[Elecraft] K1 on 80 meter 300 KHZ ?

[Mike Morrow]

Sandy wrote:


>Seems like that would work just fine!  Order a 2 band board
>with two "80 meter" options and you will have to get one custom crystal
>for your second segment.


There are two problems with that.

(1) The K1 can store in its MPU system only *one* LCD frequency display
calibration adjustment *per band*, so you could only calibrate the display
for one ot the two 80m bands on the board.

(2) The K1 FP MPU detects and counts only the VFO frequency, and not the
combined effects of the various hetrodyne crystals such as the one on the
filter board.  The MPU firmware makes certain assumptions on the frequency
span that is to be associated with each band and combines that with the
CAL-OPF display adjustment to display the correct operating frequency.  The
MPU firmware would need to be changed to properly display the band segments,
otherwise a custom filter board hetrodyne crystal installed to allow actual
coverage of, say, 3600 to 3750 kHz would still be displayed on the LCD as
3500 to 3650 kHz.

The only practical way to avoid *both* the above problems is to increase the
VFO range cap (RF-C2) above 120 pF until you get the desired VFO range.  If
that were 300 kHz, you'd have about a 30 kHz/turn of the VFO knob tuning
rate, AND you'd have the same wide span and high tuning rate on ALL the
other bands on your K1, no matter what filter boards was installed.

Personally, I've never been that much of a fan of 80m QRP.

73,
Mike / KK5F