Some of the things I have been up to include a third, abortive, version of the sound unit, an attempt to make the sound optic move to and fro across the track on the flat, rather than by tilting as I have done up to now. It became onvious that this would require far more, and more accurate, work than I thought was worthwhile, so I stuck with version 2, ie using an L516 optic (I refuse to believe it is from a Son [ugh!], for obvious reasons).

I have re-located the pivot of the low sprung roller after the second sprocket.

      

I have fitted a 110v AC  to 12v DC power supply in the base for the computer fan on the side of the lamphouse. This is on whenever the projector is connected to 110v.

I have built and installed, in the space where the motor capacitor used to be, a 110v AC to 4v DC power supply for the exciter lamp. This thing cost me hours of effort and angst. As you know, I am no electronics expert and could do nothing right with this unit, building and re-building repeatedly, then having to bypass bits of the circuit board where I had destroyed the copper tracks. It was an absolute nightmare - it kept doing imposssible things like the trimmer pot  which was to set the output voltage reading from low (but not low enough) at one end of its travel, via a higher voltage in the middle, then back to the number it first thought of at the other end. I finally got it done after repeated exchanges with my experts. This and the fan supply are both connected via trailing leads with DC plugs. Must find a way to differentiate or I will blow up the exciter lamp.

I decided it was worth trying the effect of tightening the springs on the sound gate (ex L516 as you know). I did this and the film kept jumping out. I was beginning to despair and to fear I would have to come up with a totally different solution. However, I first tried adding a sprung rubber roller and, finally, I have halfway decent sound, with good adjustment of the optic à la Vox.

 I have done extensive other bits of fiddling, including boxing the power supply/ballast for an HID lamp and finding a way to connect it so that I can use the same unit for other projectors, changing both rollers on the top sprocket etc etc etc. I now have an even longer list of things to do to refine the sound and the physical performance of the machine. Which, if you are not careful, I shall share with you in due course.

As for the Rural Sonore, I have tried out various things. Here is a pic of a re-work of the lower sprocket film retainers; this I made several years ago.



The shape of the arms was I think dictated by some bits I had left over from an attempt to make a direct copy of the original. It works OK but reveals an area I always struggle with - spacial stuff and rotation of shapes and figuring out how a thing will work. In this case, the problem is the bottom roller. It was intended to act as a spring-loaded buffeer for the take-up. However, when loaded with film, it simply does not function, but acts as a fixed roller. I guess it's something to do with where the pivot is, so I may have to re-work this, tho' it works OK as it is.

I also finally got round to trying out the machine with the latest incarnation of the sound head. I realise that the framing could be changed by using the bit of slack in the fixing of the plate that carries the fixed front gate. This is separate from the part of the mech with the claw so moves the entire aperture, both fixed and sprung gates, in relation to the claw. This really makes my brain hurt. However, there is now some unsteadiness of the film in the gate, so clearly more work is needed. I have also done a bit of crude bending and stopped the aperture plate moving with vibration when the machine is running.The sound itself is much more promising. There's a fair bit wrong with it, but it sounds as tho it is fixable. I need to replace the switched mode power supply I have been using with a proper, regulated DC supply and do some more fiddling.

29th February

 Here is an update on the Rural Sonore. I fitted a 15v 150w dichroic mirror lamp (just using the same fitting as planned for the HID lamp) and found that, although there was light visible round the various joins, it was not substantial, due in part no doubt to the light being mostly reflected forward. The latest incarnation of the sound reader was a considerable improvement, tho' a long way from being good. A change of amplifier was part of the improvement; another change and the sound was actually approaching respectable. I have also installed the power supply for the HID into a metal box; the plan is connection via banana plug leads as I intend to use the same power supply for other projectors.

So much for the good news. Now that I have been running longer bits of film, a variety of issues have crope out from the woodwork. First off, the machine keeps losing the top or bottom loop, or both. I suspect this is due to a poor film retaining set-up on top and bottom sprockets. This will have to be corrected before I can examine other issues such as the sound head itself. Associated with this are various sound defects like warbling et al - hard to know if these are wholly loop-related or not at this stage. Also, volume is low, but my once-trusty pre-amp has let me down and does not improve the sound - level up, quality way down. Another problem is that both focus and the position of the aperture plate seem to be affected by vibration and so are drifting off. Framing is also off - I get a frame line at the top of the pic but there is no framing device (tho' I have seen cases where one has been fitted) nor any significant travel on the gate itself (unlike the Home Talkie).

One other issue. I found that the motor was being very lackadaisical about starting and getting up to speed, risking damage to the film. I therefore fited a separate lamp switch (for the 15v 150w supply, as the HID lamp will be switched separately). After discussion with a friend, I doubled up the capacitor and now it goes like a rocket. I still have some residual concern that this might damage the motor. Has anyone any experience or knowledge of this?

Here is the latest incarnation of the Rural Sonore sound reader.

     

26th Febtuary

Here are the pix of the fully assembled lamphouse, which I think are broadly self-explanatory. You are very privileged to see these pix befpre I have actually tested it out - it may leak light all over the place (Iknow I shall have to do more with the fan) and/or generally leave me with egg on my face.

                                              

Here are a few late  (Autumn 2020) additions to the pix above, showing the HID lamp in situ and revealing that the knob on the douser has changed.

          
25th February

I lost another week to another bug, but have since moved on a bit. I told you of my adventures with the sound reader on my Rural Sonore, but maybe not why I wanted it. More on that later. The last thing I told you was about my efforts to use a festoon lamp, with limited success. After much head-scratching with the tthing on and off the machine, I came to the conclusion that the problem lay with the Elf sound optic. I just could not get it to focus unless it was so close tothe film it fouled the sound gate, which has a raised lip. I also reverted to a standard exciter lamp. Luckily I had one that was insulated; most rely on the mech for the return path, on which keen I am not. I found an alterntive - it might be from a GBL516 or maye even a Son (ugh!). I'll do some pix for you. To avoid fouling the lamphouse, which tips back just like a Baby or an "H", I had to turn it thru 90 degrees, requiring a different lamp with a horizontal filament. The Elf telescope holder was nbg as the difference in size (my new one is a tad smaller) was too little to allow for a sleeve. So I had to machine a replacement from solid aluminium. I also put some rough shielding around the lamp to cut down on glare.

Back now to why I am pursuing this so determinedly. Your starter for 10 is this string of pix of a fairly innocent Rural Sonore lamphouse, which does not suspect what is about to hit it.

                    

Let me draw your attention to a couple of features. In pic 1, the notch at the top is where air from the motor fan comes in. Note the dividing wall to diect some air to the lamp and some across the gate to cool the film - another example of the superb design of the Rural. The lamp, incidentally, is a standard Vox lamp of 15v 200w. The lamphouse is pretty shallow; I have re-painted the cover, which simply slides off. Pic 2 is just a general view of the inside. Pic 3 shows past interference, probably to do with the conversion to 16mm during the war.You can see that the bracket on which the lamphouse pivots (see pic 2 for a different angle) is attached to the body by 2 screws. You can also see where it originally sat as an integral part of the main casting, to the right of that enlarged hole in the base. The front view in pic 5 shows how air is channeled across the gate. Pic 6 shows an important (to me) feature in the shape of a threaded hole. This is a relic of the earliest days of the Rural silent. On here pivoted a 2 stage douser - 1st part gauze for still, second part solid for full cut-off. A cycle-type cabe led from this thru the bottom of the lamphouse and round to a lever on the main shaft of the mech, just behind the pulley taking the drive from the motor. This originally pushed the drive pulley forwards, disengaging a dog clutch, with the pulley free to turn without driving the mech, to allow a still picture to be shown, while at the same time pulling the dowser into place. This mech had been disabled on my silent Rural and it is easy to see one possible reason why - how can you move the shutter out of the way with no means of turning the mech?

OK. I explained to you the problems I had trying to get the original sound reader to work, but I daresay I could have made it work. However, what I wanted to do was fit one of the discharge lamps described by Tony Saffrey in an article about a Specto in Group 9.5 mag, with the necessary douser, hence my long digression above. I have seen these lamps in use - they seem able, in some cases anyway, to outshine even a conventional Xenon. But this really requires a separate exciter lamp - I don't fancy scraping bits off the morror of a lamp costing £60 plus. However, this lamp is also deeper fron to back than can be fitted in the lamphouse I have shown you above. So I needed to find a way to extend the lamphouse, fit a cooling fan for when the motor is not running and fit a douser and a separate exciter lamp - all without making any new holes or other permanent alterations to the machine. This may be a personal foible, but I think there is a strong case to be made for keeping projectors as near to original as possible.

So now I have to go and re-assemble all the bits I have removed to show you where I started and do more pix.