[Elecraft] K2 - Receiver silenced

[Bill Coleman]

I had an odd failure of my K2 this past weekend. I had taken it camping 
with me. While it was turned on and receiving, the S-meter slowly rose to 
full scale, then went to zero, and I get no audio from the receiver. 
Turning the RF gain control results in no S-meter indication.

Now back home, I've done some diagnosing.

I noticed that the Q2 transistor on the control board is very warm after 
only half a minute of operation. The emitter of this transistor is at 8.4 
volts, the base about 7 volts, but the collector is only about 3.5 volts. 
This indicates to me that something is drawing a lot of current on the 8R 
line.

I removed all the modules until I was down to the basic K2. Still the 
same. 8R line is about 3.5 volts, and there's no S-meter response to the 
RF gain control. The S-meter always stays blank.

The transmitter section appears to work fine.

Something is happening on the 8R line. Any suggestions where I might look?



Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901