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

[Masleid, Michael A.]

Hello Nigel,

>Subject: [Elecraft] N6KR's 4 MHz oscillator cal method for the K2 -
>Query

>I had a mixed outcome with this method and have a query.
>Question.  Is it essential to run PLL on 40m AND CW normal AND FL1?

CAL PLL must be run on 40 meters.
I don't think the mode and filter matter.

On recent K2s, setting the 4 MHz oscillator to exactly 4 MHz and
running CAL PLL and CAL FLTR will usually result in WWV coming in at
9999.96 or 9999.97 kHz on the dial.

Setting the 4 MHz oscillator using CAL FCTR using N6KR's method or
by setting it with a frequency standard will result in WWV coming in
at 10000.01 or 10000.02 kHz on the dial.

Your results are very close to that.  The odd result at 9999.50 might
be due to trying to get zero beat while WWV is broadcasting an audio =
tone.
The 500 Hz error is consistent with zero beat on the audio sideband.

Your final result is the expected value - the error is 1 part per =
million.
Not too bad.

If you want to get closer than that, it looks like you can do it
if you set the 4 MHz oscillator to exactly 3999986.7 Hz, or else,
get a frequency reference at 28,100,000.0 MHz, and then adjust
CAL FCTR to show 28099.96 on the display, then run CAL PLL and
CAL FCTR.  By that point, issues like PLL temperature compensation
and crystal aging start to become important.

73, de Michael, AB9GV