10-26-2021, 09:18 PM
I just made some measurements.
With good volume
RF AVC grid voltage = -1.1
IF AVC grid voltage = -0.56
When volume drops, the voltages get less negative which should boost gain.
RF AVC grid voltage = -0.7
IF AVC grid voltage = -0.23
So it seems gain is being lost somewhere in the RF/IF front end and the detector/AVC circuitry is working properly.
With good volume
RF AVC grid voltage = -1.1
IF AVC grid voltage = -0.56
When volume drops, the voltages get less negative which should boost gain.
RF AVC grid voltage = -0.7
IF AVC grid voltage = -0.23
So it seems gain is being lost somewhere in the RF/IF front end and the detector/AVC circuitry is working properly.