[Elecraft] Problem KAT100 vs. KAT2

[Steve & Anne Ray]

Strange problem on the higher bands 10, 15, 20.

If I disconnect my KAT100 tuner and load the K2 through the KAT2 tuner I get
a good match, no power jumping around and with the power set at 10 watts in
the tune position the power holds steady at 10 watts.

However, if I go through the KAT100, the tuner loads fine, but when I go to
10 watts output, I get the power jumping around at 5 to 7 watts, and high
current indication.  I have the KAT100 and the KPA100 in a separate case.
All testing has been done with a good 50 ohm dummy load and I have even
tried another dummy load just on a long shot.  I also tried with the dummy
load right at the output to see if I had problems with my antenna switch or
coax, however the problem remains the same.   I have put on the new shield,
for the KPA100, the new firmware (1.04) for the KAT100, all modules are
grounded together, and go to a good outdoor ground.

I have not tried the ALC resistor mod as the power is rock steady on 40
meters, and steady with the KAT2 tuner  on 10 meters, the power only jumps
around with the KAT100 tuner.  I have also put the bypass cap in the control
cable connecting the KAT100 to the K2.  Also tried another control cable
with the same results.

Any ideas?
Thanks

73,
Steve Ray K4JPN ex K1VKW
EM82ep Warner Robins GA
Elecraft K2 1422 & KPA-100
Heath Fan HW-101, HW-8