06-27-2026, 11:51 AM
Regarding the configuration of the the multi-tapped resistor in model 91 code 221 download and look at resistor 46A in the schematic from Nostalgia Air:
https://www.nostalgiaair.org/pdfs/Philco...DE-221.pdf
You will see two resistor section, 205 ohms between terminals 4 and 5; 95 ohms between terminals 3 and 4, terminal 3 going to chassis ground. The 136 ohm resistor is between terminals 1 and 2 but is not depicted in the schematic, an example of Philco's deficient documentation.
As I stated before I connected the 136 ohm resistor from the negative terminals of the B+ supply filter capacitor to terminal 4 on 46A. That gets the various voltages to the ostensibly correct values as disclosed in the voltage table below the circuitry schematic. The audio output to the speaker pair is working correctly.
I would call this to be a case of user engineering.
I think my problem is resolved. I'm moving on to alignment now. Thank you for your inputs.
LF
https://www.nostalgiaair.org/pdfs/Philco...DE-221.pdf
You will see two resistor section, 205 ohms between terminals 4 and 5; 95 ohms between terminals 3 and 4, terminal 3 going to chassis ground. The 136 ohm resistor is between terminals 1 and 2 but is not depicted in the schematic, an example of Philco's deficient documentation.
As I stated before I connected the 136 ohm resistor from the negative terminals of the B+ supply filter capacitor to terminal 4 on 46A. That gets the various voltages to the ostensibly correct values as disclosed in the voltage table below the circuitry schematic. The audio output to the speaker pair is working correctly.
I would call this to be a case of user engineering.
I think my problem is resolved. I'm moving on to alignment now. Thank you for your inputs.
LF
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