This receiver was given to me by Charles KC8VWM. On the site QRZ.COM, he wrote that instead of the G3, which stopped working well, he bought another receiver. I wanted to buy it for repair but after little conversation with Charles, he offer it to me for free and G3 ended up with me. Charles was kind enough to put a solar panel in the box, so now I’m even better prepared for the blackouts that have become regular.
I had a similar receiver Degen 1103, but I gave it to my daughter and I had nothing with which I could listen to all bands, and small enough to fit in my emergency backpack.
It turned on and worked on VHF, but the strong smell of smoke and my curiosity made me open it. Some of the buttons inside had pieces of adhesive tape stuck on them.
I couldn’t get the flat cable out of the connector, so I unscrewed the board with the screen from the case and continued working with the connected boards.
As it turned out, part of the epoxy glue that was used to glue the antenna to the case collapsed and leaked onto the board.
Washing the board from it and removing the damage was not easy. Also the damaged rivet was restored. Previously, the trace was cut and resistor was soldered on the other side of the board.
At the same time some capacitors were changed.
I also had to tinker with the body, washing off the remnants of the old polish paste and restoring the places for the screws. The plastic is very brittle. I used acrylic glue and baking soda.
I did not find any diagrams or a service manual for this device, so I adjusted it according to the information I found on the Internet:
– SYNC frequency adjustment: C113 (left of ribbon connector)
Sync trim procedure: turn C113 ever so slightly and compare audio results by toggling between SYNC-USB and SYNC-LSB on known stable station. Find “sweet adjustment spot” so that both syncs sound practically the same.
– SSB frequency adjustment: C140 (next to SW wide-nar selector)
SSB adjustment procedure: set +/- fine tune wheel to its mechanical center position. Adjust C140 ever so slightly to find the “sweet adjustment spot” so that both SSBs, USB and LSB, sound clear and no whaling can be heard on either.
– AM frequency adjustment: Q31 (above ribbon connector, next to shielded block). This seems to be good as set by the factory.
Reception is excellent on VHF, it also works well in SSB. The work of the sync detector is strange, there was also a howl when receiving some AM stations.
I glued the broken stand with double-sided tape.
I noticed this howling appears only when receiving strong stations on short waves and constantly on medium waves, even if there is no signal at all. I attribute this to the fact that due to the large interference on medium waves, for the receiver on this band, the signal is always present. Volume control also affects this howl. Nothing is heard at minimum volume. Never on VHF.
So I checked everything again and decided to improve the shielding. I added a spring to connect the shield on the screen to the shield on the main board, as well as two additional ground connections on the LC72137 PLL synthesizer shield. Looks like it helped.
I also noticed that when the external antenna is disabled, its icon continues to be present on the screen. It turned out that there was a bad contact in the connector, so I also replaced it. I hope that’s all.