[Elecraft] K2: Power control KPA100/KAT100 - have I fried the EL5146C?

[Sverre Holm]

My KPA100/KAT100 is located 5-6 meters away from the K2 and I am afraid I have gotten RF into the VRFDET line and fried the output buffers on both of them. The Power display on the K2 does not reach full value especially on 15, 12, 10 meters. In  this setup I think it is the voltage from the KPA100 that controls the K2's power output.

When I measure the KAT100 without the KPA100 (easier to measure than the KPA100) I have the following input/output relationship on  the VRFDET amplifier, U2,  at 7 MHz:

0.5 W: in 0.5V out 0.85 V
1 W: in 0.77 V out 1.2 V
5W: in 2.0 V out 2.2 V
10W: in 2.4 V out 2.3 V

As the amplifier is supposed to have a voltage gain of 2 I think this is suspect, so have I fried the EL5146C (probably on both the KPA100 and the KAT100)?


Sverre
LA3ZA