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Old 31st Oct 2019, 4:52 pm   #33
ms660
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Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 9,500
Default Re: Vintage Radio and Phonograph cutter schematic

The problem is there's no consistency in the various schematics and voltage tables etc some were measured with a 1k ohm per volt meter, some with a 20k ohm per volt meter, the difference between the two would make for different readings when comparing what your readings are, all I can suggest is to ascertain the original nominal value of the anode and screen grid resistors which are fitted in your unit and check them for unusually high or low resistance and replace as required, as for capacitors, treat all with suspicion.

I would leave the Y Class disconnected and the chassis earthed for the moment for troubleshooting purposes.

Does the radio receiver work? V1 and V2 voltages seem reasonable, V3 and V4 aren't used when switched to radio so far as I can make out.

Lawrence.
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