My Elecraft 222 MHz transverter had been acting flaky for quite a few
months. Its local oscillator freq had shifted recently by another 5 khz. A
few weeks ago, I had the time to start looking into that. Using the manual's
adjustment procedure, I found that the LO test point's output level was
below the minimum required. Tweaking some of its inductor slugs brought it
back up, but the level would sometimes drop down again after being on a few
hours. Touching some of its components sometimes would pop it back up again
for a while. Reflowing the solder in the LO circuit area did not help
anything. Finally, a couple of weeks ago, it failed completely. Hurray!
Maybe now I can find the faulty component. The voltage readings of its
circuit had changed from when I last measured them but indicated that the
transistors were still OK. A check using a little SDR confirmed that indeed
there was no 194 MHz LO oscillation taking place. The crystal? Found one for
sale by Q5. It arrived in about 10 days after floating around in the USPS
system that kept reporting it late in getting to here or there. But a week
ago it arrived, and simply placing into the waiting PCB through-holes for
its pins in the PCB.voila! A strong 194 MHz spike immediately appeared on
the SDR. Before soldering it back in with its oven, I tested the oven to
confirm that it was not the culprit by loosing control and frying the old
crystal. It tested good; its current consumption went down after turn-on and
a cooking thermometer showed the internal temp leveling off at around 95 deg
F. So back in they went. Beacon K2DLL's signal was now steady, and it seemed
the freq offset at 222 was only about 1 khz. Nice crystal!! Thank you Q5.
What better place to test it on the air than the activity night! Only
problem was, I had to be in a ZOOM meeting at 8 pm that would likely last an
hour or two. But nothing says I can't turn on the radio in the background.
Just before my Zoom started, I saw W1FKF decoding on FT-8. The temptation
was too great, and I double clicked on his CQ (without having checked audio
level-oops). He came right back to my call. I was only running 6 watts-
transverter only. And then along came a call to WZ1V off the side of my
antenna, and later I saw a decode on N1BUG, 312 miles away, and answered
him. I almost fell off the chair when he came back to my puny 6 watt signal.
Wow, good ears! Then had a couple of sequences with N1YCQ. My yagi was
pointed NE the whole time, no chance to try and peak it on anyone and forgot
to turn it SW and listen that way. This morning I found that my FT8 audio
level was a bit high- sorry about that.
W1FKF FN43 me -10, he +08
WZ1V FN31 me+12, he+26 (is that all Ron?)
N1BUG FN55 me -21. he -08
N1YCQ FN41 me -15, he -10
I guess it's working again.
TU and 73,
Chet, N8RA
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