[Elecraft] N6KR's 4 MHz oscillator cal method for the K2

[Don Wilhelm]

John,

It makes some sense in that I understand what you are saying, but I believe
it is also causing you some difficulty.  When the K2 is tuned (in LSB or
USB) to the correct carrier frequency, you should not hear any tone from the
carrier (the carrier should appear at zero hertz - which neither your ears
nor the K2 audio path can detect).  When you tune WWV so you can hear a tone
produced from the carrier, you are tuned not to 10 MHz, but to 10 MHz +/-
(audio tone).

CW is different - it is offset by the frequency of your sidetone pitch, so
if you must use a tone from the carrier, use CW and match the actual
received pitch to your sidetone pitch setting.

Tune the WWV signal (in LSB) first for a reasonable voice clarity - that
will get you close, then wait for the tones to be transmitted - you should
see the tones on the Spectrogram display as peaks on the Spectrogram display
(you have to wait for the Spectrogram display to 'catch up' - depends on
your resolution and computer speed - it takes about 7 seconds with my old
233 MHz computer).

Touch up the K2 VFO setting to get the peaks quite close to either 500 or
600 Hz, and you are right on.

The problem with tuning for the carrier at any specific pitch is that the K2
is no longer tuned to 10 MHz, but is offset by the amount of that pitch -
that means that your addition/subtraction task becomes complicated (the
received frequency = VFO +/- BFO).  Observing the pitch of the WWV tones
assures you that the K2 is listening to exactly 10 MHz, and all you have to
do with the counter is to adjust C22 (do not move the VFO) until the lower
digits match for both test points.  When they match, the two frequencies
will be 10 MHz apart - which is what you want.

73,
Don W3FPR

----- Original Message ----- 
|
| Like I said I am learning. I am running Spectrogram right now and I don't
| see the 500 and 600 tones on Spectrogram. I hear them, but they are
darwfed
| by what I believe is the carrier for WWV. Because zerobeating with SSB is
| different for each sideband what I think I am doing is matching the tone
of
| the carrier for both sidebands. My thinking is that when they match I
should
| be zeroed.
|