[Elecraft] KPA500: Reduced HV sag by 9V by using 240V feed

[John Harper]

I ran a 240V line for the same reason - excessive drop when operating the amp (not the KPA500) from a 120V line. As an experiment, I went around the house measuring the voltage drop at various distances from the breaker panel by plugging in a 1000-watt hair dryer. I knew what the results would be - increased drop as distance from the panel increased - but it was neat to "prove" it to myself.

The hamshack is at the opposite end of the house but a dedicated 240V line solved the problem:
http://www.ae5x.com/blog/2011/05/14/mains-stability-during-transmit/

John AE5X



>When I purchased my KPA500 at the end of last year, I didn't have a 240V
>outlet in the ham shack, so I as forced to run off of a 120 volt line.  In
>addition the ham shack is about 75 feet away from the breaker box, so there
>was some pretty hefty IR drop on the 12AWG cable.