[Elecraft] K2's 4 MHZ Master Oscillator.

[Bob Wehking]

After I followed Wayne's procedure, I did do the CAL PLL & then CAL FIL for 
all the crystal filters.

Bob
WB8DDI


----- Original Message ----- 
From: "Don Wilhelm" <w3fpr at earthlink.net>
To: "Earl W Cunningham" <k6se at juno.com>; <rwehking at cinci.rr.com>; 
<Elecraft at mailman.qth.net>
Sent: Thursday, September 01, 2005 11:17 PM
Subject: RE: [Elecraft] K2's 4 MHZ Master Oscillator.


> Bob, Earl and folks,
>
> Earl's comments are correct, but CAL FIL must also be run before 
> calibration
> is complete.  Each BFO must be changed by at least one 'notch' and moved
> back to the same frequency (aqssuming the filters were properly set 
> before).
> The K2 must detect that each BFO has been changed because that is the only
> time new values are written to EEPROM.
>
> 73,
> Don W3FPR
>
> -----Original Message-----
>
> "I used Wayne Burdick's article to calibrate my K2. When I first tuned in
> WWV, the zero beat was at 9999.5. I adjusted c22 & measured  TP1(VCO) &
> TP2(BFO) until the two test points matched. Now WWV zero beats at
> 10000.5."
> ----------
> 500 Hz is a big error.  You can get it much closer.
> ==========
>
> "Should I have set my dial to 10000.00 & then adjusted C22?."
> ----------
> No!  Nothing will change until you do a CAL PLL after adjusting C22.
> ==========
> There are a number of methods of getting the 4000 kHz xtal oscillator on
> frequency by adjusting C22.  Without a frequency counter, one of the
> easiest is to tune in 20 MHz WWV on your IC-756Pro.  Use a short piece of
> flexible insulated wire for the antenna on the 756Pro and bring the end
> of that antenna near the 4 MHz oscillator in the K2.  You'll hear the 5th
> harmonic of the 4 MHZ oscillator beating with WWV (best to use the AM
> mode on the 756Pro and wait for those times when WWV is not transmitting
> a tone).  When you hear the heterodyne beat between the 5th harmonic of
> the K2's 4 MHz oscillator and 20 MHz WWV, adjust C22 to zero beat the
> heterodyne.
>
> Anytime you adjust C22, you must follow with a CAL PLL.  Then check your
> K2's frequency dial readout  accuracy.
>
> 73, de Earl, K6SE
>
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