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model 20 hum (detector circuit?)
#57

I need the correct voltages from a working Philco Model 20 or 21 for the 24 detector tube and the 27 audio tube. I have the readings from the literature, however these were taken in the days when meters were only 10K ohms per volt. I am using a digital meter.

I know the correct filament voltages as well as the cathode voltages, however because of a problem I am having I need the other voltages. Also I would like to know what readings you measure at point B, D, E, F, G and J. I have a good idea of the correct voltages, but I don't want to guess on this one.

Any help would be most appreciated. However I don't want to guess or use the voltage readings from a tube manual or the Riders or Philco literature.

Someone had suggested to load the DMM with a resistor, however that won't work because the impedance of the new Fluke is, according to Fluke, infinite..


Messages In This Thread
model 20 hum (detector circuit?) - by Tubesforme - 10-19-2015, 01:11 PM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-19-2015, 06:23 PM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-20-2015, 10:01 AM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-25-2015, 10:57 AM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-25-2015, 11:39 AM
RE: model 20 hum (detector circuit?) - by morzh - 10-25-2015, 11:08 PM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-26-2015, 10:18 AM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-26-2015, 10:34 AM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-26-2015, 11:24 AM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-27-2015, 08:43 PM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-28-2015, 11:52 AM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-28-2015, 03:36 PM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-30-2015, 06:13 PM
RE: model 20 hum (detector circuit?) - by OZ4 - 10-31-2015, 10:40 AM
RE: Low continual hum in model 21 - by Tubesforme - 10-23-2015, 11:19 PM
Need correct voltages for det and af model 20 - by Tubesforme - 11-07-2015, 05:54 PM



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