[Elecraft] Unstability in KPA100, cured

[Marteinn Sverrisson]

I have observed instability in my K2/KPA100 rig,
sometimes the KPA100 goes into oscillation, and the ALC goes way up,

I observe this on SSB and CW as well, with about 90W out.
The antennas I use, a dipole and vertical, are  just 15m and 10m from the rig.
Both antennas use common mode 1:1 Baluns to choke off RF currents.

On some bands there is strong RF field in the shack as indicated on the
Field Strenth Meter in the shack and this coincides with the unstability.

I can cure this problem by inserting a 2Watt 270 Ohm resistor in the input
circuit on KPA100 as suggested by WA7GXD in his article
"Remoting the KPA100 into the EC2 Enclosure"

This reduces the overall gain in the transmitter section and now there
is no oscillation.
This mod does not affect output power of the KPA100.

73 TF3MA
Matti