23-01-2014, 08:43 PM
Many thanks to all who replied.
I bit the bullet and removed all the transistors from the audio board (even the BC108!).
With all transistors removed I cleaned the PCB where the transistors were, with solder wick. Found some more leaky caps and replaced them for good measure.
Got some matched pairs of AC127/9 from vintage-parts. I had a spare BC108 anyway.
Fitted all the transistors and connected to the power supply and BINGO, quiescent current down below 10mA.
Adjusted the pots to give 8.85 volts and 4.0mA.
Fitted the audio board back into the set and reconnected.
It now works like a dream on both wavebands.
I just need to check those pesky germanium transistors to see which one was the culprit.
Thanks again for a great forum and all your help
Regards
Dave
I bit the bullet and removed all the transistors from the audio board (even the BC108!).
With all transistors removed I cleaned the PCB where the transistors were, with solder wick. Found some more leaky caps and replaced them for good measure.
Got some matched pairs of AC127/9 from vintage-parts. I had a spare BC108 anyway.
Fitted all the transistors and connected to the power supply and BINGO, quiescent current down below 10mA.
Adjusted the pots to give 8.85 volts and 4.0mA.
Fitted the audio board back into the set and reconnected.
It now works like a dream on both wavebands.
I just need to check those pesky germanium transistors to see which one was the culprit.
Thanks again for a great forum and all your help
Regards
Dave
