Tony K2MO asked:
I noticed that the VFO on my 4-band K1 doesn't tune above 14062 and
21061.0 yet it tunes to 7068.6 on 40 meters. The tuning range on 30
meters is 85 kHz (10077 to 10162) so I'm assuming the rig had the
smaller tuning range crystal installed. Tuning range on 40 meters is:
6986 to 7068.6.
So the question is: how can I shift the tuning range on 20 and 15 meters
so I can tune above 062 and 061 on 14 and 21 MHz? The current tuning
range is 13077 to 14062 on 20 meters and 20976 to 21061.0 on 15 meters.
********************
I recommend that you download the K1 manual if you don't have one for your rig:
https://ftp.elecraft.com/K1/Manuals%20Downloads/E740016%20K1%20manual%20rev%20J.pdf
On page 38 of this manual is the information that you need.
First, the size of the tuning range is set by the choice of capacitor C2 on the
RF board. This also affects the tuning rate and possibly the drift rate.
Second, the lower end of the tuning range is set by squeezing or spreading the
turns on the big toroid L1. I think that the VFO tunes backward (K1 output up
as VFO down), so you may want to squeeze the turns. But read the manual to be
sure. Keep in mind that page 38 of the manual is part of the assembly
instructions; you may need to remove some parts of the K1 (like the band
module) before adjusting L1. Or maybe you can tweak L1 a bit, then check the
effect on the K1's output frequencies and repeat.
Third, per-band differences in output frequencies result from differences in
the frequencies of the crystals on the band module from their nominal values.
I believe that these are unavoidable. If you want to cover the bottom edge of
each band, your measurements suggest that 40 meters is the band to watch. If
that's not a concern, you may be able to move the frequency coverages up more
than 14 kHz.
73, Paul W8TM
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