[Elecraft] KPA500 and excessive drive

[Michael Walker]

You likely blew one of the Caps in the Low Pass filter.

If you open it up and have a look, you will clearly see the damage.

I've seen this done before on a friends that I had to repair for him.

I just replaced the blown parts and then swept it with a VNA to ensure it
was still operational.

Mike va3mw


On Sun, Jul 4, 2021 at 3:29 PM Jim Weatherford via Elecraft <
elecraft at mailman.qth.net> wrote:

> Last night I was trying to work 80m for the first time in a while, and my
> KPA500 faulted. I was tired, and didn't pay attention to the fault code but
> simply cleared it and tried again. After a couple of rounds of this, I
> smelled something burning and shut off the amp for the night.
> This morning I realized that the K3 output power was set to 100W on 80m
> even when the KPA500 was in operate mode, which explains the "06 PWRIN HI"
> codes when I looked at the fault table. Uh oh!
> Luckily, it looks like I'm still getting full power out on all other
> bands, so I believe the finals are OK, and I probably smoked components in
> the 80m portion of the KPA500 LPF bank. Any thoughts as to which components
> are most likely to be damaged by excessive input power? Should I simply
> replace all 8 caps and 3 inductors?
> 73,Jim WU6K
>
>
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