Kenwood TS-430S Rebuild.



07/13/2011 Most of my spare time for the next few months will be spend refurbishing a Kenwood TS-430S HF Radio.  At this point the unit doesn’t have any RX or TX so it should be a challenge to get everything back into working order.

07/13/2011 Considering the radio’s age I started with basically taking it apart to see if any visible damage could be seen.  My main goal is to ensure the PA is good and perform some modification to ensure it stays that way.


While I had the PA removed, I checked all the LFP relays cleaning and testing each one.  The best way I’ve found to do this is to use contact cleaner and a pieces from a paper bag. Looking at the PA it appears to be in good shape.  The first order of business was to remove all old solder with suction and wick.  I removed the rivets and replaced with Z wires to ensure a long lasting connections to the PA transistors.  One thing to make sure is to make sure the mica insulators are retained during removal.  I did a complete cleaning of the board and sink.  I replaced the aging thermo compound.  A big problem I found was the fan was not connected. After replacing the wire and testing the fan worked.  I know that I want to modify the turn on temp but I’ll do that later.  I tested the transistor connections to make sure no shorts and that everything was ok.  Next order of business was to ensure I had good connections on all the board connectors.  Deoxit was used and I discovered a connector that was not connected to the correct place on the IF board.  After getting it all back together I turned the unit on with all the settings in Alignment position.  Care was taken to make sure the CAR was on lowest setting.  I can now receive and on most bands I now see 95-100 watts of power to a dummy load.  RX doesn’t seem to be very sensitive as I can’t tune in anything. TX seems to work on some bands to the full power.  On other bands the radio seems to have a problem.  As increase of the CAR while TX it pulls the voltage down and the radio resets clicking the relays along with it.

I tore deep into the radio and started alignment.  The boards had some oxidation on them.  I’ve decided while I have it apart to go ahead and replace all oxidized “lytics” just to ensure once back together it’ll last another 15-30 years.   I normally don’t like digging deep into a non-working device always afraid of making it way much harder to troubleshoot existing problems. I’ve noted some questionable solder joints on all boards and did a tedious cleaning of the traces.  The speaker connector from the IF board to the lid was badly damaged.  I managed to replace it with a computer switch header lead which works nicely on all the board connections.  While I’m waiting on caps to begin arriving for the values I don’t have in hand, I’ll be cleaning up the solder joints and testing connections on each board.  During alignment I also noticed that the RIT control isn’t working at all and no signal is present at the test point.  I’ll retest after cleaning it up and soldering.

07/14/2011 Well sourcing caps will take some time unless I can find a ready made list of values and sizing.  If anyone has such a list please let me know.  Otherwise I’ll come up with one as I go and post here to make it easier on others to repair their TS-430S .

08/08/2011 I’ve been continuing work by section in the posts below. I was able to source caps, as needed, from Mouser and Digikey

Below are other articles which continue the work on the 430S

IF Board

Control Board

PLL Board 

Filter Board


08/18/2011  The TS-430S is now completely functional and freshly aligned.  I’ve only made a few contacts on 40 meters but reports were good.