[Amps] Alpha 87A problems

[Jim Brown]

On 10/2/2018 7:06 AM, Paul Christensen wrote:
> My remote ste uses a new Elecraft KPA1500.  So far, its PIN diode T/R
> system has been flawless.  However, it's distressing to see PA deck
> temperatures reach nearly 80 degs. C in RTTY and FT8 modes.

Thanks for a great analytical and thoughtful post. I have no opinion on 
the 87A's -- I have far too little experience with them nor knowledge of 
their control system.

I had K6XX's KPA1500 for a few weeks while he was in Germany competing 
in WRTC, and used it extensively on 6M running FT8. I also used it to 
work him and all but five of the WRTC competitors on 20M. It worked very 
well, but I felt that the fans and the firmware controlling fan speed 
needed some work so that the amp don't fold back un-necessarily when 
pushed on 6M, where it is least efficient.

73, Jim K9YC