Also, the set has a bias cell which I hope to rejuvinate, but wonder if the set should work without it. (I have -1.3 volts bias on the grid of the 6Q7 without it in the circuit.)
Finally, the tuning eye tube does not light up even though the filament is good...any idea what might be wrong with the tuning eye?
Would appreciate comments on each of these 3 questions.
Thanks
1. Distortion is usually caused by leaky coupling caps in the audio circuit. Your phase inverter circuit may well be a problem. In your circuit there is a resistor network in the grid circuit. Are these values close? This radio has a direct coupled audio output circuit. Check 6AC5's and 6P5's. You can try 6J5 for 6P5.
2. Jump across the bias cell if you don't rejuvinate the battery. You will notice no difference in operation. Don't leave the grid circuit open or with a dead cell.
3. This radio uses a 6U5 eye tube. Often they become weak and lose green color. If pin #4 has around 225 volts and filaments are lit with no green showing the tube is bad. They are expensive. You may want to consider 6E5 (more sensitive) or 6AB5 (lighter filament).
Norm
:I have a Sears model R301 10 tuber..it has a push pull output stage driven by a pair of 6P5 Drivers and one phase changer...I have recapped most of the caps, and have good B+ everywhere except it is high (165 vs 100V) at the Plate of the phase changer.
:It has poor reception (many need an alignment) and the few strong stations that do come in are distorted. Not sure what the problem is but wonder if the high B+ on the phase changer could be causing the distortion?
:
:Also, the set has a bias cell which I hope to rejuvinate, but wonder if the set should work without it. (I have -1.3 volts bias on the grid of the 6Q7 without it in the circuit.)
:
:Finally, the tuning eye tube does not light up even though the filament is good...any idea what might be wrong with the tuning eye?
:
:Would appreciate comments on each of these 3 questions.
:Thanks