[Elecraft] K1 signal traced

[David L DuPuy]

Don,  here are the values for the Transmitter Signal Tracing.  Results are
shown for 40m (all okay except maybe MIX), and on the right are results for
20m, as measured on a 60 Mhz Tek oscilloscope.  The problem seems to start
between OSC and MIX, i.e., at U8 Transmit Mixer/Osc.

signal tracing

             40m 20m
shunt DRV to gnd
PRE      0.09 0.06
ATTN    0.05 0.05
OSC      0.06 0.07
MIX      0.05 0.05  LOW
BUF      4.3 0.9    LOW
TR1      2.3 0.5
BPF      0.4 0.2    LOW
TR2      0.4 0.2    LOW
TR3     0.01 0.04  HI
remove DRV shunt
DRV     1.3 1.1
PA     40 5.4    LOW
ANT     40 5.0    LOW
RFD     2.1 0.59  LOW

I'm having trouble understanding how the waveform at PRE and ATTN is the
same amplitude on 40 and 20, but very different past U8.  The signal at PRE
and BF is not a clean sine wave, but shows a modulation... true for both 40
and 20.  Is that normal?  The PRE and BUF 20m signal appears to be double
the 40m frequency.  I presume that means both X1 and X2 filter board
crystals are operating??  I really appreciate your continued help!!  (you
are very patient!)  David  AC4BN