[Elecraft] K1 transceiver kit won't transmit

Foreman kelnmart at mtaonline.net
Mon Mar 4 01:49:49 EST 2013


My son and I have been building a 20m & 15m K1 over the past year. Great kit! It is assembled and we are trying to finish aligning the radio. however, it will not transmit. We have tried signal tracing it and cannot get a reading on any of the test points. Receiver works fine. We did extensive multimeter testing and found that IC U8, SA602AN, was out of tolerance. We replaced it but the transmitter is still inop. A very kind Elmer will assist us with test equipment but wanted to gather opinions from the reflector participants on how to proceed. Just to bring all the information together here in one place, the great folks at Elecraft shared the following recommendations:

Filter Board RF voltages using a scope at these filter board connector pins:

P1-4 Premix oscillator signal 200-500mVpp
P1-6 Premix signal output signal 200-500mVpp (must be peaked with the bandpass trimmers)
P2-1 TX Buffer output 1-3Vpp
P2-8 Filter board TX output to Driver 1-3Vpp
P3-1 PA output up to 40-55Vpp
P3-8 Output from lowpass filter 40-55Vpp

Vpp = RF volts peak to peak.
mVpp = RF millivolts peak to peak.

An RF probe will show the rms RF voltage levels, or about 35% of these pk-pk values. Appendix E, or any ARRL Handbook shows how to build an RF probe. We also sell an RF probe kit for $10. Use an oscilloscope if you can get access to one.

Test the rig on all bands too. The filter board is difficult to align the first time, so be patient when aligning it, and try to peak it on signals in receive, or in transmit with an RF probe or scope at the indicated places shown above.

Thanks. 

Martin, KL3ID
Micah, KL3IE


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