[Elecraft] power requirements for a K3S, KPA500, KAT500, P3?

[Jim Brown]

On 6/14/2018 10:18 AM, ANDY DURBIN wrote:
> When I added my KPA500 to my TS-590S station I found the drop in mains voltage unacceptable.

I'd bet that was because of the IR drop in the long #14 wires feeding 
the outlet (and maybe other stuff running off that circuit).

Yes, 240VAC is better, simply because it requires half the current, and 
thus half the IR drop.

>   With this power distribution arrangement I run my KPA500 at 500 W output and PA voltage does not usually drop below 60 V.

Remember that there's a three-position jumper that selects a transformer 
tap inside the amp to adjust for line voltage. Access it by removing the 
top cover, and RTFM to learn how to set it. Unplug from power, of 
course. The KPA will go into protect mode if the HV is too high when NOT 
transmitting (greater than about 82V) and too low when transmitting 
(less than about 55V), so the key is to watch that voltage after 
changing the jumper.

We run two K3/KPA500 for 7QP and CQP county expeditions from two Yamaha 
2000i generators, which are providing 120V. We're running about 40 ft of 
#10-3 from the generator to the outlet where the amps are plugged in, 
and typically get 500W from the amp. Team leader W6GJB bought a 
"strapping kit" to run the generators in parallel, and changed the 
breaker on the one feeding the station to 30A. We do this for the 
generators -- they're happier in parallel with keyed CW.

73, Jim K9YC