26-10-2017, 04:00 PM
I have replaced T3 (an AF178 with a very low hFE) with one of the original AF 114 (with a high hFE). Voltages (relative to 8.22V on the HT rail)are: B:6.8V. E: 7.3V on T3)
Injecting a 1kHz or 470kHz(non-modulated sine wave) into the bases go all the transistors yields no corresponding sound.
I played with touching the ends of a new diode over the PCB tracks where I assumed the original detector diode was situated...no sound (and, yes, I did turn it around).
Let me know when I am becoming an unbearable nuisance...
Thanks,
Richard.
Injecting a 1kHz or 470kHz(non-modulated sine wave) into the bases go all the transistors yields no corresponding sound.
I played with touching the ends of a new diode over the PCB tracks where I assumed the original detector diode was situated...no sound (and, yes, I did turn it around).
Let me know when I am becoming an unbearable nuisance...
Thanks,
Richard.
