[Elecraft] Troubleshooting KAT100

[Don Sandstrom]

The power control of my K2/100--KAT100 combination is acting 
up. This happened after a nearby lightning discharge (rare 
in the Seattle area). Power output does not track the power 
control setting very well. For example, with the lowest 
"high power" setting of 11 Watts, I am getting about 20+ 
Watts out. Also power control is not stable and "hunts" 
between levels about 5 Watts apart. I see this at all power 
settings, including low power settings.

I went through the alignment and test steps in the KAT100 
manual starting on page 27. In the Power 
Calibration-Reflected step I measure zero voltage at pin 5 
of U5, not 1.8 Volts as expected (using 10 Watts RF power 
for this test).

In the Power Calibration-Forward step the 1.8 volts is 
present at pin 3 of U5.

I suspect D2 was blown by the EMP from the lightning. Any 
suggestions as to how to confirm this? What else should I 
look for?

Other than the power control, the tuner still works and 
auto-tunes, although I haven't confirmed its really 
matching. The rest of the equipment seems all to be okay.

Thanks, Don, W7VXS