[Elecraft] KX-1 Did I blow my final?
Brian Wruble
[email protected]
Tue Feb 24 14:49:11 2004
Hi all:
I had a working KX-1 with 30M module installed. Measured power output was
2.5W on 20, 3.4W on 30 and 3.25W on 40.I installed the antenna tuner, and
everything looked fine.
I then did the KXAT1 power calibration, and the null on adjusting C9 was, as
predicted, very sharp. Then it dropped to zero.
I still had Xmit signals that I could hear on another rig, but much weaker.
Power output had become nearly zero.
I removed the tuner, replaced the jumper at J8, but still very little rf
power output.
All operations were using a 14V power supply. I used a DL-1 dummy load, and
I measured power using a DMM and using the conversion equation provided in
the DL-1 instructions. I left "Tune" on for under 10 seconds each time.
I have checked T1,L3,L1,L2 all ok.
DC voltages at Q1,Q4,Q5,Q6 are all ok.
I have RF at T1, lead 4, but no RF at the collector of Q6.
I tried a reset of the firmware to factory defaults, but no help.
My quick diagnosis would be a blown Q6, but I'm surprised if it happened
that easily. Is 14V too much for a short transmit period?
Any other ideas as to what to try would be greatly appreciated.
Tnx.
Another quick question: The schematic showing J8 mystifies me. It looks
like its pins are already hardwired together. I can't quite figure things
out there.
73 de Brian W3BW