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K2 dial alignment

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paul-292

K2 dial alignment

Hi,

Recently I started to upgrade my K2 (sn 2592) with the KPA100 kit. Before
I could complete the KPA100 though, I had to upgrade the K2 from rev A to
rev B. I have completed all the revs except for the firmware upgrade -
Elecraft sent only the MCU but not the IOC. It is now being mailed.

Before the rev, the frequency on the dial matched the received frequency.
Now WWV is received on 10.012 MHz. I have done the calibration of the 4MHz
several times - checking with a known good receiver (AOR AR7030+). I can
vary the c22 and zero beat exactly on frequency (USB and LSB) - also at
higher harmonics (16Mhz). I ran an antenna wire next to the 4MHz xtal and
listen on the SW receiver.

After the 4MHz calibration, I have run the CAL PLL and then modified every
CAL FIL entry afterwards. Still no change. The dial reads 7.010Mhz when
hearing 7MHZ and 14.020Mhz when hearing 14Mhz.

Otherwise, the receiver is excellent - much better than before. Had a low
volume problem before, now it is really loud. Did all the RF and contol
board changes, BFO temp stability mod, PLL upgrade, AF gain smoothness,
VFO ALC 10/12 meter band pass filter, AGC threshold (R1 from 51k to
22.5k). I have checked for bad solder joints or bridges - nothing wrong
that I can see.

I did not do the second crystal filer flatness mod or the sidetone mod
yet. Also no firmware had been changed yet. Any ideas what to check?

Thanks,

Paul
AD5IW

Here are some measurements when receiving 10MHz WWV:

TP3 14913.05
TP2 4913.19
TP1 12089.38

Dial: 10011.99

-------------------Range measurements
PLL
min: 12083.69
max: 12094.29
range: 10.60

TP3
min: 14906.04
max: 14919.09
range: 13.05

BFO
min: 4916.99
max: 4912.59
range: 4.40

R30: 4.34V 10MHz
5.70V @ 4MHZ
2.02V @ 3.5Mhz
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dave.wilburn

Re: K2 dial alignment

I like to use Spectrogram, and setup markers for 500 & 600 Hz, these are
the tones most often heard on WWV, and then use that to zero beat WWV.
With that setup I was able to get down to where I was 9.997 or 8 for the
10 Khz WWV signal.
-

David Wilburn
[hidden email]
K4DGW
K2 S/N 5982

On Sun, 2007-12-02 at 19:04 -0600, paul wrote:

> Hi,
>
> Recently I started to upgrade my K2 (sn 2592) with the KPA100 kit. Before
> I could complete the KPA100 though, I had to upgrade the K2 from rev A to
> rev B. I have completed all the revs except for the firmware upgrade -
> Elecraft sent only the MCU but not the IOC. It is now being mailed.
>
> Before the rev, the frequency on the dial matched the received frequency.
> Now WWV is received on 10.012 MHz. I have done the calibration of the 4MHz
> several times - checking with a known good receiver (AOR AR7030+). I can
> vary the c22 and zero beat exactly on frequency (USB and LSB) - also at
> higher harmonics (16Mhz). I ran an antenna wire next to the 4MHz xtal and
> listen on the SW receiver.
>
> After the 4MHz calibration, I have run the CAL PLL and then modified every
> CAL FIL entry afterwards. Still no change. The dial reads 7.010Mhz when
> hearing 7MHZ and 14.020Mhz when hearing 14Mhz.
>
> Otherwise, the receiver is excellent - much better than before. Had a low
> volume problem before, now it is really loud. Did all the RF and contol
> board changes, BFO temp stability mod, PLL upgrade, AF gain smoothness,
> VFO ALC 10/12 meter band pass filter, AGC threshold (R1 from 51k to
> 22.5k). I have checked for bad solder joints or bridges - nothing wrong
> that I can see.
>
> I did not do the second crystal filer flatness mod or the sidetone mod
> yet. Also no firmware had been changed yet. Any ideas what to check?
>
> Thanks,
>
> Paul
> AD5IW
>
> Here are some measurements when receiving 10MHz WWV:
>
> TP3 14913.05
> TP2 4913.19
> TP1 12089.38
>
> Dial: 10011.99
>
> -------------------Range measurements
> PLL
> min: 12083.69
> max: 12094.29
> range: 10.60
>
> TP3
> min: 14906.04
> max: 14919.09
> range: 13.05
>
> BFO
> min: 4916.99
> max: 4912.59
> range: 4.40
>
> R30: 4.34V 10MHz
> 5.70V @ 4MHZ
> 2.02V @ 3.5Mhz
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
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>
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Don Wilhelm-4

Re: K2 dial alignment

In reply to this post by paul-292

Paul,

The exact frequency of the 4 MHz (nominal) reference oscillator may be
slightly different than exactly 4 MHz.

If you have a well calibrated external frequency counter, you can adjust
the 4 MHz reference (adjust C22) by measuring the frequency at TP1 with
both the internal counter and the external counter - adjust C22 until
the internal counter reads the same as the external counter.

Another method that provides even greater accuracy is the method
outlined on the Elecraft website on the Builder's Resource page -
http://www.elecraft.com/Apps/K2%20C22%20Adjust%20App%20Note.pdf.
This method requires no extra calibrated equipment, but there is a
requirement that the standard station be tuned with precision. When
using WWV, I use Spectrogram to observe the audio output tones, knowing
that WWV transmits tones of 500 and 600 Hz on alternate minutes (there
are silent minutes and one minute of 440 Hz tone as well). If the tones
line up with my Spectrogram markers at 500 and 600 Hz, I know that WWV
is properly tuned within one or two Hz.

After setting the 4 MHz reference, run CAL PLL and CAL FIL changing each
BFO and the resulting frequency should be within 20 Hz of the correct
dial reading.

For more information, please refer to my website article on K2 Dial
Calibration www.qsl.net/w3fpr

73,
Don W3FPR

paul wrote:

paul-292

Re: K2 dial alignment

Hi Don,

I have read your website (and 50+ posts) and done this procedure about 5
times over the last 3 days - each time with the same result (no change).

Followed a procedure that made the two frequencies (TP3 and TP2)
exactly 10MHz apart by varying C22. Ran CAL PLL (7.1 Mhz) and then ran
CAL FIL. Made small changes to each BFO frequency on all modes
(USB,LSB,CW,/CW) and Xtal selections. No change at all - WWV is still at
10.012 MHz. WWV voice is perfectly tuned in both USB and LSB.

Right now the radio works great except for this problem. Guess I will try
again when I get the new firmware.

Thanks for your help,

Paul
AD5IW

On Mon, 3 Dec 2007, Don Wilhelm wrote:

> Paul,
>
> The exact frequency of the 4 MHz (nominal) reference oscillator may be
> slightly different than exactly 4 MHz.
> If you have a well calibrated external frequency counter, you can adjust the 4
> MHz reference (adjust C22) by measuring the frequency at TP1 with both the
> internal counter and the external counter - adjust C22 until the internal
> counter reads the same as the external counter.
>
> Another method that provides even greater accuracy is the method outlined on
> the Elecraft website on the Builder's Resource page -
> http://www.elecraft.com/Apps/K2%20C22%20Adjust%20App%20Note.pdf.
> This method requires no extra calibrated equipment, but there is a requirement
> that the standard station be tuned with precision. When using WWV, I use
> Spectrogram to observe the audio output tones, knowing that WWV transmits
> tones of 500 and 600 Hz on alternate minutes (there are silent minutes and one
> minute of 440 Hz tone as well). If the tones line up with my Spectrogram
> markers at 500 and 600 Hz, I know that WWV is properly tuned within one or two
> Hz.
>
> After setting the 4 MHz reference, run CAL PLL and CAL FIL changing each BFO
> and the resulting frequency should be within 20 Hz of the correct dial
> reading.
>
> For more information, please refer to my website article on K2 Dial
> Calibration www.qsl.net/w3fpr
>
> 73,
> Don W3FPR
>

Don Wilhelm-4

Re: K2 dial alignment

Paul,

Your original post had the BFO at 4913.19 kHz and the VFO at 14913.05
when receiving 10 MHz WWV. Clearly the difference is not 10 MHz, and
that indicates that C22 was not properly adjusted.

Briefly, the procedure is:
NOTE: The K2 must be in LSB or USB mode - not CW.
1) Tune WWV precisely (ignoring the dial reading)
2) Adjust C22 until the BFO and VFO are different by the frequency of
WWV (10 MHz for 10 MHz WWV - the low order digits should match exactly.
3) Switch to 40 meters and run CAL PLL
4) CHANGE each BFO setting to force the K2 to record new DAC values in
EEPROM.
5) Check the results by tuning WWV again - the dial reading should be
correct.

You said you were following that procedure, but somewhere along the line
something has apparently gone wrong - the order of things is important
for this procedure to work properly. It works every time for me, and I
use it frequently.

Have you interchanged TP1 and TP3? - they were incorrectly labeled in
your original post. The frequency difference is observed between TP1
and TP2 - TP1 is located near T5 and TP2 is located below the KSB2 board
location (through access hole when the KSB2 is installed). TP3 is near
the front and is not used in this procedure - it is the PLL frequency
and will always be in the range of 12 MHz.
I suggest you simply try again.

73,
Don W3FPR

paul wrote:

> Hi Don,
>
> I have read your website (and 50+ posts) and done this procedure about 5
> times over the last 3 days - each time with the same result (no change).
>
> Followed a procedure that made the two frequencies (TP3 and TP2)
> exactly 10MHz apart by varying C22. Ran CAL PLL (7.1 Mhz) and then ran
> CAL FIL. Made small changes to each BFO frequency on all modes
> (USB,LSB,CW,/CW) and Xtal selections. No change at all - WWV is still at
> 10.012 MHz. WWV voice is perfectly tuned in both USB and LSB.
>
> Right now the radio works great except for this problem. Guess I will try
> again when I get the new firmware.
>
> Thanks for your help,
>
> Paul
> AD5IW
>
> On Mon, 3 Dec 2007, Don Wilhelm wrote:
>
>
>> Paul,
>>
>> The exact frequency of the 4 MHz (nominal) reference oscillator may be
>> slightly different than exactly 4 MHz.
>> If you have a well calibrated external frequency counter, you can adjust the 4
>> MHz reference (adjust C22) by measuring the frequency at TP1 with both the
>> internal counter and the external counter - adjust C22 until the internal
>> counter reads the same as the external counter.
>>
>> Another method that provides even greater accuracy is the method outlined on
>> the Elecraft website on the Builder's Resource page -
>> http://www.elecraft.com/Apps/K2%20C22%20Adjust%20App%20Note.pdf.
>> This method requires no extra calibrated equipment, but there is a requirement
>> that the standard station be tuned with precision. When using WWV, I use
>> Spectrogram to observe the audio output tones, knowing that WWV transmits
>> tones of 500 and 600 Hz on alternate minutes (there are silent minutes and one
>> minute of 440 Hz tone as well). If the tones line up with my Spectrogram
>> markers at 500 and 600 Hz, I know that WWV is properly tuned within one or two
>> Hz.
>>
>> After setting the 4 MHz reference, run CAL PLL and CAL FIL changing each BFO
>> and the resulting frequency should be within 20 Hz of the correct dial
>> reading.
>>
>> For more information, please refer to my website article on K2 Dial
>> Calibration www.qsl.net/w3fpr
>>
>> 73,
>> Don W3FPR
>>
>>
>
>
>

paul-292

Re: K2 dial alignment

In reply to this post by paul-292

Hi Don,

You are right that I interchanged TP1 and TP3 in my post but the
information was correct otherwise. While the orginal post did have a
difference of 9999.86 Khz instead of 10MHz, I have rerun the procedure
with an exact difference of 10MHz (by small adjustments in C22).

Last run:

TP1: 14913.28
TP2: 4913.28

When running CAL FIL (on 7MHz), I have changed the BFO frequency by 1 or
2 count and left it changed (to make sure). This was done on every mode and
xtal setting.

On a prior run, I also tried varying the bandwidth setting of each mode
and xtal - also no difference at all. Also tried to run CAL PLL on 10MHz
- results in error code. Same error code with CAL FIL on 10MHz.

All bands are off by at least 10khz.

7mhz reads +10khz
10mhz reads +12khz
14mhz reads +20khz

Just for grins, I have tried transmitting at 10Mhz (dial 10.012) into a
dummy load. SWL receiver hears it on 10MHz zero beating with WWV. I
have run spectragram software to adjust the filters and have checked the
filters by ear. It seems to work well - no weirdness. I have checked to
make sure the filter is on the correct side of the bandpass (7MHz) -
lower side for LSB,CW and high side for USB and /CW.

When listening to 10MHz WWV (dial 10.012MHZ), I can switch between USB and
LSB and the voice is perfectly tuned in on both settings.

Current MCU firmware is 2.02. Have the MCU 2.04 firmware, but not the
current IOC version. Now eagerly waiting for it! :)

Maybe I have done something stupid - just stumped for now.

Thanks for your help.

Paul
AD5IW

On Mon, 3 Dec 2007, Don Wilhelm wrote:

> Paul,
>
> Your original post had the BFO at 4913.19 kHz and the VFO at 14913.05
> when receiving 10 MHz WWV. Clearly the difference is not 10 MHz, and
> that indicates that C22 was not properly adjusted.
>
> Briefly, the procedure is:
> NOTE: The K2 must be in LSB or USB mode - not CW.
> 1) Tune WWV precisely (ignoring the dial reading)
> 2) Adjust C22 until the BFO and VFO are different by the frequency of WWV
> (10 MHz for 10 MHz WWV - the low order digits should match exactly.
> 3) Switch to 40 meters and run CAL PLL
> 4) CHANGE each BFO setting to force the K2 to record new DAC values in
> EEPROM.
> 5) Check the results by tuning WWV again - the dial reading should be
> correct.
>
> You said you were following that procedure, but somewhere along the line
> something has apparently gone wrong - the order of things is important
> for this procedure to work properly. It works every time for me, and I
> use it frequently.
>
> Have you interchanged TP1 and TP3? - they were incorrectly labeled in
> your original post. The frequency difference is observed between TP1 and
> TP2 - TP1 is located near T5 and TP2 is located below the KSB2 board
> location (through access hole when the KSB2 is installed). TP3 is near
> the front and is not used in this procedure - it is the PLL frequency and
> will always be in the range of 12 MHz.
> I suggest you simply try again.
>
> 73,
> Don W3FPR
>
> paul wrote:
>
> Hi Don,
>
> I have read your website (and 50+ posts) and done this procedure about 5
> times over the last 3 days - each time with the same result (no change).
>
> Followed a procedure that made the two frequencies (TP3 and TP2)
> exactly 10MHz apart by varying C22. Ran CAL PLL (7.1 Mhz) and then ran
> CAL FIL. Made small changes to each BFO frequency on all modes
> (USB,LSB,CW,/CW) and Xtal selections. No change at all - WWV is still at
> 10.012 MHz. WWV voice is perfectly tuned in both USB and LSB.
>
> Right now the radio works great except for this problem. Guess I will try
> again when I get the new firmware.
>
> Thanks for your help,
>
> Paul
> AD5IW
>
> On Mon, 3 Dec 2007, Don Wilhelm wrote:
>
>
>
> Paul,
>
> The exact frequency of the 4 MHz (nominal) reference oscillator may be
> slightly different than exactly 4 MHz.
> If you have a well calibrated external frequency counter, you can adjust the 4
> MHz reference (adjust C22) by measuring the frequency at TP1 with both the
> internal counter and the external counter - adjust C22 until the internal
> counter reads the same as the external counter.
>
> Another method that provides even greater accuracy is the method outlined on
> the Elecraft website on the Builder's Resource page -
> http://www.elecraft.com/Apps/K2%20C22%20Adjust%20App%20Note.pdf.
> This method requires no extra calibrated equipment, but there is a requirement
> that the standard station be tuned with precision. When using WWV, I use
> Spectrogram to observe the audio output tones, knowing that WWV transmits
> tones of 500 and 600 Hz on alternate minutes (there are silent minutes and one
> minute of 440 Hz tone as well). If the tones line up with my Spectrogram
> markers at 500 and 600 Hz, I know that WWV is properly tuned within one or two
> Hz.
>
> After setting the 4 MHz reference, run CAL PLL and CAL FIL changing each BFO
> and the resulting frequency should be within 20 Hz of the correct dial
> reading.
>
> For more information, please refer to my website article on K2 Dial
> Calibration www.qsl.net/w3fpr
>
> 73,
> Don W3FPR
>
>
>
>
>

Dan Barker

RE: K2 dial alignment

Are you talking about a dial reading of 10000.12 (120 Hz) or 10012.00
(12,000 Hz)? Most of us get the readings within plus or minus 30 Hz. 10 KHz
is way out of whack.

Confused in Atlanta

Dan / WG4S / K2 #2456 (Reads 10000.01 on WWV)

-----Original Message-----

All bands are off by at least 10khz.

7mhz reads +10khz
10mhz reads +12khz
14mhz reads +20khz

Just for grins, I have tried transmitting at 10Mhz (dial 10.012) into a
dummy load. SWL receiver hears it on 10MHz zero beating with WWV.

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dave.wilburn

RE: K2 dial alignment

Mine is 9999.98.
-

David Wilburn
[hidden email]
K4DGW
K2 S/N 5982

On Mon, 2007-12-03 at 14:14 -0500, Dan Barker wrote:

> Are you talking about a dial reading of 10000.12 (120 Hz) or 10012.00
> (12,000 Hz)? Most of us get the readings within plus or minus 30 Hz. 10 KHz
> is way out of whack.
>
> Confused in Atlanta
>
> Dan / WG4S / K2 #2456 (Reads 10000.01 on WWV)
>
> -----Original Message-----
>
>
> All bands are off by at least 10khz.
>
> 7mhz reads +10khz
> 10mhz reads +12khz
> 14mhz reads +20khz
>
> Just for grins, I have tried transmitting at 10Mhz (dial 10.012) into a
> dummy load. SWL receiver hears it on 10MHz zero beating with WWV.
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
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>
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> Elecraft web page: http://www.elecraft.com

David King-11

Elecraft Calendar?

In reply to this post by paul-292

With the excitement you guys are expressing about "Lisa Edition"
K3's...I can hear it now....when is Elecraft going to be issuing an
Elecraft Calendar?

With a different employee holding a different Elecraft product in each
month's picture?

Of course the December photo would be Wayne and Eric in Santa suits,
teasing us with wrapped boxes marked with question marks over what the
next goodies will be!!

David
KE7EKA
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M0XDF

Re: Elecraft Calendar?

That is actually a good idea, especially if the contests were marked on it
(please don't forget RSGB contests etc).

And if Elecraft have a favourite charity, half the proceeds could go there.

On 4/12/07 17:51, "David King" <[hidden email]> sent:

--
Patience serves as a protection against wrongs as clothes do against cold.
For if you put on more clothes as the cold increases, it will have no power
to hurt you.
So in like manner you must grow in patience when you meet with great wrongs,
and they will then be powerless to vex your mind.
-Leonardo da Vinci, painter, engineer, musician, and scientist (1452-1519)

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w6jd

Re: Elecraft Calendar?

In reply to this post by David King-11

Would there be a swim suit edition?

Doug
W6JD

-------------- Original message --------------
From: David King <[hidden email]>

> With the excitement you guys are expressing about "Lisa Edition"
> K3's...I can hear it now....when is Elecraft going to be issuing an
> Elecraft Calendar?
>
> With a different employee holding a different Elecraft product in each
> month's picture?
>
> Of course the December photo would be Wayne and Eric in Santa suits,
> teasing us with wrapped boxes marked with question marks over what the
> next goodies will be!!
>
> David
> KE7EKA
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
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>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

Julian, G4ILO

Re: Elecraft Calendar?

There should be topless models, of course. The radios, I mean, so we
can see the electronics. :)

(Bet this doesn't get past the spam filter.)
--
Julian, G4ILO K2 s/n: 392 K3 s/n: ???
G4ILO's Shack: www.g4ilo.com
Zerobeat Ham Forums: www.zerobeat.net/smf

On 04/12/2007, [hidden email] <[hidden email]> wrote:
> Would there be a swim suit edition?
>
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Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com
* KComm - http://www.g4ilo.com/kcomm.html
* KTune - http://www.g4ilo.com/ktune.html

Thom LaCosta

Re: Elecraft Calendar?

In reply to this post by David King-11

On Tue, 4 Dec 2007, David King wrote:

> Of course the December photo would be Wayne and Eric in Santa suits, teasing
> us with wrapped boxes marked with question marks over what the next goodies
> will be!!

Or the question marks could represent the serial numbers that are next due to
ship (g).

73 - k3hrn
Thom,EIEIO
Email, Internet, Electronic Information Officer

www.baltimorehon.com/ Home of the Baltimore Lexicon
www.tlchost.net/hosting/ Web Hosting as low as 3.49/month
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dj7mgq

Re: Elecraft Calendar?

In reply to this post by w6jd

> Would there be a swim suit edition?

A K3 in a g-string... come on...

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paul-292

K2 dial alignment SOLVED!!

In reply to this post by paul-292

Last year, I upgraded my K2 from rev A to Rev B. Afterwards the dial was
off by 12 KHz at 10MHz, even after setting the 4Mhz crystal, doing CAL
PLL, CAL FIL more than 30 times. Yes, I followed every procedure posted
and verified the 4 MHz clock accurately. Prior to the upgrade, the dial
was right on.

It turns out that the VCO max frequency must be at least 12096 khz or the
dial calibration will be off. This should be in the FAQ, along with how
to fix it in the upgrade instructions.

After making the rev A to B mod, the VCO range was 12084.87 to 19094.44
creating the 12Khz dial error - no matter how many alignments attempted.

Finally I just tried experimenting with the VCO. I put in another
crystal in parallel with X1 (that came with the BFO upgrade) in X2.
The VCO range was 12081.52 to 12098.17 which fixed the dial error, but
the VCO was too wide at 17.19 Khz.

I swapped out the 12uH inductor (L31) with the old 10uH inductor and got a
VCO range of 12084.87 to 12094.44 - dial calibration was way off (Yes, CAL
PLL and CAL FIL were run after each of these changes).

Then I removed the second crystal at X2 that I had temporarly installed
two steps above. VCO range now 12090.70 to 12097.63 - BINGO - the
dial is dead on!!! The VCO is a little narrow at 6.93 Khz, but I have no
plans to use 160 meters - so this should be ok.

So the solution was to go back to the 10uH inductor.

I have spent several weekends and nights trying to figure out this
problem. While I have learned a lot doing this, please put this in a FAQ
somewhere and save someone else the trouble.

Paul
AD5IW

On Sun, 2 Dec 2007, paul wrote:

> Hi,
>
> Recently I started to upgrade my K2 (sn 2592) with the KPA100 kit. Before
> I could complete the KPA100 though, I had to upgrade the K2 from rev A to
> rev B. I have completed all the revs except for the firmware upgrade -
> Elecraft sent only the MCU but not the IOC. It is now being mailed.
>
> Before the rev, the frequency on the dial matched the received frequency.
> Now WWV is received on 10.012 MHz. I have done the calibration of the 4MHz
> several times - checking with a known good receiver (AOR AR7030+). I can
> vary the c22 and zero beat exactly on frequency (USB and LSB) - also at
> higher harmonics (16Mhz). I ran an antenna wire next to the 4MHz xtal and
> listen on the SW receiver.
>
> After the 4MHz calibration, I have run the CAL PLL and then modified every
> CAL FIL entry afterwards. Still no change. The dial reads 7.010Mhz when
> hearing 7MHZ and 14.020Mhz when hearing 14Mhz.
>
> Otherwise, the receiver is excellent - much better than before. Had a low
> volume problem before, now it is really loud. Did all the RF and contol
> board changes, BFO temp stability mod, PLL upgrade, AF gain smoothness,
> VFO ALC 10/12 meter band pass filter, AGC threshold (R1 from 51k to
> 22.5k). I have checked for bad solder joints or bridges - nothing wrong
> that I can see.
>
> I did not do the second crystal filer flatness mod or the sidetone mod
> yet. Also no firmware had been changed yet. Any ideas what to check?
>
> Thanks,
>
> Paul
> AD5IW
>
> Here are some measurements when receiving 10MHz WWV:
>
> TP1 14913.05
> TP2 4913.19
> TP3 12089.38
>
> Dial: 10011.99
>
> -------------------Range measurements
> PLL
> min: 12083.69
> max: 12094.29
> range: 10.60
>
> TP1
> min: 14906.04
> max: 14919.09
> range: 13.05
>
> BFO
> min: 4916.99
> max: 4912.59
> range: 4.40
>
> R30: 4.34V 10MHz
> 5.70V @ 4MHZ
> 2.02V @ 3.5Mhz
>

Don Wilhelm-4

Re: K2 dial alignment SOLVED!!

Paul,

The A to B instructions do state that the PLL reference high frequency
is 'typically 12097 to 12100 kHz'.
Yours was clearly not in the typical range, and indicated that something
was awry.
You are correct that there should be a statement that the upper
frequency must be above 12096 kHz.

Incidently, a 12 uHy choke should provide a greater range than a 10
uHy. I am wondering if the 12 uHy choke you received was really a 12
uHy. I am certain it was marked as a 12 uHy - any chance that you can
measure it to see if my speculation is correct?

73,
Don W3FPR

paul wrote:

> Last year, I upgraded my K2 from rev A to Rev B. Afterwards the dial was
> off by 12 KHz at 10MHz, even after setting the 4Mhz crystal, doing CAL
> PLL, CAL FIL more than 30 times. Yes, I followed every procedure posted
> and verified the 4 MHz clock accurately. Prior to the upgrade, the dial
> was right on.
>
> It turns out that the VCO max frequency must be at least 12096 khz or the
> dial calibration will be off. This should be in the FAQ, along with how
> to fix it in the upgrade instructions.
>
> After making the rev A to B mod, the VCO range was 12084.87 to 19094.44
> creating the 12Khz dial error - no matter how many alignments attempted.
>
> Finally I just tried experimenting with the VCO. I put in another
> crystal in parallel with X1 (that came with the BFO upgrade) in X2.
> The VCO range was 12081.52 to 12098.17 which fixed the dial error, but
> the VCO was too wide at 17.19 Khz.
>
> I swapped out the 12uH inductor (L31) with the old 10uH inductor and got a
> VCO range of 12084.87 to 12094.44 - dial calibration was way off (Yes, CAL
> PLL and CAL FIL were run after each of these changes).
>
> Then I removed the second crystal at X2 that I had temporarly installed
> two steps above. VCO range now 12090.70 to 12097.63 - BINGO - the
> dial is dead on!!! The VCO is a little narrow at 6.93 Khz, but I have no
> plans to use 160 meters - so this should be ok.
>
> So the solution was to go back to the 10uH inductor.
>
> I have spent several weekends and nights trying to figure out this
> problem. While I have learned a lot doing this, please put this in a FAQ
> somewhere and save someone else the trouble.
>
> Paul
> AD5IW
>
> On Sun, 2 Dec 2007, paul wrote:
>
>

paul-292

Re: K2 dial alignment SOLVED!!

Hi Don,

The inductor I removed measures 12.9 uH - seems to be in tolerance. My
guess is the crystals (X1) had too high Q. I got two - one with the the
PLL temp compensation and one in the BFO upgrade. Tried each of the
crystals - both had the same dial error result.

You are right that instructions do say that, but I posted the results of
this test in my original post. The only messages I got were to set the 4
Mhz oscillator (using several different methods), run CAL PLL and CAL FIL
(vary each entry). None of this addressed the real issue.

I had installed the components correctly and I just could not understand
what went wrong. It ends up being a design flaw (component variation
exceeded the design parameters). Oh well, I learned a lot even though the
radio sat idle for a year. Can't contest or qsl much when you don't know
what frequency you really are on. :)

Another person on the list had the same problem and mentioned it in a
single post - which had no response or update to the FAQ list. That
post gave a hint that a slightly low VCO frequency was resposible for dial
error.

Don, I am not picking on you as you have provided help tirelessly to
hundreds of people on this list (and to me several times). Thank you.

All I am asking is that Elecraft update their FAQ to include this critical
info.

Thanks,
Paul
AD5IW

On Wed, 3 Dec 2008, Don Wilhelm wrote:

> Paul,
>
> The A to B instructions do state that the PLL reference high frequency is
> 'typically 12097 to 12100 kHz'.
> Yours was clearly not in the typical range, and indicated that something was
> awry.
> You are correct that there should be a statement that the upper frequency must
> be above 12096 kHz.
>
> Incidently, a 12 uHy choke should provide a greater range than a 10 uHy. I am
> wondering if the 12 uHy choke you received was really a 12 uHy. I am certain
> it was marked as a 12 uHy - any chance that you can measure it to see if my
> speculation is correct?
>
> 73,
> Don W3FPR
>
> paul wrote:
> > Last year, I upgraded my K2 from rev A to Rev B. Afterwards the dial was
> > off by 12 KHz at 10MHz, even after setting the 4Mhz crystal, doing CAL
> > PLL, CAL FIL more than 30 times. Yes, I followed every procedure posted
> > and verified the 4 MHz clock accurately. Prior to the upgrade, the dial
> > was right on.
> >
> > It turns out that the VCO max frequency must be at least 12096 khz or the
> > dial calibration will be off. This should be in the FAQ, along with how
> > to fix it in the upgrade instructions.
> >
> > After making the rev A to B mod, the VCO range was 12084.87 to 19094.44
> > creating the 12Khz dial error - no matter how many alignments attempted.
> >
> > Finally I just tried experimenting with the VCO. I put in another
> > crystal in parallel with X1 (that came with the BFO upgrade) in X2. The
> > VCO range was 12081.52 to 12098.17 which fixed the dial error, but the
> > VCO was too wide at 17.19 Khz.
> >
> > I swapped out the 12uH inductor (L31) with the old 10uH inductor and got
> > a VCO range of 12084.87 to 12094.44 - dial calibration was way off (Yes,
> > CAL PLL and CAL FIL were run after each of these changes).
> >
> > Then I removed the second crystal at X2 that I had temporarly installed
> > two steps above. VCO range now 12090.70 to 12097.63 - BINGO - the dial
> > is dead on!!! The VCO is a little narrow at 6.93 Khz, but I have no
> > plans to use 160 meters - so this should be ok.
> >
> > So the solution was to go back to the 10uH inductor.
> >
> > I have spent several weekends and nights trying to figure out this
> > problem. While I have learned a lot doing this, please put this in a FAQ
> > somewhere and save someone else the trouble.
> >
> > Paul
> > AD5IW
> >
> > On Sun, 2 Dec 2007, paul wrote:
> >
> >
>