[Elecraft] KPA100 Low Power on 30m & 20m bands

[Barry Cooper - Relcom]

Hi,
I have completed the final alignment and test of my KPA100 amplifier which is working well in almost every respect other than relatively lower power output on the 30m and 20m bands. Measured power output is as follows:

80m 117W
40m 113W
30m 71W - initially flashes "Hi Cur" message
20m 75W - initially flashes "Hi Cur"
18m 105W
12m 103W
10m 99W

Power output measured at antenna socket across 50 ohm load using Tek scope and calulating Pwr = Vpp^2/400.
I have checked the inductors and capacitors in the two LPF chains. Everything appears ok, i.e. correct toroids used wound with correct number of turns. All capacitors check out as correct value with correct placement.
CAL CUR set at 3.5 as indicated in setup. Power output displayed on K2 matches calculated output power to within 2-3W. K2 running barefoot gives more than 10W on all bands.

Help please! Where do I look next?

Barry
G4RKO
K2 - 4703