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Hi all. I am restoring one of these. I can't find a schematic for run 126 anywhere. Some parts (i.e. the dual wirewound power resistor part number 33-3436-2) are not identified. Does anyone know the proper values for each section of this resistor? Better yet, does anyone have a schematic for run 126? Thanks to all!
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Have you looked at the resource list:
http://www.philcoradio.com/resourceb.htm - there are a number of sources listed for schematics of various Philco models. One of them should have what you want. I assume you have looked at the Nostalgia Air 46-1201 code 121 schematic information? Incidentally, Philco used code numbers but did not use run numbers.
Others may be able to point you to schematic(s) and parts lists more compatible with your specific unit. There were production changes that were released through bulletins to dealers and service agencies and Riders and Beitmans publications do cover various production changes by manufacturers in their books, but finding the changes for a given model can be rather daunting.
Joe
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I found a schematic for a 46-1203. The circuit seems to be identical to the 46-1201 except for the addition of a 7C7 RF amplifier tube. The power resistor (R2) is a 50 ohm/120 ohm. Both units use a 50X6 rectifier. My 46-1201 power resistor has (measured) values of 41 ohms/68 ohms. Can anyone explain the purpose of these resistors? What effect would raising or lowering the values have? By the way, after the recap and alignment check, the radio works ok for an AA5. However, before i move on the something else (i.e. the turntable) I want to make sure the power resistors are right.
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Mstamper,
good news for you is, if a wirewound resistor is not open, it will be right where it should be value-wise, they do not drift.
Carbon ones do.
So if it is 50/120 ohms, this is what should be there.
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A power resistor or B/C voltage resistor reduces or resists the voltage as to drop it to the level/voltage needed.
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I believe that you meant that this was a 46-1201 Code 126, not a run 126, the run numbers were stamped on the chassis and I've never seen one higher then Run 4. I think I may have the info for a 46-1201 code 126, the code numbers on the 46-1201 ran from 121-128, probable more then I have heard of for any other Philco model. In spite of the model number they were not all made in 1946, they made 46-1201s until 1948 then updated the circuit to employ a higher B+ voltage.
Regards
Arran
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If Arran doesn't have the code 126 info, check with Chuck Schwark at
http://www.philcorepairbench.com/schematics.htm . Only a few bucks for good schematic and changes info.
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Some helpful info here:
http://philcoradio.com/phorum/showthread.php?tid=215
Look for the file "46-1201.zip" which includes many production changes to the 46-1201.
--
Ron Ramirez
Ferdinand IN