16-10-2015, 03:32 PM
I noticed some odd points of interest with my GEC and Ultra radios.
The GEC radio I have, for example, doesn't seem to run an AVG line from the AVG diode. The schematic shows it and the cathode taken to chassis potential. The AVG is then taken from another 1 Meg resistor that follows the volume potentiometer in series, being taken to the Mixer grid and IF tube grid. Or maybe I'm missing something? So far as I'm aware from the Chas Miller book it's more normal to take the IF amplifier to the AVG diode with a set bias resistor. I'll have to look at it again and see the logic behind it.
The HMV seems more orthodox.
The GEC radio I have, for example, doesn't seem to run an AVG line from the AVG diode. The schematic shows it and the cathode taken to chassis potential. The AVG is then taken from another 1 Meg resistor that follows the volume potentiometer in series, being taken to the Mixer grid and IF tube grid. Or maybe I'm missing something? So far as I'm aware from the Chas Miller book it's more normal to take the IF amplifier to the AVG diode with a set bias resistor. I'll have to look at it again and see the logic behind it.
The HMV seems more orthodox.
