Symptom: K2 with very low audio output, only the strongest stations can be copied. Have eliminated the BPF, attenuator, pre-amp, and so forth with signal tracing. Transmit stops increasing at about 4W, the control runs out of effect. So the K2 is alive, but something is wrong in the signal path.
The BFO area was redone with a mod (which I have no paperwork on, somebody else's radio). The components were dead-bugged onto the area around the T33 BFO toroid, and I believe they shorted out on the bottom cover. Using the included kit RF probe, test point TP2 has only 1 millivolt on it, but Q24 has about 0.4Vrms on the gate, which is fed from U11 pin 6 and through the BFO components. Thus, it appears to be a blown Q24, which is a JFET J310. Radio Shack has a MPF102, would that be OK to use? I've checked the respective datasheets of J310 vs MPF102, and I haven't found much difference in ratings, even the noise figure is about the same. Your comments appreciated ASAP! 73, Tyler N4TY ______________________________________________________________ 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
