Bell & Howell

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cmoore
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Bell & Howell

Post by cmoore »

Are B&H schems commonly available.?
Looking for a Filmosound 138 M-2.

Anybody know where i can get one.?
I have found a few, but not this model
Thank You
Stevem
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Re: Bell & Howell

Post by Stevem »

There very simple tube circuits, what's the issue with it?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!

Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
sluckey
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Re: Bell & Howell

Post by sluckey »

Here you go. Turn to page 95...
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cmoore
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Re: Bell & Howell

Post by cmoore »

Just making sure i abandoned all the stuff for the audio reader. :)
Thanks for the great link
sluckey
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Re: Bell & Howell

Post by sluckey »

That filmosound pdf is worth saving. I have extracted and stitched the 138-M schematic together for quicker access.
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cmoore
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Re: Bell & Howell

Post by cmoore »

sluckey wrote: Fri Jun 14, 2024 4:45 pm That filmosound pdf is worth saving. I have extracted and stitched the 138-M schematic together for quicker access.
Thank..... YOU :)
cmoore
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Re: Bell & Howell

Post by cmoore »

Stevem wrote: Fri Jun 14, 2024 9:59 am There very simple tube circuits, what's the issue with it?
Yes.... thanks.
Stuff is really CRAMMED in here.
I was thinking the audio amplifying part could probably be used as is for starts, so i was trying not to pull it all out and start over, unless i saw something really strange........ 1M grid stops and 68k grid leaks. :)
Thanks again for your help.
cmoore
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Re: Bell & Howell

Post by cmoore »

sluckey wrote: Fri Jun 14, 2024 3:13 pm Here you go. Turn to page 95...
I must have spent an hour on Yahoo looking for this stuff.
Maybe i overlooked it, or i use the wrong words for a search.
Anyway...... A big THANKS to you as well :D
maxkracht
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Re: Bell & Howell

Post by maxkracht »

I wouldn't trust too much in there. Playing on a current limiter and/or lowering the fuse to 1A might be a good idea. I don't think the giant, hermetically sealed, steel electrolytic cans visibly leak but they do go bad. Same with most of the coupling caps. I always start over on B&H stuff, aside from the standalone power amps that aren't so crowded inside.
sluckey
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Re: Bell & Howell

Post by sluckey »

cmoore wrote: Fri Jun 14, 2024 6:25 pm I must have spent an hour on Yahoo looking for this stuff.
I got lucky. Just did a search for "filmosound" on Hoffman's forum and quickly turned up this topic with the web link for that pdf.

https://el34world.com/Forum/index.php?t ... 4#msg47394
cmoore
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Re: Bell & Howell

Post by cmoore »

maxkracht wrote: Fri Jun 14, 2024 6:29 pm I wouldn't trust too much in there. Playing on a current limiter and/or lowering the fuse to 1A might be a good idea. I don't think the giant, hermetically sealed, steel electrolytic cans visibly leak but they do go bad. Same with most of the coupling caps. I always start over on B&H stuff, aside from the standalone power amps that aren't so crowded inside.
Yeah, it is a mess in there.
The chassis is about 10x4 inches and just packed with stuff.
Would be better to just gut it and build something simple.
It is a single 6l6.
It is a metal case 6L6, i am assuming one of the earliest iterations with the lower power dissipation
Stevem
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Re: Bell & Howell

Post by Stevem »

Yes, those only had a 19 watt rated plate and said to be good only up to 360 volts and 270 or so on the screen.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!

Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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LOUDthud
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Re: Bell & Howell

Post by LOUDthud »

Note that the 6L6 {nothing} has the metal shell connected to pin 1 on the socket. Don't use that socket terminal as a tie-point, ground it so you don't create a shock hazard.
cmoore
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Re: Bell & Howell

Post by cmoore »

LOUDthud wrote: Sat Jun 15, 2024 2:20 pm Note that the 6L6 {nothing} has the metal shell connected to pin 1 on the socket. Don't use that socket terminal as a tie-point, ground it so you don't create a shock hazard.
I got the projector, speaker cab and some 16mm movies at a garage sale for 40 USD.
Had i known more..... or anything ..... about these amps i may not have bought it.
I thought it was a 2x 6V6 with a AlNiCo speaker.
It has a fiield coil speaker, not even sure if it is good, or good for guitar.
So i am just going to gut this thing, and measure the OT to see what it really is.
I have not checked the DCR of the speaker, but that may not tell the whole tale of the OT.
This will be more work than anticipated.
The speaker cab IS Pretty Cool though :)
maxkracht
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Re: Bell & Howell

Post by maxkracht »

As long as the paper isn't too rotten there's a good chance the speaker is still fine. I doubt anyone was abusing it too much. $40 and a few hours work for a funky looking Champ isn't bad. If you take the amp apart, be careful with solvents around the paint. Seems like anything more than soapy water will take the paint off and there's always some mystery
1940's goo that will also remove the paint. Just leave the goo alone unless you plan to refinish.
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