Elmo 1200 and 1200-HD Projectors

Post by **Lunar07** » Thu Aug 19, 2004 1:52 am

What is the difference between the Elmo 1200 and Elmo 1200-HD projectors? Which one has the 1/F switch?
I checked the Elmo 1200-HD manual and it seems it has an R-1 Synch Jack. Is this the same as a 1/F switch or does it use a different pulse system?

pelluet · Post by **pelluet** » Thu Aug 19, 2004 8:27 pm

It might be worth asking this question again over on the collectors forum; http://8mmforum.film-tech.com/ there are lots of Elmo experts over there.

However, if it's any help, you will find the socket on the Elmo ST 1200 that is used to connect it up to the R-1 interface is on its own on the front of the projector just below the lens. But remember, this only sends a pulse signal to the R-1 and isn't designed to regulate the speed of the projector.

Mike

Post by **Lunar07** » Fri Aug 20, 2004 12:24 am

pelluet wrote:It might be worth asking this question again over on the collectors forum; http://8mmforum.film-tech.com/ there are lots of Elmo experts over there.

Thanks!

However, if it's any help, you will find the socket on the Elmo ST 1200 that is used to connect it up to the R-1 interface is on its own on the front of the projector just below the lens. But remember, this only sends a pulse signal to the R-1 and isn't designed to regulate the speed of the projector.

I am aware that this does not regulate the speed of the projector. But the Elmo ST 1200 have the R-1 Synch jack too like the ST 1200 HD? I wonder what is the difference between the 1200 and 1200-HD? Also, I heard that one of these models have the 1/F switch. I wonder if the R-1 switch acts as an 1/F switched pulse.

On this note: What is the characteristic of the 1/F pulse as compared to Pilotone pulse for example? And how can these be measured to determine type of pulse?

Post by **wallnuts** » Mon Aug 23, 2004 1:58 am

I have an Elmo ST1200 HD. It has a sync socket. The socket is indeed a 1/F switch. The pulse is in the shape of a square wave. Although its not a clean signal because the contacts are opening and closing so fast. Had Elmo only used a Hall effect sensor instead it would have been a lot cleaner. I can post a digital waveform from my ocilloscope on here but it will take me some time since I did not save them. The signal is a solid 24hz when the speed is selected at 24 frames per sec. And is 18hz when at 18 frames per second. It runs a little faster, about 1% without film through the gate, but is remarkably stable! After all, the ST1200HD was intended for this application. I use this signal with the Film Groups digital to pilotone converter and my Nagra 4.2 with the QSLI resolver built into it. The Nagra compares the signal change between the projector and what was recorded onto the tape from the camera. The Nagra then varies its speed by itself. The whole system works quite well as long as you have good belts in your projector!!

Andy

Post by **monobath** » Mon Aug 23, 2004 2:35 am

And if you don't have good belts, you can make 'em yourself with green polycord from http://www.smallparts.com/ I made a new belt for my Elmo ST800 with polycord, and it works great.

Are there any other sources for good used Elmo ST1200 or GS1200 projectors besides Ebay? Also, what is the difference between the ST and GS versions? Finally, what is a 1F switch?

Thanks.

Post by **Lunar07** » Mon Aug 23, 2004 2:47 am

So the R-1 jack is equivalent to a 1/F pulse. I used to do what you describe below with a Bauer Royal projector that had a 1/F switch built into it and connected to the Super8 Sound recorder that can resolve 1/F pulses. The projector failed and was of no use later.

I can see here that one can record sound to a PC while running this setup. But how could one telecine at 24FPS without problems while running this setup? So that everything stays in perfect synch. hmmmmmmmm........

wallnuts wrote:I have an Elmo ST1200 HD. It has a sync socket. The socket is indeed a 1/F switch. The pulse is in the shape of a square wave. Although its not a clean signal because the contacts are opening and closing so fast. Had Elmo only used a Hall effect sensor instead it would have been a lot cleaner. I can post a digital waveform from my ocilloscope on here but it will take me some time since I did not save them. The signal is a solid 24hz when the speed is selected at 24 frames per sec. And is 18hz when at 18 frames per second. It runs a little faster, about 1% without film through the gate, but is remarkably stable! After all, the ST1200HD was intended for this application. I use this signal with the Film Groups digital to pilotone converter and my Nagra 4.2 with the QSLI resolver built into it. The Nagra compares the signal change between the projector and what was recorded onto the tape from the camera. The Nagra then varies its speed by itself. The whole system works quite well as long as you have good belts in your projector!!

Andy

Post by **filmbuff** » Mon Aug 23, 2004 4:05 am

Lunar07 wrote: But the Elmo ST 1200 have the R-1 Synch jack too like the ST 1200 HD? I wonder what is the difference between the 1200 and 1200-HD? Also, I heard that one of these models have the 1/F switch. I wonder if the R-1 switch acts as an 1/F switched pulse.

There are 3 versions, the ST-1200, ST-1200D, ST-1200HD. The HD model is the only one with 2 track mono recording. The D and HD have a frame counter. Some ST-1200(D?) projectors do not have the R-1 jack. Always make sure it does if that is important. I use to have a D and an HD and they both had the R-1 jack but I've seen a few plain 1200's without it.

Post by **Lunar07** » Mon Aug 23, 2004 4:28 am

monobath wrote:And if you don't have good belts, you can make 'em yourself with green polycord from http://www.smallparts.com/ I made a new belt for my Elmo ST800 with polycord, and it works great.

Are there any other sources for good used Elmo ST1200 or GS1200 projectors besides Ebay? Also, what is the difference between the ST and GS versions? Finally, what is a 1F switch?

Thanks.

The 1/F switch is the PC switch (flash socket) you see on many many super 8 cameras. It sends one pulse per frame. This pulse can be used instead of the pilotone frequency for synching purposes. The 1/F pulse is refered to as Digitone. Of course, the synch recorder and the audio resolver must be capable of using such a signal The Super8 Sound recorder was such a recorder.