K2's 4 MHZ Master Oscillator.

[Bob Wehking]

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 .

Should I have set my dial to 10000.00 & then adjusted C22?.

I have also checked my calibration with my ICOM 756Pro &it also shows that I am off 500HZ based on WWV & other signals on 20 meters.

Bob
WB8DDI
K2# 4998
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[Matt Osborn]

On Thu, 1 Sep 2005 20:48:06 -0400, "Bob Wehking"
<[hidden email]> wrote:

>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 .
>
>Should I have set my dial to 10000.00 & then adjusted C22?.
>
>I have also checked my calibration with my ICOM 756Pro &it also shows that I am off 500HZ based on WWV & other signals on 20 meters.
>

I use HRD's PSK31 Deluxe to zero beat WWV.  The 100Hz signal is easily
seen and tuned within the capabilities of the K2, eliminating the
deceptive sound from mistuned filters.  Follow that by running CAL PLL
and CAL FIL will bring out the best in the K2.
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[Earl W Cunningham]

Bob, WB8DDI wrote:

"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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[Earl W Cunningham]

As I recall, after I built my K2 (more than three years ago), after the
first CAL PLL I was unhappy with its frequency dial accuracy ( it was 300
or 400 Hz of on 10 MHz WWV.

There are three different described in the K2 manual for adjusting C22.
I then used the one that measures two frequencies and you figure the
difference between the two frequencies and divide by 2.  Then the
procedure has you adjust C22 using this result and re-run CAL PLL.  This
brought 10 MHz WWV's frequency readout to within 10 Hz on my K2's dial.

I may be a bit off on this procedure (I'm writing this from memory), but
the procedure is in the manual, and it works!

73, de Earl, K6SE
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[Don Wilhelm-3]

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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[JEAN-FRANCOIS MENARD-3]

Also be sure to let the K2... at least... 15 minutes ON. It must  
warms itself.... Mine was set.. and when fresh turn on... 50Hz off...  
after 15 minutes or so.... maybe 10 to 20 Hz off only.


Le 05-09-01 à 23:17, Don Wilhelm a écrit :

> 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
>
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.344 / Virus Database: 267.10.18/88 - Release Date:  
> 9/1/2005
>
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[Ron D'Eau Claire-2]

Did you re-run CAL PLL and CAL FIL?

I used Wayne's procedure and found it very easy and it produced frequency
readouts well within the K2's DAC resolution - dead on at most points,
always with 20 Hz, and no other equipment required.

But you MUST run CAL PLL and also CAL FIL afterward to reset all the
frequencies. That's because all you are doing by adjusting C22 is to
calibrate the frequency counter that is used for setting everything else!

If you had you filters set to your satisfaction, all you have to do is to
force the K2 to re-read the BFO frequencies after you've finished with C22.
You do that by connecting the probe to your BFO test point, enabling CAL
FIL, then, for each filter and bandwidth, change the setting away from what
you had, then move it right back. The fact that you twiddled the dial causes
the K2 to "think" you changed things, even though you put it right back. So
then it'll re-read and store the BFO frequency using the newly-calibrated
frequency counter function (Cal Fctr) to give you better dial readings.

Ron AC7AC


-----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 .

Should I have set my dial to 10000.00 & then adjusted C22?.

I have also checked my calibration with my ICOM 756Pro &it also shows that I
am off 500HZ based on WWV & other signals on 20 meters.

Bob
WB8DDI
K2# 4998
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[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" <[hidden email]>
To: "Earl W Cunningham" <[hidden email]>; <[hidden email]>;
<[hidden email]>
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
>
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.344 / Virus Database: 267.10.18/88 - Release Date: 9/1/2005
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Anti-Virus.
> Version: 7.0.344 / Virus Database: 267.10.17/85 - Release Date: 8/30/2005
>

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