This is great info, thanks!? I just tried to adjust it with the
trimmer pot, and I could get it sorta close as long as the screw
driver was on the pot, but as soon as I took it away, the marker
tone changed significantly.? I can't get it close enough to be
accurate, so I guess my next option is to try and find a
replacement marker crystal and see where that gets me.? I'll do
some research to see if any are still available.? I appreciate
this a lot- definitely gets me much closer to having this problem
resolved!
Best,
?? Scott
On 7/20/2022 1:48 PM, Bruce Collins
wrote:
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OK. Does your radio have the WWV receive crystal
installed?
If yes, tune the receiver to it and zero beat the
carrier while listening with headphones.?
Then off tune a bit so you hear a 400hz to 800hz
“tone”. Don’t be confused by the modulated audio WWV also sends
out. It stops occasionally so there is only a carrier.?
Now flip the marker on. ?
If close in frequency you’ll hear the difference
in tone between the dead on carrier frequency of WWV and the
25KHz-100KHz crystal oscillator in your radio.?
On your regulator board (where the actual marker
crystal and oscillator is located), there is TC1, a 50pF trimmer
cap to adjust the marker frequency.?
If you can’t pull it in with that trimmer, you’ll
need a board repair or a new marker crystal.?
Another way is to go to 160m band and see if you
can use the preselector ?maxed out and tune in a local AM radio
station around 1600khz to 1700khz and zero beat their carrier
... which is frequently well within 25Hz to 50Hz too.?
On Wed, Jul 20, 2022 at
10:49 AM Scott Toth <
nd4l@...>
wrote:
Thanks?Bruce.?
Something is off somewhere, I'm just not sure where.? I
know that if I pull up the 14.300MHz Maritime Mobile
net, I can center the VFO dial on 14.300 and hear the
net fine, so I feel like the VFO and its dial are
calibrated accurately (at least in USB).? If I leave the
VFO on 14.300 (while tuned in on the net control) and
turn on the 100KHz generator, I don't hear the tone at
all.? If I move the VFO down to 14.2986 (1.4KHz down), I
can zero-beat between USB and LSB there.? Shouldn't I be
able to zero beat between USB and LSB at 14.300 and hear
the net control on 14.300 at the same time?
Plus, you have to adjust the 500KHz back dial of the
VFO every time you switch from LSB, USB or CW...
relative to zeroing your market generator.?
