[Elecraft] K1 VFO/Band assignment problems

[Mike Morrow]

Emil Tillona wrote:


> Ran into my first problem with my progress so far.  Initial range of VFO
is
> 3.141 fully Clockwise and 3.235 counter clockwise.  The range is 94 kHz
> which would seem to me to be in the ball park (C2 set for 80 kHz)

Opted for the 80 kHz spread after all, I see, and 17m vs. 15m.  Listening to
the 15m band opening yesterday made me glad I used the 170 kHz option and 15
m.  There were actually CW QSOs above 21110 kHz in progress.

> Next step is to rotate VFO knob full counter-clockwise which brings me to
> the 3.235 reading.  The reading is suppose to be between 3.090 and 3.100
> kHz.  Do I have too many turns on L1?

You may have too FEW turns, but you should try turn compression first, as
explained below.

The receiver frequency is equal to the hetrodyne crystal frequency (on
filter board) minus the IF frequency minus the VFO frequency.

Note that the VFO frequency is subtractive, so a higher VFO output frequency
results in a lower receiver frequency of operation.

Assuming for the sake of discussion that your 40m hetrodyne crystal is
exactly 15000 kHz, and your IF frequency is exactly 4913 kHz (but they won't
be exactly that), then a VFO frequency of 3087 kHz would result in a
receiver frequency of 7000 kHz, and a VFO frequency of 3007 kHz would result
in 7080 kHz.  So your VFO output frequency needs to run in the ballpark of
3000 (at high end of band)to 3090 (at low end of band) kHz.

Substituting your current VFO values, when your VFO is at 3141, the receiver
is at 6946 kHz, and when at 3.235, receiver is at 6.852 kHz.

> Don't think I can spread out enough to get to 3.090/.100.

Spreading turns RAISES the frequency of the VFO.

You need to LOWER your VFO frequency.  Try compressing turns on the VFO coil
L1 until you get the VFO range of 3000 to 3090 kHz or so.  If that fails,
you may need to add turns, but I think compressing turns will work fine for
you.

> Next.. I have the KFL1-4 Module.  On B1, B2, B3, B4 I set the assignments
> to 7.0, 10.1, 14.0, and 18.0.  ... When I exit the Menu and step through
the
> band assignments as a test, I get the following, which makes no sense to
> me.  6, 9, 13, 17.

What you see is perfectly normal for your VFO frequency being so HIGH out of
spec.  That makes the frequency of operation LOW, hence you aare seeing
frequencies below the desired ham bands displayed.  Correct the VFO range
and you'll be OK.

BTW, since the exact IF frequency and hetrodyne crystal frequency vary from
unit to unit, you'll use the display calibration function to correct the LCD
display.  I like to set my LCD display to show the transmitter frequency,
which will be below the receiver frequency by the amount of transmit offset
you've made with the RF board C13 trimmer.

Also, BTW, the K1 MCU measures only the raw VFO frequency, then displays the
effective value based on your band assignments and the display calibration
factor you'll set for each band.

73,
Mike / KK5F