K1 Power Loss Followup

I have done the TX voltage checks without the filter and noise blanker boards mounted. Everything was fine just like when I finished the assembly. So no help there.

I have also received two emails with suggestions. W1TF suggested that I check D19, which protects the PA transistor. He had similar problems as I and he found that D19 was shorted. I checked but D19 seemed all right. Using the diode check function of my DMM I could measure something in one direction but nothing in the other. The second email came from WA2DKG , who suggested that I check R30, the emitter resistor for driver transistor Q6. He has encountered several K1s with that resistor open. I checked but it showed 3.7 ohms, very close to the nominal 3.3 ohms. So no luck here either.

I will now go on and do the signal tracing as described in the assembly manual.

Author: Alexandru Csete

Embedded software engineer in the satcom industry during the day. Radio amateur and SDR hacker during the night.