K2 #7150 is assembled. It receives, but shows low power and high current on transmit. Doing the 40 meter transmitter alignment procedure, I get these results.
When not transmitting: 13.6V, 0.22A TUNE, 5.0W selected: 5.0W indicated, 13.3V, 2.00A TUNE, 10.0W selected: "Hi cur" warning, 5.8W indicated, 13.2V, 2.50A During transmitter signal tracing, trouble first shows up in the "transmitter mixer, buffer, band-pass filter, T-R Switch" checks: (All measurements Vrms using RF probe, "key down") Xmit mixer output (U10, pin 4): Expected: 0.16, actual: 0.0019 Buffer output (U9, pin 6): Expected: 0.200, actual: 0.0927 Ratio of Buffer output to Xmit mixer output: Expected: 12:1 Actual: 49:1 Band-Pass Filter Output (W6): Expected: 0.030, actual: 0.0318 T-R Switch #1 Output (D1 anode): Expected: 0.029, actual: 0.0305 The Pre-driver, Driver and PA voltages are, with one exception, also unexpected, but I'm guessing that's a result of the previous stage being all goofy: (All measurements Vrms using RF probe, "key down") Pre-driver output (Q5 collector): expected 0.120, actual 0.194 Driver input (Q6 base): expected 0.026, actual 0.017 Driver output (Q6 collector): expected 1.8, actual 2.8 PA input (Q7 base): expected 0.38, actual 1.19 RF detector input (D9 anode): expected: 2.0, actual 1.98 Where should I look next? - Wayne Conrad ______________________________________________________________ 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
