This is my initial work with developing a digital modem board for RF use. I have various digital modulations working on this prototype. The AVR32 isn’t quite enough to do everything on board.
After getting thru most of the alignment I’ve moved onto the PLL. The board appeared to be in good shape visually but after doing the first initial checks at TP1 I realized there was a problem. After carefully removing it I noticed a small gouge on the edge of the board which had broken trace connectivity. I repaired that with a small bit of foil and solder. I also realized that the caps had been replaced by the previous owner with larger volt caps which normally doesn’t cause an issue except the fit was too tight and smaller 10V caps are of preference on this board so they fit nicely. I continued on after removing the caps and ordering parts from Mouser to replace the large 50V rated caps with the 10V. So more waiting.
After replacing the caps and a complete the alignment the TS-430S now works at least as well as it did new.
I made it a bit deeper into the TS-430S this weekend. While checking the alignment, it was clear there was an issue with the RIT. It didn’t seem to work and I wasn’t seeing what I should have been at D5. After looking around a bit on the board I found that VR3 was working sometimes and sometimes not depending on what mood it was in. After replacing VR3 I wasn’t getting a proper RIT 9mhz signal but everything is more consistent now. I noticed the dreaded glue around the 9mhz osc which concerns me and I’m very suspicious of that area. When I have time next step is to remove all the glue from that area and try and determine if that has something to do with RIT not functioning.
07/24/2011 After deeper inspection of the glue area it became very apparent that X6 (9mhz) was no longer connected to the board. The leads had broken off right at the PCB. I’ve spent some time trying to source a replacement. Hopefully I’ll locate one soon.
08/01/2010 The control board now checks out with the 9mhz replacement. On to the PLL board.
I’ve been doing some clean up on the filter unit for the Kenwood TS-430S HF radio. Some bands were not working and the filter unit was suspect. I had already tried the prescribed 12 V DC current treatment without any changes on the bands that weren’t working. I noticed several bad joints and manually disassembled each relay and checked its operation. At least two of them were not making good connections and required cleaning with some contact cleaner and a dollar bill. After this cleaning they seem to be working. I also noticed several bad solder joints. Here is some photos of the board.
07/14/2011 – After removing the IF board from the TS-430 I could see some issues right off hand. The top site of the board was realitivly clean although I noticed some excess thermal compound on the regulators which gave me a hint that this IF board had been repaired at some point. Getting it out I could see lots of oxidation, burn traces at one of the regulators and at least one connect that had ripped the traces from the board. Tonight I cleaned up much of the board tested all the diodes on the rear of the board, and repaired the 5V traces. At this point the radio seems to work but I don’t have very good recieve and it still only transmits on some bands. On the bands it does transmit on it does full output which is a good sign. I’ll be working on the IF board for the next few days as its in bad shape on the rear side.
07/18/2011 – Well thus far, I have replaced the traces on the 5V regulator with jumpers as the eyelets were missing and that area of the board wasn’t in very good shape. I also located a burnt or gouged trace which will need repair. A missing eyelet was found on Connector 10 and I ended up glueing the connector to the board and replacing the trace with a wire. After looking at the board from the top I’ve noticed several missing caps. I expect someone has tried to repair this board and during checking cold solder joints they may of pushed the caps off the board without noticing.
07/19/2011 The gouged trace has been repaired. Now the IF section seems to be working at least a stage or two away from the audio section. I ended up with a TX issue which was a bad connection at the molex connector which slowed progress on the IF board issues.