37-611 variation - Printable Version

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+--- Thread: 37-611 variation (/showthread.php?tid=12962)

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37-611 variation - thinktreasure - 08-21-2015

I've started work on restoring a 37-611.

I need to locate a schematic for the version I have.

It's setup differently than the common schematics I have found.
It uses the same tubes but the chassis  layout is a bit different.
There are 3 bakelite caps instead of 2. Plus the electrolytic caps are marked differently along with a change in the power supply.

There are 2 "flexible"  resistors, one is definitely open, according to the schematic I have, I think it's suppose to be 400ohms and feeds the cathode of the output.

This would be a lot easier if I could find the variation of the schematic that applies to this chassis.
Otherwise, it will require a lot of tracing wires. And ignoring component markings.

i also will have to trace the connections on the bakelite to figure out what the caps are suppose to be inside it, assuming it wasn't a change added.

The other flexible or possibly fuse able resistor between the 2 main filters measures 38 ohms, and the only other resistor of it's type listed on the schematic I have is 20 ohms. ( has it changed value or was it changed by the factory?)

Another thing. One of the electrolytic can  terminals is marked with paint -RED paint , Yellow paint , and none.
According the the values on the cap- RED is Common? Yellow, and No paint are the cap sections?
This is normal for philco radios of the time?


Anyone out there have variations on the schematic for this model? 37-611

What should be used to at least replace that one flexible resistor (wattage) I know is bad.


I removed the covering on the flexible resistor to verify what it was and that it is open.

See attached picture and drawing on schematic showing  that area

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RE: 37-611 variation - klondike98 - 08-21-2015

Check the changes in the changes.zip file that Ron posted here http://www.philcoradio.com/phorum/showthread.php?tid=215

Maybe that has some info.

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RE: 37-611 variation - Bob Andersen - 08-21-2015

The changes document shows that the 0.01 mfd cap on he RF chassis (#19) was changed to a 4989-DU bakelite bloc. It has two 0.09 mfd caps inside.

Checkout the 4989-ODU to see how the caps are wired inside.

http://www.philcorepairbench.com/bblokcap.htm

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RE: 37-611 variation - thinktreasure - 08-22-2015

Thank You
I looked that document over twice but stopped at the first grouping of models in that sequence and never saw that.
Thanks for looking it over
Obviously this is at least run #4 of this chassis.
Also thank you for that cap chart!
Finally it makes a bit of sense.

I guess they never issued revised schematics and chassis diagrams just a printed change sheet.

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