[Elecraft] KPA1500 RELIABILITY

[BRUCE WW8II]

I have a KPA1500 . One of the first ones built, ran perfectly until earlier
this year, when without reason it went from 1400 watts to 700 watts while
running CW, NO WARNING. The LDMOS DIED..  Returned to the factory for
repair, cost me $718 plus my shipping costs.   After about 12 weeks I
received it back. .  I have not yet put it back on the air because I have
since gone back to my reliable Ameritron AL1500 . I can repair it without
having to send it back for special repair because I do not have the tools
to replace the LDMOS.  Tubes are easy to change.
Although it is nice to be able to change bands and be ready to transmit no
tuning, 160-6 meters, I'm just not sure I trust it though, I need
reliability.  NOT SURPRISES.
The question is, is there a common component failing? and it looks like
that it is the LDMOS from the posts I am reading.

Bruce WW8II

On Sun, Oct 30, 2022 at 11:44 AM <john at kk9a.com> wrote:

> Is there a common component failure with this KPA1500 amp or does something
> different break every time?  Is there a certain mode, power level or type
> of
> antenna/feedline that causes failures?  I also monitor the SPE Expert list
> and some people have multiple LDMOS failures while others have no issues
> ever. N4ZR posted a similar question two months ago when someone else had
> multiple LDMOS failures and I did not see any responses.
> http://mailman.qth.net/pipermail/elecraft/2022-August/290628.html
>
> GL,
> John KK9A
>
>
> W3AB wrote:
>
> I don't have one but I do have access to one. It is making UPS rich
> going back and forth. Is there a reliability issue with these amps?
>
> ---
> 73 de W3AB/GEO
>
>
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