So this came into the workshop recently for repair, sadly as per the norm I don't have pics of the current state of the ongoing repair, if I remember to when next working on this I might take some only due to the wide extent of the damage. Customer report not working no transmit no audio, bench report no audio (speaker disconnected ?) transmit sometimes, receive mostly but anything up-to 500kc off frequency random.
Further findings were either full output power and or little to no output power, VFO unit PB-2445 not setting up as per service manual specifications. I had a source of one of these boards so a drop in replacement solved some of the transmit problems and put the receive back on frequency.
Remaining problems of note, random low power output in the order of a few 100 mili-watts, found the drive ALC line to the RF modules was not as per service manual setup. Reluctant to make transceiver alignment adjustments to a radio that was very unstable I lifted a few of the electrolytic's for inspection some measured bad ESR but what suprised me most was the extent of the leakage onto the PCB. Removal of these SH%^y caps around 30 of them, deep cleaning the board and replacement with decent branded caps has brought about and good return to service of the board and radio.
Now although the radio now works I am going to have to go through the remaining 5 boards and potentially replace the caps there as well.
Further findings were either full output power and or little to no output power, VFO unit PB-2445 not setting up as per service manual specifications. I had a source of one of these boards so a drop in replacement solved some of the transmit problems and put the receive back on frequency.
Remaining problems of note, random low power output in the order of a few 100 mili-watts, found the drive ALC line to the RF modules was not as per service manual setup. Reluctant to make transceiver alignment adjustments to a radio that was very unstable I lifted a few of the electrolytic's for inspection some measured bad ESR but what suprised me most was the extent of the leakage onto the PCB. Removal of these SH%^y caps around 30 of them, deep cleaning the board and replacement with decent branded caps has brought about and good return to service of the board and radio.
Now although the radio now works I am going to have to go through the remaining 5 boards and potentially replace the caps there as well.
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