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6V6 amp from Bell & Howell DES 385 projector
8/23/2003 5:16:33 PMJ-F
Hi! I have a tube amp from a Bell & Howell projector (DES 385). But first, I have not the schematic and second, there is some parts that I don't know!

There is a mini 9 pin socket mount on rubber spacers with "5879" writen near. Look like a tube but there is a shield on it. I can't see and I can't remove. There is also a look like tube mount on an octal socket with "P.E.C." write on it. What are these parts? And why there is 3 6v6, not 2? Is it because there is 2 plugs for single and dual speakers?

Tubes list: 5y3gt, 3x 6v6, 2x 12ax7. Only a micro input.

Thanks for any help!
J-F

8/23/2003 9:41:55 PMNorm Leal
Hi J-F

You might have one 6V6 driving a pair in push-pull. This was done by manufacturers of some better radios.

A 5879 is a good low noise pentode tube. It's often used as a preamplifier. The projector most likely also had a photo tube. This photo tube looks at a line on the film for sound. The 5879 was probably used as amplifier after the photo tube? P.E.C. might have been the photo tube?

Norm


:Hi! I have a tube amp from a Bell & Howell projector (DES 385). But first, I have not the schematic and second, there is some parts that I don't know!
:
:There is a mini 9 pin socket mount on rubber spacers with "5879" writen near. Look like a tube but there is a shield on it. I can't see and I can't remove. There is also a look like tube mount on an octal socket with "P.E.C." write on it. What are these parts? And why there is 3 6v6, not 2? Is it because there is 2 plugs for single and dual speakers?
:
:Tubes list: 5y3gt, 3x 6v6, 2x 12ax7. Only a micro input.
:
:Thanks for any help!
:J-F

8/24/2003 5:25:34 PMJ-F
Hi Norm!

Wow it's weird! Someone said to me that this 6V6 may be a rectifier! Is it possible? I did not check wiring, so I really don't know. For the PEC tube, it can be a photo tube. It's a glass tube with a metal enveloppe and also a window. In this window, I can see a beige curve plate. In the middle, there is a big pin with a look like getter on it. But I don't understand what you mean for it's utility... Is it use like a clock? It search for pics and black line between pics??? Is it what you mean?

Thank you!
J-F


:Hi J-F
:
: You might have one 6V6 driving a pair in push-pull. This was done by manufacturers of some better radios.
:
: A 5879 is a good low noise pentode tube. It's often used as a preamplifier. The projector most likely also had a photo tube. This photo tube looks at a line on the film for sound. The 5879 was probably used as amplifier after the photo tube? P.E.C. might have been the photo tube?
:
:Norm
:
:
::Hi! I have a tube amp from a Bell & Howell projector (DES 385). But first, I have not the schematic and second, there is some parts that I don't know!
::
::There is a mini 9 pin socket mount on rubber spacers with "5879" writen near. Look like a tube but there is a shield on it. I can't see and I can't remove. There is also a look like tube mount on an octal socket with "P.E.C." write on it. What are these parts? And why there is 3 6v6, not 2? Is it because there is 2 plugs for single and dual speakers?
::
::Tubes list: 5y3gt, 3x 6v6, 2x 12ax7. Only a micro input.
::
::Thanks for any help!
::J-F

8/24/2003 7:43:35 PMNorm Leal
Hi J-F

Your 5Y3 is the rectifier.

You have a photo tube. Film has a line down one edge that varies as people talk. Light shines on this line through the film and is picked up by a photo cell. This signal is then amplified.

Here is a test if you have a Simpson 260 or other meter with high voltage battery, 15-30 volts will work. Put your meter on the highest ohms scale. Find two leads on the photo cell that reads a little. Shine light on the photo cell, resistance will go down. It won't read a lot but you will notice the difference.

Norm

:Hi Norm!
:
:Wow it's weird! Someone said to me that this 6V6 may be a rectifier! Is it possible? I did not check wiring, so I really don't know. For the PEC tube, it can be a photo tube. It's a glass tube with a metal enveloppe and also a window. In this window, I can see a beige curve plate. In the middle, there is a big pin with a look like getter on it. But I don't understand what you mean for it's utility... Is it use like a clock? It search for pics and black line between pics??? Is it what you mean?
:
:Thank you!
:J-F
:
:
::Hi J-F
::
:: You might have one 6V6 driving a pair in push-pull. This was done by manufacturers of some better radios.
::
:: A 5879 is a good low noise pentode tube. It's often used as a preamplifier. The projector most likely also had a photo tube. This photo tube looks at a line on the film for sound. The 5879 was probably used as amplifier after the photo tube? P.E.C. might have been the photo tube?
::
::Norm
::
::
:::Hi! I have a tube amp from a Bell & Howell projector (DES 385). But first, I have not the schematic and second, there is some parts that I don't know!
:::
:::There is a mini 9 pin socket mount on rubber spacers with "5879" writen near. Look like a tube but there is a shield on it. I can't see and I can't remove. There is also a look like tube mount on an octal socket with "P.E.C." write on it. What are these parts? And why there is 3 6v6, not 2? Is it because there is 2 plugs for single and dual speakers?
:::
:::Tubes list: 5y3gt, 3x 6v6, 2x 12ax7. Only a micro input.
:::
:::Thanks for any help!
:::J-F



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