oil has solidified as you suggest. Do you have any particular evidence for this?
What I did find was that thin oil will not work in this machine. The oil is circulated by a fairly basic mechanical pump and it needs quite thick oil - car engine oil sort of thing - to function. I assume you know about the oil flow adjuster at the top.
You will have seen the drain plug at the bottom of the lower oil reservoir. You can drain the oil quite simply through here. If there is a serious problem of clogging, you may be able to use a specialist car product designed to flush an engine. This may be preferable to dismantling, but I wouldn't worry too much about taking the machine to bits - it was
specifically designed on a modular basis so complete assemblies could be easily replaced. You could try mixing thick oil with something like WD40 to flush the system through, but if it's too thin, it won't go round. I think the whole front section will come off if you remove the screws on the perimeter of the round section - just take the usual care not to lose
anything. You will need to do this if you decide to open up the lower oil reservoir - one of the two screws holding it on is only accessible if you remove the front section. Please think carefully before doing this - there are oil seals top and bottom of the reservoir which you would have to make watertight (and oil-tight) again. Also, if you are afraid of breaking
anything, the glass of the reservoir is one of the most breakable parts. Best left alone. You can remove the oil tube running from top to bottom quite simply just by undoing the two nuts - these again form oil-tight joints, but should I think go back OK as I think they rely on compression rather than seals. I think the first thing to do is drain whatever oil is in there and try some thick oil. However, if it is really true that oil was never added, there may be mechanical damage. This machine is designed to run with a constant flow of oil and if this wasn't done, either from lack of oil or failure to adjust to
keep the flow going, it could ultimately seize up.



Q. I recently acquired a very nice Heurtier HSM (or is it a Panoralux?) multi-gauge projector. The machine is in exceptionally good condition and appears to have had little use, however it has been unused for many years. The result was the gear box speed changeover was seized in the 24FPS position. After clearing out the old gearbox grease and generous use of Plus Gas on the seized components I eventually got the seized components freed off and the speed changeover nowworks as it should.
I am puzzledby the following;set up for 16mm, the machine can be turned over with the inching knobfairly easily; set up for 9.5mm and 8mm the machine becomes quite tight to turn over although it starts and runs OK with the motor. Is this normal?
The instruction book indicates a lever on the sound optics to adjust for the narrower track on 9.5mm. This lever is not fitted to this machine. (I think I could see a similar machine on one of your web photographs i.e. without the changeover lever) Any comments on this?
Do you have a circuit diagram of the amplifier and exciter lamp supply?
A. As far as I can make out, the only difference in the Panoralux is that it has a Debrie-size lens mount, not the smaller type as inthe silent Heurtier and my very dirtyoptical-only machine.Bit concerned about the difference on inching between 16mm and the other two. Could be that it has mainly been used for 16, but even so - I assume you have oiled the claw? I have a very little used machine that is very stiff altogether. But if it runs without weird noises.......
All three of my machines have the 9.5/16 adjuster - it can be seen very clearly on my website in the picture of the stand-alone Panoralux, back of sound tube near exciter cover. I assume you have the same daft exciter lamp (tho' my double-band machine had been converted even beforeI got it). I have found a spare on French ebay, but they are like hen's teeth. No diagrams, I'm afraid - I wonder if anyone has them?

Q. My machine appears to have the smaller lens mount so must bethe HSM model. On your converted exciter machine has a "Elf" type lamp been used for the job? I attach a couple of pictures of my machine which show the absence of the scanning slit changeover lever. Any ideas why this should be omitted? May have to take the optics off and narrow the slit to 9.5mm size as this is what I will be mainly using the projector for.

A. I can think of only one answer, as it's obviously meant to be that way. I have heard it said that in the old days, cinema projectionists would narrow the sound slit so that the beam only picked up the least worn part of the track. I suspect Heurtier may have found that, if the set-up had enough power to produce a good volume from a 9.5 track, why bother with expanding it for 16? The corollary, of course, is that it was mere penny-pinching and they left it 16mm size, not caring what happened to 9.5. I assume since you are considering the extreme step of dismantling, you have already tried the 9.5 sound and found a problem, which would tend to favour the less favourable of these two possibilities. The lamp conversion on my double band used a slightly smaller bulb, 24v 10w, small bayonet with 2 pins, with 2412 U and Bay 15 on the box. I've not come across them, but I've got a small stock so haven't looked. It might not work for you anyway; at the same time as the lamp, the photocell was changed, too, to a solar cell/diode, which might give higher (or lower) gain than the original.

Did you note the bit in Multi-Gauge about using a reversing prism and running the 9.5 film the wrong way round? I find it very difficult to get a tenable loop at all with that twist, and it must put a considerable strain on the film. A square piece of wood the size of the 9.5 sound aperture placed in it and twisted turned the mask thru 180 degrees for this.

Q. I have finally got all the facilities on the Heurtier running OK with the exception of the sound on 9.5mm optical. I removed the sound optical system with a view to masking it down to 9.5mm width but found it to be a sealed unit and I was reluctant to try to open it up. (The masking down has to be made close to the mechanical slit inside the unit) so I refitted it to the projector unaltered. The problem is, with the 16mm slit width the 9.5mm track is scanned plus the area either side of the track resulting in heavy background noise.

A. Are you sure the masking needs to be done inside? I know Tony Reypert used external masking on at least some of his Buckingham 9.5 conversions, to deal with exactly the same problem. Worth a try,I would say. I can't see any reason why it wouldn't be at least as good, at the bottom at least, as inside.
One of my Rurals has got a thing at the top of the sound lens tube that you rotate. It has eccentric masking so that more or less of the sound tube is covered. I did think of doing this sort of thing myself for something, some time ago, although at the bottom rather than the top, but I have forgotten what!
As for it being a sealed unit, if by that you mean that the screws have some sort of seal over their heads, I wouldn't let it worry you. You can't do much to a Heurtier without breaking some of these, and it's not as tho' you might need to make a claim under warranty and need to prove you haven't done unauthorised fiddling.


PathBaby motor

Q. I have a question about the PathBaby motor. I recently acquired one from Buckingham films, and it works fine on the 115 v 60Hz here in the USA. But I am somewhat concerned about it's safety as the internal wiring looks pretty bad and the connections to the mains terminals look pretty dangerous. I am considering taking it apart and attempting a rewiring job. Would you advise this or not, and how difficult a job is it? Any pitfalls to watch out for, or any recommendations?

A. First off, make sure you have a really good earth connection, and use what we call an RCD (Residual Current Detector, I think), which trips out if something's wrong.
Second , be careful, and remember to be careful always, which is the hard bit. Try to get the mindset that NEVER takes a chance.
These two should keep you pretty safe. As to the wiring, the bit that matters most is where the wires disappear inside the motor casing. If these break, and being old and brittle they might, you have a problem. Leave them alone as far as possible, and don't let them get bent if at all possible. If you have this problem, we need a more detailed look, ( it's fix-able often, but tricksy) but I'll assume for now you don't.
Anything downstream of the aboveyou can replace with impunity, but watch out for the resistance for the speed control. These wires, too, can be very fragile, and altho' you may be able to replace with a modern device (eg a light dimmer), it's a lot of hassle and a shame to have to do it. The contact on some can get stuck to the wires and break them; the stuff the wires are bedded in tends to disintegrate and maybe let the wires move - the first step towards failure - and you may get corrosion on the contact, causing extra friction and poor conductivity.
Things I find especially useful in this context are heat-shrink plastic sleeving, which can add strength and support as well as insulating, tho' it's a bit inflexible, and some insulating rubber solution I got from a supplier of car restoration stuff. You can get it into all sorts of corners where you can't wrap tape, which doesn't really last anyway. This could be useful where the wires go into the motor casing. It is also possible to get the resin-impregnated sleeving used in the old days, if you want to do a pukka restoration.
I have a number of old Pathé Vox machines, which use a 3-pin input plug, two of which are the same, just connected together. Isn't the Baby motor similar? I have used one of the duplicates to provide an earth, but I have to put a label on theprojectors I've converted as, if they were connected to an unmodified input, you'd get a live casing, not generally considered good practice (!)


Lamp Conversion

Q. I am trying to fit a 12v 100w dichroic mirror lamp to a Bolex (maybe 24v 200w would be better). I have made an adjustable bracket using a lampholder from an Elf 16mm machine. How do I position the lamp to get the best light? What are the criteria?

A. There is only one criterion - what it looks like on the screen. There are specific focal distances for such lamps (some are quoted in Lamp Data), but these are more use to manufacturers of projectors than to the amateur. The distance is apparently measured from the back of the mirror rather than from the filament for one thing, which makes it more difficult, but anyway, it does not address the issues of lateral and vertical location, which are just as important. There are variations in focal length, there are primary and secondary foci, there are differences relating to the size of the gate aperture you are trying to illuminate (unhelpful if you are attempting to deal with a multi-gauge machine, especially if 8mm is involved. The tri-gauge Bolex G3 had a special lens to deal with the offset of the 8mm aperture, but the lighting has obviously to be a compromise when there is a 3- or 4-fold difference in aperture).

So at the end of the day there is no practical alternative to good old trial and error. The way to do this while keeping both your fingers and your sight is to feed a reduced voltage thru to the lamp - 6v should be ample for a 12v lamp, and you could probably manage with it for the 24v lamp too. (Don't go thinking "Ah yes, halve the voltage", because you will literally get your fingers burned if you try that with the higher voltage lamp.) This should give you a level of light sufficient to gauge the best lamp position, using a small screen a few feet from the lens, with a reduced level of heat that should help with handling. It's still a fiddly job, but is much eased by an adjustable holder such as you have - once you get the position approximately right, you can fine tune. You may have noticed that with some projectors the lamp glows when the projector is on. This is supposed to warm it, prevent thermal shock and prolong lamp life as compared with going from cold to full power. This question of lamp life seems to have exercised amateurs quite a bit in days gone by, judging by old copies of Home Movies and Home Talkies, for example. This uses just a couple of volts at most; what you need is just a brighter version.

Don't expect to get a perfectly even illumination - you need to go for the best compromise between evenness and brightness. Once you apply full power, and with a film in the gate, it will be impossible to detect any unevenness. One final point - disengaging the still frame mech to avoid accidental operation might be a good idea.



Q. Do any operating instructions exist for the Pathé KOK 28mm projector? if not, can you tell me, what the small knurled disc on the main body just in front of the gate, with what looks like a ball bearing in the centre is for? I assume the hole (with cover plate) just under the lens is a oil hole?

A. Mais naturellement il y a un manuel! Vous le trouverez sous 28mm, nommé Instructions. Malheureusement, le manuel est en Français, ce qui pourrait poser quelques problèmes pour ceux d'entre nous qui ne peuvent pas hacker le Froggo. En plus, le manuel ne traite pas des trous dans votre question, mais il serait étonnant si tous les deux ne soient pas pour l'huile.


Emulsion in or out?

Q. Which way round does the film go thru the projector? Which way does emulsion face? Which side of the spool does the film feed from?

A. This is all the fault of Path who made their silent films, up to the time sound was introduced, unspool from the back of the reel (ie nearest the projector). No other film does this as far as I know. It may be because of the gauge's origins in 30ft notched cassettes. The emulsion had to be on the inside to protect from rubbing on the metal cassette, and the design required a feed from what would become the back of the reel.

The important thing is not the position of the emulsion (unless perhaps you are loading film chargers?) but whether the film appears OK on the screen, with titles the right way round, right side up, from the start rather then the end and preferably with the sound track on the correct side. If all of these are right, who cares about the emulsion? It does matter, of course, because projectors are designed to minimise any rubbing. The emulsion is on the inside of sprockets, away from retaining rollers, and rollers that take the film round corners do it with the emulsion on the outside wherever possible. With 9.5, there is the unique factor of potential claw scratching in the picture area. It makes sense, therefore, for the emulsion to face away from the claw. We have all seen the damage a Baby claw can do. It may well have been this that ultimately made Pathchange (the Vox, H, 200B, Lux et al all have the claw in front of the film). I seem to recall some reference in the amateur cine press or maybe Pathescope Monthly on the reasons for the decision - anyone got chapter and verse?

So, basically, except for most 9.5 silent, feed from the front of the spool (or underside as I sometimes think of it), and never mind the emulsion so long as the film is right on the screen. Sometimes this means a twist in the take-up belt to get it to rotate the right way. It's not the end of the world if a film takes up the "wrong" way, tho' it can mean it winds floopy and could mean problems if the film is near the normal maximum capacity of the take-up spool.


8mm Gauge terminology

Q. What is the difference between Regular 8, Super 8 etc?

A. Regular 8, Normal 8 and Standard 8 are all terms for the first 8mm gauge. This was created by doubling the number of perforations in 16mm film, and having four images in the space previously occupied by one 16mm image. The film was produced 16mm wide, and run through the camera twice, (hence "double-run" 8mm) then split after developing. The advantage was much greater economy both in film used and in developing. Kodak introduced the gauge in America in 1932, and shortly thereafter it came to Europe. Eventually, magnetic sound was added and experiments were made with optical sound; one or two projectors were made able to run this, but remained curiosities as there were no films to buy.

This was because Kodak introduced Super 8. This was widely suspected of being a marketing ploy to get enthusiasts to buy all their equipment all over again. However, whatever the truth in that suspicion, there were sound technical reasons for the change. The Standard 8mm image was tiny and, although capable of producing excellent results, was a highly inefficient use of the film area because of the (relatively) giant 16mm sprocket holes. Adding sound just made things worse - tiny tracks straining to produce acceptable results, or yet further loss of image area. Super 8 had very small sprocket holes (too small some said, concerned about how long films would last) and an image that was both wider and taller, even with a sound track (magnetic for the most part, but optical particularly for use in aircraft entertainment systems). A magnetic sound track adds thickness to the film on one side, so a "balance" track, squeezed between the sprockets and the edge of the film, was added, which was exploited to give stereo sound.

At about the same time, Fuji introduced Single 8. In terms of format (film size etc.), this was identical to Super 8. The difference lay in the film cartridge, which was much more on the lines of Paths 9.5mm chargers than the squarer Super 8 cartridge, with feed and take-up one above the other rather than side by side as in the Kodak cartridges. The other difference was that Fuji used polyester-based film, stronger than acetate so it could be made thinner. This helped with the amount of film that could be got into their cartridge (9.5 never managed even 30ft) to match Kodak's 50ft cartridge. The only disadvantage with polyester (if you think it is a disadvantage), is that it can't be spliced with normal cement and so for practical purposes could only be spliced with tape. Polyester commercial prints can be found, looking suspiciously short on the reel for their claimed length.

The row about the introduction of Super 8 to confuse the existing multi-gauge scene was huge and rumbled on for years. Some of the sting was removed by the introduction of Dual-Gauge projectors for both Standard 8 and Super 8. Some machines even claimed to be triple gauge, citing Single 8 which was, of course identical to Super 8 (barring some projector problems arising from the thinner film base).

One problem that could not be, or at least was not, overcome, was projectors able to show Super 8 as well as 9.5 or 16. Standard 8 had a 16mm background and, by coincidence, the pitch of 9.5 and 16 was almost exactly the same. This meant (genuinely) tri-gauge projectors could be made (see Multi-Gauge).


Notched Films

Q. What are notched films?

A. When Pathfirst introduced 9.5mm, the maximum length of film in a film charger and in a cassette for the projector was 10 metres or 30ft. This presumably reflected the rather limited thinking about what was a very new venture. Later, 60ft cassettes were added, then Super Attachments taking up to 300ft. In order to get the maximum run time out of such a short length, Pathdecided to use still frames for titles, and often for the start of scenes or for static shots. The Baby projector had an ingenious device for allowing this. A notch in the film allowed a small cam to move, setting in train the withdrawal of the claw and a mechanism that automatically re-engaged the claw after a fixed number of turns of the crank handle. (The earliest Babies had a very long "dwell" time; this was later reduced as being too boring). This enabled the short cassettes to last for as much as three or four minutes, as opposed to little more than a minute if run without pause. This was all part of a total design concept; with all this stopping and starting, it was too complicated to have sprockets, and of course a low power lamp was essential to avoid frying the film. This in turn meant relatively low illumination levels, positively dark by modern standards but apparently more acceptable in those days of innocence.

The notches in the film obviously showed on the screen, so the film actually stopped a frame later to give a proper picture. An important additional feature was the provision of a slot near the end of the film, replacing the perforations. The claw could not operate, so the film stopped before it was shredded or ripped out of the cassette; the end of films was securely fixed to the tiny core in the cassette. An interesting sidelight is that the front ends of films were specially heat-treated to impart a curl to ensure smooth feed through onto the take-up in the base of the machine. Path actually patented this idea. Many printed films also had a very shallow but very sharp oblong notch in the opposite side to the main notch; I've never known why. (I asked an expert, the legendary Patrick Moules. He said that when triple prints were notched, before being slit, the notch was either slightly over-size or out of position, so that the outer part of the notch cut into the adjacent strip. This only happened, of course, with two of the three strips.) Notching devices were sold so that 9.5 film users could put the correct notches and slots in their own films. One other thing; many notched prints came from a period when the image quality was superb, which is why they are so prized by collectors.

The problem was that, as time went by, demand grew for higher levels of illumination. This meant more powerful lamps, that emitted more heat. Huge numbers of notched films now bear witness to the disastrous consequences; ignoring all admonitions to use the correct, low power lamp for notched films, users blithely disregarded the consequences, used the higher -power lamps and fried the titles. These then shrank and buckled or even burned right thru; splicing the damage out was a very limited option since there were so few frames of title to start with. Opening titles seem to suffer the worst and are often completely absent. At one time, Pathsold sets of running titles that users could splice into their boughten films, either to repair damage or for use on high-power projectors or ones that couldn't do notches anyway. Given Paths penchant for using lots of titles to disguise cuts made in editing, this can't have been very popular.


Light Output

Q. Why do low voltage lamps give more light than mains lamps?

Getting a bit technical here. As I understand it, lower voltage lamps can have their filaments more closely spaced, giving more intense light in a smaller area, highly suitable for narrow-gauge films (is it something to do with how far filaments must be apart at different voltages to prevent short-circuiting or arcing?). Another factor at play is that, for sound machines like the Vox, Debrie and GB L516 that used the lamp to read the sound-track, rather than a separate exciter lamp (which tend to be low volts/high amps - see the end of the table in lampdata.wdb), the lower the voltage the better. Lower voltage means less hum from the AC supply, I am told. Quite how this applies to 110 volt machines like the Debrie and GB L516 I don't know; maybe they deal with the problem in the amplifier.

Quartz Halogen, Quartz Iodine (QI), Tungsten Halogen etc. are all terms for a technology quite different from the straightforward incandescent lamp. They can be smaller, with smaller filaments, yet give brighter and whiter light, especially when combined with a built-in dichroic mirror, which removes the need for a condenser lens - a significant advantage for old projector nerds trying to uprate old projectors. So, for instance, the standard 24v 250 watt lamp with integral dichroic mirror gives a better light than a 1000 watt or even a 1200 watt incandescent. QI lamps need to reach a certain temperature to operate properly; I am told they also dislike direct cooling and can go black if direct cooling is applied, but they produce much less heat than the equivalent incandescent. They quite rapidly became the standard for narrow-gauge use, relegating the incandescent lamp to history. The peanut-type QI lamps can pretty much directly replace old lamps, tho' some experimentation with exact mounting position might help. Basically, I feel that if the filament is in the right place, then fair dinkum. Dichrioc mirror lamps have a specific focal distance; examples are in the lamp table referred to above. I think there may be more to be said on this subject; input would be welcome.

Then, of course, there are even higher power lamps. There was a version of the B&H 620/630 series with a carbon arc, the B&H 609. I've never felt brave enough to consider carbon arcs; complicated. Then there was the Marc lamp, which B&H in particular tended to use. They were some form of discharge lamp, and took a while to reach full operating output and colour temperature. They also needed complicated boxes of electronics, and used high-voltage circuitry. This last bit is also true of Xenon lamps, and some early machines had large separate boxes of stuff. Then came switched mode power supplies (I can say it but I don't understand it) which allowed much smaller boxes of gubbins and could therefore be fitted inside the projector. Most Xenon machines were 16mm pedestal models, which had lots of room for boxes of electronics, but there were some semi-portables like the Elf 2000 series. B&H also did them, but I've never seen one. I'm accused of being a light freak because I have Xenon's wherever I can 8, 9.5 (a Buckingham conversion) 16 and 35.

Beyond even Xenon in terms of potential for narrow-gauge users is the sort of lamp being fitted to digital video projectors. Bill Parsons converted a GS 1200 to one of these lamps, and a direct comparison with Xenon was arranged at a film convention; no question, the new lamp was brighter than the GS 1200 Xenon.



Q. Projector lenses are quoted for example as having a 1 1/2 inch focal length and f/1.9 aperture, but what does this mean? How does it affect the projected image?

A. In short, the focal length is about how big your projected picture will appear on the screen, and the aperture is a measure of how much of the light coming from the film is actually allowed through by the lens. It is, of course, much more complicated.

Most projector instruction books come with a chart that shows the size of picture you will get at various distances (the "throw") with various lenses. It should be obvious that what you get depends on what you start with - 8mm is going to give a much smaller picture than 16mm for a given focal length and throw. This is why lenses for 8mm machines have shorter focal lengths than 9.5 or 16mm machines. 16mm projector manufacturers were all convinced that their machines would only ever be used in modest-size halls or palatial mansions, as they supplied 50mm (2 inch) lenses as standard. These are about no bloody use at all in the average house as they give a tiny picture unless you knock holes in a few walls. As a result, 50mm lenses you cant give away, and shorter lenses 35mm or 25mm attract a substantial premium. Mind you, I look sometimes at the huge cost of new lenses and this puts things in perspective.

Because in order to have different picture sizes, or for different venues, you needed several lenses; zoom lenses were introduced for those who couldnt even change a lens. This was one area where Super 8 scored over everyone else the machines came with a zoom lens of a focal range appropriate for home use. Theses are often re-deployed to 9.5 in particular. Certainly, it was once true that a good prime lens would give a sharper, brighter image than a zoom, because there were by definition fewer elements stealing light or fuzzing the image. Given the advances in optics, I doubt that this is any longer true. Incidentally, it does seem to be the case that the shorter the throw of a lens, the more critical is focussing the tiniest of movements can destroy focus, where longer lenses have a somewhat longer travel within which focus is reasonable. The problem is not so much that its tough to focus, as the fact that small changes due to heat in the projector or lens can throw focus out and require it to be adjusted during projection. As with any lens, how sharp the image is comes down to lens quality. Larry Pearce once cannibalised very short throw lenses (20mm?) from Technicolor continuous cassette loop projectors and put them in mounts to suit certain projectors, eg the Vox. The quality of these was good and they give good results despite the very short focal length.

The other factor that comes into play is lens coating, or blooming. This helps to reduce light scatter and so improve both light transmission and sharpness. Since older projectors tended to have un-bloomed lenses, this affects image quality. Another problem with older lenses, or those exposed to damp or whatever, is fungus. This manifests as a spidery network of fine lines spreading across the lens. It then needs specialist attention removing the elements without damage, cleaning and re-assembly and re-cementing. (Terry Vacani tells me he does this details on request).

To come back to aperture size, the bigger the number, the less light a lens will pass. Whether variations are always discernible to the average eye is a moot point, but at one time there was a bit of a competition to see who could produce the fastest (most light thru) lens. I think Elmo pretty much won with a 1.0 zoom lens on the GS 1200. As a rule of thumb, anything 2.0 or less is fine, but bear in mind that the longer the throw, the higher the f number, so it is normal for a long-throw lens to have a higher number.


Buckingham Elf Conversion

Q. There is a conversion of the Eiki/Elf 16mm projector available for 9.5 silent called the "CLASSIC" it has fixed speeds of 18 f.p.s. and 24 f.p.s. I thought that silent film ran at 16 f.p.s., although I understand this could vary, hence the variable speed controls fitted to early machines. So why does the "CLASSIC" have only a fixed speed of 18 f.p.s.?

A. Most silent projectors have a speed control, usually a resistance or a friction brake. This is partly because the type of motor used runs faster as it warms up, and anyway each motor and projector would have slightly different characteristics, so the ability to control the speed was useful. The effect of load on motor speed is most readily seen in projectors with a clutch; run a film at normal speed, then de-clutch, and the motor races away. You get this with the Bolex PA/DA when it stops at a notched title. It was also helpful when showing all those mute prints of sound films to be able to speed things up a bit, so people didnt all look like they were in a slow-motion action sequence from films such as The Matrix. (How on earth did that silly idea catch on? And the idea that anyone can dodge bullets, or that villains are hopelessly bad at aiming their weapons at where the hero will be in a few instants time?)

This is no use when it comes to sound, which needs a constant speed, the smoother the better. You can of course use a governor to control the speed, but the motor needs to be powerful enough to run at the much higher speed of 24fps right from a cold start. The classic failure in this particular area was the Son (ugh). In order to get the motor to run at 24fps from cold, it was wound for 160 volts and fed with 240 volts. This is not good for a motor. Also, as the motor warmed up (which it presumably did pretty quick being over-volted), it went faster, so the governor had to work harder to keep the speed down, leading to interference with TV and radio and breakdown of the governor contacts. To minimise the damage, you needed to ease the resistance speed control back as the machine warmed up, but not too far, or the sound went slow. Sons (ugh) therefore spent more time back with Pathescope being repaired than with their owners. Because of their unstable speed, sound add-on units such as the ACE and the Aurator for silent machines were poor for sound.

Those who understand governors can skip the next couple of paragraphs, but I thought someone is bound to ask so Id better explain a bit. Any governor controls speed by a feedback system as the machine reaches the pre-set speed, the power is reduced to slow it down. In a projector, this usually takes the form of centrifugal "switches" on the rear of the motor. These are so arranged that as the motor speed rises, a small spring-loaded metal strip, fixed at only one end, is flung outwards by centrifugal force, breaking its connection with a fixed contact. The power supply for the motor travels through the circuit made when these two contacts are touching, so when the connection is broken, the power is cut, the motor slows down, the contacts re-connect, speed goes up, connection is broken..and so on, only very quick. On the more sophisticated machines, a screw adjuster is provided to help set the precise speed (usually two speeds, of course). On cruder machines including, regrettably, the Pax, you have to bend the afore-mentioned spring-loaded metal strip as best you can to set the speed entirely by trial and error. Mind you dont break them!

However, there is then the problem of actually establishing connections with the end of a motor whizzing around at high speed. This is usually done by motor-type carbon brushes running on brass strips around the surface of the end of the motor, on which the contacts we have been talking about are also mounted. Between them, the contacts and the brushes create sparks as contacts are made and broken at high speed, bringing a need for suppressors to prevent interference. You also need a resistance in the silent-speed circuit to take some of the load, so that the governor is not overworked as in the Son (ugh). Modern machines do it all differently and electronically in a way which I do not understand, so dont ask.

Anyway, to return to our moutons. The point of the foregoing is that sound projectors, which all modern machines are, have essentially fixed speeds that cannot be varied as on old silent machines. So the Classic, which is a conversion of a modern sound machine, has fixed speeds. The reason the silent speed is 18fps rather than 16 is, as I recall, that Kodak introduced this when they introduced Super 8, with the idea that the slightly higher speed would give better results for people adding sound to their silent films. I assume the single-system sound cameras introduced rather later were also 18 fps, tho Im not certain (I dont really do cameras). For some reason I wot not of, this speed change spread to 16mm. Incidentally, since the speed change on the Elf from which the Classic derives is by swapping a belt on a two-part pulley, one could if desired have a 16fps pulley. I understand Tony Reypert has done one or two like this (at extra cost, of course).

All this speed business is a bit irrelevant unless you are running your own silent films on Standard 8 or 16mm from long ago which were actually shot at 16fps. In the commercial cinema world, there appears to have been no such thing as a truly standardised silent speed. In the early days, it depended on the cranking speed of manually-operated cameras. Later, silent film speeds tended to increase, and by the end of the silent era speeds as high as 22fps were not uncommon. Before sound and the need for a fixed speed, it was common practice for cinemas to run films at a speed that suited the desired length of the programme, eg to increase the number of showings to increase takings. The other factor is our own perceptions. To us, films projected at 16fps can seem slow, with interminable titles, used as we are to a much faster cinematographic pace. 18fps partially addresses this without doing too much violence to the projected image. (You will recall the days when silent films on TV were run at 25fps to suit TV technology, giving speeded-up, jerky motion - OK maybe for the Keystone Cops, but horrid for, eg, Battleship Potemkin. And then they started doing stretch printing, repeating some frames to get lower apparent speed, but still producing an unnatural-looking motion). At the end of the day, it is down to individual preferences and individual films as to what looks right, but you do have to work within the technological constraints that conversion entails.


Q. Am I right in thinking that a sound projector, designed for the American 110 volts supply,
used on the UK mains via a step-down transformer, will run slow due to the difference in mains frequency?

A. Yes. Unless you change the pulley (see above)


Which 9.5 projector?

Q. If my main interest was collecting silent 9.5 films, what projector would you recommend? I would prefer to use a vintage machine rather than a modern conversion.

A. Definitely a "how long is a piece of string" question. We need to define our terms a bit to start with. When you say 9.5mm silent, I think we have to assume that that includes notched films. This is because some films are only available notched, but also because it is the notched prints that so often have that wonderful sharpness and clarity. And when you say conversion, I will assume you dont rule out things like lamp conversions but mean simply a projector designed ab initio to run 9.5. We will also assume you are not interested in "toy" projectors, in which class I place things like the Ace, Kid and Imp as well as the more obvious Bingoscope, Hunter or whatever.

So we are left with three basic options; the Baby, the Lux and the Bolex PA/DA. I think the Baby, fun tho it is, is too limited in lamp and lens terms, quite apart from being "stretched" from 30ft to 300ft rather than designed for it. At the other end, the Bolex, while capable of excellent light output, has the fatal flaw that it must be restarted after each notch, of which there may be several per title. This is just too distracting even for you, let alone an audience. So it comes down to the Lux but, of course, great care in selection is needed because of the Mazac disintegration that affects motor and gate. You really need to find the later YC model, which has a steel gate, because although motors can be replaced, its a lot more difficult to replace the gate. With a modern lamp and a better lens say an old-style B&H, which can be fitted to a bored-out lens sleeve and a modest screen size, the Lux will give good results. You could of course go mad and splash out on a Coq dOr, if you can find one. Among other features, it has the shutter between the lamp and the film, an immediate and substantial reduction in the amount of heat getting to the film without affecting the light on the screen. But dont go mad he who uses a too-powerful lamp and burns the titles of a notched film shall be cast into outer darkness and allowed to have only Std 8 films until his crimes are purged. But unless you are a keen and dedicated nerd, you run the risk of serious film damage because the Lux has no sprockets and, basically, that is just asking for trouble.

What the Lux will not help you with is the multi-reel silents like Metrollopis (with running titles), or the White Hell of Pitz Palu. You can do it on a Lux, but its a lot of changes. So you may want a second projector for such films. A Bolex with arms extended for 900/1000ft spools would cover both, but projectors are still so cheap, why not have two? As my partner says, a boy who knows how many projectors he has hasn't got enough projectors. Here your scope is much wider; as well as basically 9.5 silent machines like the 200B, Specto, Eumig P3, Gem et al, you can branch out into multi-gauge with the Heurtier Supertri or the Bolex G3, and of course all the sound projectors are there for you as well, tho you usually get a fixed silent speed with them. There are more esoteric machines like the Europ, but these are rare. My own choice is the Specto; you can have a 9.5/16 one if you feel like branching out - or maybe the Heurtier. But if you are like me, you will do your best to have all of them. My partner is quite right - a young friend on a visit once counted my projectors and found 48. I have to confess I panicked - 48 is such a pathetic number - and rushed off and bought half a dozen more (only then did I find two projectors missed in the original count!) and have not looked back since.