[Elecraft] K2 problem, troubleshooting (alignment and signal tracing)

Jason Marten martenjj at hotmail.com
Sat Mar 12 17:32:18 EST 2005


Ok, I've got a couple of problems here with my K2, I was wondering if anyone 
could help.

I put together my K2, as best as I could.  It receives fine (as far as I can 
tell) on a couple of bands that I've tried so far.  I haven't really put it 
through the test of transmitting.  However, it does heat up my dummy load, 
and causes the TV in the adjacent room to thump when hooked up to an indoor 
random wire (one reason why I haven't transmitted much!).  I sometimes get 
HI CUR warnings, even when at 5 Watts.

The only trouble I had with testing and alignment was under Part 3 of the RF 
board, under "Transmitter Alignment".  My problem here, is that when I 
adjust L9 (30 meters) and C23 (20 meters) for maximum output, I don't really 
see a peak anywhere around 2 Watts, if I turn it just a little bit it goes 
way past 2 Watts until I get a HI CUR warning.  I've tried this many times, 
and I always get the HI CUR warning.  I decided to get L9 and C23 close to 2 
Watts, and went on with aligning and testing.

A little while ago, I brought my K2 into a club station, and even at 5 
Watts, I noticed I was getting HI CUR warnings a lot, so I stopped using it 
and I decided to go through troubleshooting (signal tracing and voltage 
checks) to try to see if I could find anything.

I built the RF probe.  "Preparation for Receiver Signal Tracing" (Pg 10) 
went fine.  Same with "PLL Reference Oscillator and VCO" (Pg 10) and "BFO" 
(Pg 11).

On "Low-Pass Filteass Filter, and T-R Switch", I have some questions and 
problems.  It says to use a signal generator or test oscillator.  Will the 
XG1 work here?  This is what I was using, but it mentions setting the signal 
generator to 0.14 Vrms.  Does this part not apply to the XG1, and which 
setting should I be using on the XG1?

Then, when is says to hook up the probe to D6 and adjust the band pass 
filter for a peak reading (I was trying to adjust L1 and L2 for 40 meters 
using the XG1), I could not get any reading other than 0 volts.  Also, on 
the following readings (W1, W6, both sides of D6, etc), I also kept getting 
0 volts.  I've been trying to look at the schematic to see where to look, 
but haven't been able to figure things out.

Do I have some sort of problem with the Band Pass Filter?  Where do you 
suggest I look for problems?  Thanks!




More information about the Elecraft mailing list