A beautiful radio purchased by the old man in 1995 with his retirement money. It served him well until Feb. 2020 when the integrated antenna tuner began to give problems. Sporadically it would not work. He said that the internal tuner relais continually clicked, trying to look for a match to the antenna load but without success. Other times it would work instantly. The shop that he purchased it from was not willing to even look at it and so he brought it to me.
The very first thing I do, when I get a radio, is to try to reproduce the problem being reported. Often, the issue is with the antenna or surrounding equipment and not with the radio itself. In this case, I could reproduce the error with my dummy load connected to the antenna jack. It was time to crack the radio open.
The tuner board was clearly visible and I suspected a loose or cold joint in the PCB somewhere or perhaps a sticking relay. A few taps around the board with a large screwdriver soon confirmed my findings. So the board was pulled and given a closer inspection.
The board was flipped over and moved to the solder station.
Once there, it was given a good inspection using the microscope.
A cold joint was identified as the culprit and a reflow over all major joints was done. Inspection also showed that the battery was leaking, so it was also changed out and the holder cleaned.
Finally, the radio was opened up to use the 60m band which was recently assigned to Ham operators in Germany.
My Rohde & Schwarz communications tester, showed that the radio was bang on frequency and putting out loads of power.
During assembly, the voltage regulators were re-seated using new thermally conductive paste, as this is a known issue on these radios. The heat causes the compound to fail over time and so they were reseated and tested with the infrared thermometer to ensure good conductivity to the side wall of the chassis.
A fantastic radio, restored to it's original state and ready to serve the old man with hours of life left in it yet. Needless, to say, he was very happy to have his old set back in working order.
