[Elecraft] KPA-500 and RTTY

[DGB]

Am running my fairly new kpa-500 in the rtty contest. It is situated out 
in the open.

it from 220v and during the run it's current runs at 10a and 64-74v. The 
temp starts at 35c and as I run it slowly creeps up to 55-57c and kicks 
out with the error message of "Pwr In High".

I'm only driving this with a K-3 set at about 13w to drive the amp to 
350 watts. I wanted to take it easy on the amp and seems from the specs 
that it should handle that. The amp. seems to be real sensitive to the 
driving power of just a watt difference from the K-3. The power varies 
at the amp from 250-350 watts when running and not fiddling with the K-3 
power knob. I have the fan set on 1 and didn't make any difference if I 
set it to 6, it still would kick out in due time, just slightly longer. 
Must mention it does it whether it's into a resonant antenna or a dummy 
load. The temps just slowly climb.

Anyone have a similar problem, makes it useless for rtty contesting and 
running. No problems in CW contests at full bore!

73 Dwight NS9I.