[Elecraft] K1 transceiver kit won't transmit

[Mike Morrow]

It helps to know **exactly** where in the manual the problem is detected.
It appears that you are building a two-band filter board, which is also
important information.

I assume that you are using K1 manual Rev. I, that **all** the testing on
page 46 (especially the late step on that page) was completed without
anomaly, and that the problem appeared at the step in the first column
on page 47 that states:

  "Put the K1 into TUNE mode. Using the alignment tool, adjust
  L1, L2, L5 and L6 for maximum output. If the output jumps up to
  well above 2 watts, exit TUNE mode, then re-enter it again."

(The last couple of K1 manual revisions corrected a problem that had
been in the manual for a decade that sometimes caused problems if
the errats sheet had not been followed.)

> ...it will not transmit.

It helps to know **exactly** what indications show the problem being
reported.

What does this mean, exactly?  Does it NOT go into transmit mode at all?
Does it go into transmit mode, but displays PO.1 for all adjustments
you make to the inductors above?  This could be caused simply by not having
the jumper on P3 on the RF board on the correct two pins (1 to 2), or missing.
Do you have an external wattmeter and dummy load that shows no output?
Do you have an external receiver that could detect at least the existence
of some transmitted signal?

The tuning of the two-band board is fairly broad, compared to the four-band
board.  But the peaking for transmit will still be rather sharp, compared to
what was required for receive.  It is easy to tune past the transmit peaks
and wind up with P0.1 shown in the display.

For the two band board (in contrast to the four-band board), it doe *NOT*
matter which band you align first.  If you have no success on the one band,
try the other to see if the anomaly is only in the circuitry for one band.

>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

RF voltages are nice, but the start of troubleshooting should verify first
a few DC voltages.  There should be 12 vdc on the RF board at the collectors
of driver Q6 and PA Q7 **even when not transmitting**.  Don't measure these
when transmitting, but check them in receive mode.  If there isn't 12 VDC
then, there won't be any point to checking anything else until there is.

Good luck.

Mike / KK5F