10W amp for bell & howell 16mm projector

Hey, I scored 2 Bell & Howell 16mm projectors out of the classifieds lasts week. The guy who owned them originally worked for some kind of training/education division of GM. I have a giant box of film featuring planes, tanks, assembly lines, weird laboratory scenes and stuff. They project fine but no sound. One has a '10 watt' amp. It is a little bit older. The other is a '15 watt' amp. slightly newer. The film transports(?) are the same though. It's the FILMOSOUND projector I think. Anyway, does anybody know of a place online to get info about these guys? I did a quick google search and came up with nothing... just some people swaping/selling film. I think between the two projectors I can get one working pretty well. Incase the data / schematics are not available will somebody at least help me read the cap values that are in it. They're flat rectangle looking things...axial leads... and the coding on them sort of makes them look like dominos... I think there are 6 dots on them with different colors. I'm confused. :?

joe

I had the 10W Filmosound.... Nothing special about the sound - - was actually kinda noisy with a little bit of a narrow freq. response. If you're a guitar player it might be just right for you though.

The route I'd take if I hadn't sold it would be to trace the circuits and do somewhat of a re-design. Upgrade the components and circuit a little bit.

Are you interested just in the amps, or do you want to make the projectors work to show your sound films? I may be able to turn up some info when I get into work on Monday. I work for a college and I have a lot of older A/V manuals, and that kind of stuff. I'm not sure I have any 16mm projector manuals from the tube era (which I assume from your description of the caps, is what you're looking at), but I'll see what I can find.

yeah... it uses a few odd tubes... or at least ones i havn't seen before. depending on the price, i'll probably buy all new tubes for it. I can deal with the audio side of it OK. However the weird optical soundtrack to electrical conversion i'm not sure about. this will probably sit in a cardboard box for a while. i've got a ton of crap to catch up on right now. figured i'd ask though.

joe

oh....yeah..... I had no intention of gutting it just to use the amps, I just wanted to get it working so I can get wasted with my friends and watch STD scare films or whatever.

A lot of those projectors had tubes on a crude (by todays standards) double sided Printed circuit board. These were prone to cracks and intermittent joints. Carefully examine the boards.

No sound, check the exciter lamps. The film goes through the gate behind the lens, and then around a freely rotating drum that has a small light outside and a photocell inside. No little light, no sound.

This of course assume you have optical sound and an optical sound projector. If you are trying to play mag-audio film on an optical-audio projector, you are going to have to get very stoned to hear anything good. Optical sound has a little wiggle-wave track along the side of the images. Mag-sound films have a thin stripe of black oxide painted on.

The domino caps rarely go bad and are of fine quality. There's a decoder chart somewhere but I'd leave them alone.

> Bell & Howell 16mm projectors ... the FILMOSOUND

You are going to have to do better than that: Hell&Bowell used the "FilmoSound" model name on millions of projectors over several decades. Get a model number and Google it.

> They project fine but no sound

You better do better than that too. What is "no sound"? Is there hum and hiss in the speaker? A little or a lot? Is it plugged in and turned on? Turned-up? Have you fiddled the switches?

Be careful with old film. 16mm is almost universally Safety Stock, not raw nitrocellulose, so it shouldn't explode, but keep it away from heat and flame and keep it in the can/box when not projecting.

You should contact GM's corporate archivist, and see if they want these films when you get bored. Probably they already have copies, though corporate archives have odd gaps (AT&T didn't keep the first unix machine), but they might want spares. However, dang if I can find GM's archives... contact Henry's group at http://www.hfmgv.org/ because they are in the same racket and will know who to contact.

Yeah the exciter lamps work. But I'm not sure if the photo-cell detection gizmo is doing its thing as it should. It does make noise. When it is running and you turn up the volume you hear nasty 60hz / 120hz Either because of poor/leaky filtering in the amp or EMI from the motor. I'm assuming the motors in these ran off of 117V 60hz AC... The film is threaded correctly around the soundhead. In High School and my 1st year of college I worked for an independent movie theatre wrestling with a bunch of junky 35mm projectors. So I have a little experience. But that doesn't really apply to the little 16mm filmosound. Other than maybe threading it up.

I'm not sure about the model. the only thing i can remember is 'filmosound'. i'll check into later.

joe

Yeah the exciter lamps work. But I'm not sure if the photo-cell detection gizmo is doing its thing as it should. It does make noise. When it is running and you turn up the volume you hear nasty 60hz / 120hz Either because of poor/leaky filtering in the amp or EMI from the motor. I'm assuming the motors in these ran off of 117V 60hz AC... The film is threaded correctly around the soundhead. In High School and my 1st year of college I worked for an independent movie theatre wrestling with a bunch of junky 35mm projectors. So I have a little experience. But that doesn't really apply to the little 16mm filmosound. Other than maybe threading it up.

I'm not sure about the model. the only thing i can remember is 'filmosound'. i'll check into later.

joe

double posting???? i got a few odd error messages.... i guess stuff is OK now.

oops.

I took a look, and while I don't have any paper manual for B&H (only Graflex and Kodak), I knew I had a link to some movie projector info on my work computer:

http://www.film-tech.com/cgi-bin/externallink.cgi?http://www.film-tech.com/warehouse/index.php?category=2;rt=1132595414404

Just click on the "manuals" button to the left, then on "16mm projectors" (or scroll to the bottom of the page) and you'll find a LOT of projector service manual pdf's for download, including many B&H models. Hope this helps.

thanks

one of them is either a 302 or a 8302. It is in worse shape. it looks to be slightly newer. The older looking one I have is in better shape. very similar. same film transport from what i can tell. different amp. My connection at work is kind of slow. I'll check out that link later on tonight when I can really download a few of those PDF's.