[Kenwood] TS-430S problem

[Everett Swift]

Thanks Rob, I forgot to include in my email the list of what I have done 
so far, Already tried that 2 times.

So far I have:
tested the radio on a different power supply, cable, antenna and tuner.
re soldered every connection on the final circuit board 2 times.
checked the ground in the antenna connector.

The only parts I have NOT replaced is the IF board, The final assembly, 
or any parts on the front (switches, display board, ect.)

The only reason I haven't replaced the Finals or the IF board is I don't 
have any available.

I spent every penny I had saved getting my ham license and getting the 
radio and other equipment so I can't afford much to get it fixed or I 
would ship it to you to repair.
My guess is it would cost as much to have repaired as I paid for the radio.

I have a VOM and an oscope but I'm not good at the scope yet.

Any idea you have on what I can do to fix it would be greatly appreciated.

Thanks,
Everett Swift,
KD8JWJ




Rob Stampfli wrote:


> On Wed, Jan 07, 2009 at 09:52:55PM -0500, Everett Swift wrote:
>   
>> Hello,
>> I need help with my TS-430S.
>> It receives fine but when I transmit the transmit power starts out at 
>> 100 watts with a rapid fluctuation of a few watts, after a second or two 
>> the wattage swing gets larger and the power slowly drops to nothing.
>> The Final heat sink gets warm and the fan kicks on.
>>     
> ...
>   
>> I cant afford much money, I got my License a month ago and spent every 
>> thing I could afford on this radio, tuner and power supply.
>>
>> But If you know of anyone who can fix it and not charge $50 an hour let 
>> me know.
>>
>> Thanks,
>> Everett Swift
>> KD8JWJ
>>     
>
> Everett,
> This sounds like it might be what is a fairly common problem with early
> TS-430S units.  If it is, the fix is fairly simple and essentially free
> it you care to tackle it yourself.
>
> On the finals board of units manufactured in the first year or so,
> Kenwood used some pass-thru rivets that over time developed a resistance 
> and caused power fluctuation problems.  They later soldered these rivets
> to prevent this failure mode.  You can take out the board and do this
> yourself -- and you'll have to if the transistors themselves have been
> fried because of this problem -- but that is a pain and there is an
> easier workaround if the drivers are still good.  Richard Measures, AG6K,
> came up with an alternative fix that worked for me.  Go to:
>
> http://www.somis.org/430.html
>
> and search for "loss of power" for Measure's description and his solution.
>
> Good luck,
> Rob
>
>
>