Along with what Don Wilhelm suggests, I would also look at all the RF board SMT IC's on daughterboards and see if any of the pins on the IC's themselves are not 100% soldered. I had a similiar problem on my K2, and the problem turned out to be an unsoldered pin. Once it was soldered, and a connection made, the K2 was up and running.
73, David KC9EHQ K2/10 #7164 ________________________________ From: Ben Byer <[email protected]> To: [email protected] Sent: Saturday, October 27, 2012 6:44 PM Subject: [Elecraft] [K2] POWER control has no effect on actual transmit power I've had fun putting together K2 #7373, and am finally at the point of doing the 40-Meter Transmitter Alignment (manual, p.78). I have the unit connected to a 50-ohm dummy load, and am trying to tune L1 and L2 to show 2W on the internal wattmeter. When I press TUNE, the measured power ranges from 0.2W-0.4W. I can adjust the POWER knob to show 0.1W - 15.2W while the unit is idle, so the knob reading circuit works -- but adjusting the knob doesn't change the reported transmit power even slightly (remains 0.2W-0.4W), and neither does adjusting L1 or L2. I suspect that the measurement is correct, because the overall unit power consumption is measured as 11.9V 0.20A when idle, and 0.42-0.44A when in TUNE mode (regardless of what I set POWER to before enabling TUNE -- same result with 0.1W vs 15.2W) I already checked the voltages on RF Q5, Q6, Q7, and all seem reasonable. (Actually, initially I measured 0v on the Q6/Q7 collector during transmit, and discovered that I had swapped two wires on T3. Fixing that brought the voltage up to almost 12v, but did not change the transmit power). Any suggestions? Thanks, Ben (KJ6ZGJ) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
