02-20-2014, 07:06 PM
Well, I found the mistake on my schematic and corrected it below.
[Image: http://www.philcoradio.com/images/phorum...p_Rev1.jpg]
Yes, boys and girls, B+ is fed through R19 and R20, both 8.2K 1/2 watt resistors, to the collectors of Q1 and Q2, and to the bases of Q5 and Q6. The same source also has a 120 ohm, 2 watt resistor (added in the revised schematic above) which feeds the emitters of Q5 and Q6 through 560 ohm, 3 watt resistors.
It will take some time to trace out the power supply and convert it into schematic form. But I can assure you that from the volume controls through the audio circuit, including the power supply lines, this schematic is now correct. The audio amplifier control board above the audio output circuitry may or may not match the 4400 - I haven't gone that far yet.
Now, I'll go back and measure the B+ source (labeled To Power Supply in the revised schematic above) to see what that voltage is, just for fun.
[Image: http://www.philcoradio.com/images/phorum...p_Rev1.jpg]
Yes, boys and girls, B+ is fed through R19 and R20, both 8.2K 1/2 watt resistors, to the collectors of Q1 and Q2, and to the bases of Q5 and Q6. The same source also has a 120 ohm, 2 watt resistor (added in the revised schematic above) which feeds the emitters of Q5 and Q6 through 560 ohm, 3 watt resistors.
It will take some time to trace out the power supply and convert it into schematic form. But I can assure you that from the volume controls through the audio circuit, including the power supply lines, this schematic is now correct. The audio amplifier control board above the audio output circuitry may or may not match the 4400 - I haven't gone that far yet.
Now, I'll go back and measure the B+ source (labeled To Power Supply in the revised schematic above) to see what that voltage is, just for fun.
--
Ron Ramirez
Ferdinand IN
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