Kenwood TS-830S - Bandswitches

A customer came to us with this Kenwood TS-830S right out of the 1980's.  This hybrid radio isn't something we see everyday.  It is clean and well cared for, however the band switch failed to select the 40 meter band with any reliability.

There are lots of notes on how to do this, so I won't go into a lot of detail since someone else has documented this procedure very well.  https://www.k4eaa.com/bandswitch.html

• Pull the final tube nearest the center of the radio, and the driver tube.
• turn the bandswitch to 160m and loosen the setscrew
• turn the bandswitch to 30m and loosen the setscrew
• pull the shaft straight out
• unsolder the 3 wires, and disconnect all connectors
• undo the mounting screw and pull the board out.

Suffice it to say that the band switch contacts were not well attached electrically to the board traces.  Many were corroded, or had loose rivets.  I saw suggestions on how to attach them with conductive paste.  This didn't seem like a good solution, when solder is king!  One contact was pretty badly twisted, so that had to be addressed with some fine mechanical adjustment to get it just right.

A fine diamond-tipped engraver was used to clean the corrosion from each contact, rivet, and trace.  It was then easy to flux and solder the contacts directly to the board trace.  I fixed EACH and EVERY contact in ALL the bandswitches, not just one.  They would all eventually all succumb to failure if left alone.  Each switch contact slider was treated with De-Oxit and checked for continuity.  This fix will outlast the rest of the radio.  The plastic parts have already begun to crack.

The RF board wasn't too hard to take out, but there were three wires that had to be unsoldered.  One was hidden under the board.  (Thanks a lot Kenwood!)

All back together and right on frequency.