[Elecraft] KPA500 troubles

[Jim Brown]

On Wed,11/11/2015 12:10 PM, W4GRJ wrote:
> Got the KPA500 back from Elecraft.
> Problem found: L22 and other components in the 60M low pass filter circuit
> burnt through the LPF PCB.

60M LPF??? Last I looked, the US power limit on 60M is 100W relative to 
a half wave dipole.



> Repair $650 later: Replaced low pass filter module and installed QSK mod.
>
> On the phone I asked what caused the failure, answer was no idea other than
> component failure. I understand stuff fails but I thought I would get more than 2 years before a major expensive failure.

The LPF is on the output of the amplifier. One possible cause of failure 
could be lightning.

> Previously had a Ameritron ALS-600 for 5+ years never a problem, sold it to
> purchase the KPA500.
>
> Sometimes the grass is not greener.

My only experience with an ALS-600 was at a contest station in PJ4 
several years ago. I found it to be a really inferior amp - most of the 
time, I was lucky to get 300W out if it. No comparison to a KPA500.

73, Jim K9YC