[Elecraft] KAT100 or KAP100 problem

[Douglas Westover]

After several months of flawless operation the KPA/KAT
pair seems to have developed a problem. It only occurs
on 30 meters and manifests itself by the inability to tune
the 30 meter antenna at the high power (20 watt tune level).
Dropping to low power it tunes properly as before. When
it fails to tune I get a "High Reflected Power" warning and
the output power as read on an external wattmeter goes
absolutely crazy as if the amplifier has gone unstable.
However if I substitute a 50 ohm dummy load it behaves
properly at any power level.

Again this only happens on 30 meters and there have been
no changes in the antenna.

Any speculations appreciated!

Doug
W6JD
K2/100 #1626