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K2 C22 calibration

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K2 C22 calibration

Just completed assembly of my K2. The VFO display reads about 1.5KHz high. I've attempted several times to calibrate it by adjusting C22, but I'm not able to get the frequency of TP1 on the 30m band any lower than ~14.9154MHz (while the vfo set to zero beat with a 10MHz signal) without it causing the radio to stop responding.

When c22 is adjusted to a point where it lowers the frequency of TP1 below 14.915, the display freezes and it stops responding to button presses. If the power is cycled, no relays click and the display has no indication of life. When c22 is returned to the previous setting, the radio becomes responsive.

What should the next steps be?

Thanks,
--mark/ae0mm
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Don Wilhelm

Re: K2 C22 calibration

Mark,

The setting of C22 does not control the frequency readout directly. The
frequency readout uses the contents of the EEPROM that are produced when
you do the CAL PLL and CAL FIL procedures.

The only time C22 must be set correctly is just before you do a CAL PLL
or a CAL FIL. At other times it is just a clock for the MCU and does
not need to be accurate.

I suggest you read the K2 Dial Calibration article on my website
www.w3fpr.com and proceed according to those instructions.

73,
Don W3FPR

On 9/18/2018 9:27 PM, AE0MM via Elecraft wrote:
> Just completed assembly of my K2. The VFO display reads about 1.5KHz high. I've attempted several times to calibrate it by adjusting C22, but I'm not able to get the frequency of TP1 on the 30m band any lower than ~14.9154MHz (while the vfo set to zero beat with a 10MHz signal) without it causing the radio to stop responding.
>
> When c22 is adjusted to a point where it lowers the frequency of TP1 below 14.915, the display freezes and it stops responding to button presses. If the power is cycled, no relays click and the display has no indication of life. When c22 is returned to the previous setting, the radio becomes responsive.
>
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Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
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Elecraft mailing list

Re: K2 C22 calibration

Don,

Where I'm getting stuck is step one under SETTING THE K2 REFERENCE OSCILLATOR on this page:
http://www.w3fpr.com/dial_cal.html

Then step two on this page:
http://www.w3fpr.com/n6kr_method.htm

For a 10MHz reference, I'm unable to get the difference between TP1 (VCO) and TP2 (BFO) any closer than 10001.50. Attempts to get the difference of the VCO and BFO closer to 10000 result in radio becoming unresponsive.

Thanks,
--mark/ae0mm

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On 19 September 2018 6:59 AM, Don Wilhelm <[hidden email]> wrote:

> Mark,
>
> The setting of C22 does not control the frequency readout directly. The
> frequency readout uses the contents of the EEPROM that are produced when
> you do the CAL PLL and CAL FIL procedures.
>
> The only time C22 must be set correctly is just before you do a CAL PLL
> or a CAL FIL. At other times it is just a clock for the MCU and does
> not need to be accurate.
>
> I suggest you read the K2 Dial Calibration article on my website
> www.w3fpr.com and proceed according to those instructions.
>
> 73,
> Don W3FPR
>
> On 9/18/2018 9:27 PM, AE0MM via Elecraft wrote:
>
> > Just completed assembly of my K2. The VFO display reads about 1.5KHz high. I've attempted several times to calibrate it by adjusting C22, but I'm not able to get the frequency of TP1 on the 30m band any lower than ~14.9154MHz (while the vfo set to zero beat with a 10MHz signal) without it causing the radio to stop responding.
> > When c22 is adjusted to a point where it lowers the frequency of TP1 below 14.915, the display freezes and it stops responding to button presses. If the power is cycled, no relays click and the display has no indication of life. When c22 is returned to the previous setting, the radio becomes responsive.

______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
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Don Wilhelm

Re: K2 C22 calibration

Mark,

It sounds like you may be tuning to WWV using CW mode. CW mode uses a
receive offset equal to your sidetone pitch which can cause you to be in
error by twice the sidetone pitch.

What mode are you using when you tune WWV? It must be SSB, and you must
tune the transmitted tones correctly (do not tune to the carrier). 500
and 600 Hz tones are sent on alternating minutes except for announcement
and silent minutes. A 1000 Hz tone is sent for 1 second at the
beginning of each minute. Make certain you are hearing the tones at the
correct audio frequency.
An audio spectrum analyzer running on your computer can be very helpful,
or set a receiver capable of receiving in AM mode to tune WWV as well as
the K2 and match the audio tones.

73,
Don W3FPR

On 9/19/2018 9:19 AM, AE0MM wrote:

> Don,
>
>
> Where I'm getting stuck is step one under SETTING THE K2 REFERENCE OSCILLATOR on this page:
> http://www.w3fpr.com/dial_cal.html
>
> Then step two on this page:
> http://www.w3fpr.com/n6kr_method.htm
>
> For a 10MHz reference, I'm unable to get the difference between TP1 (VCO) and TP2 (BFO) any closer than 10001.50. Attempts to get the difference of the VCO and BFO closer to 10000 result in radio becoming unresponsive.
>
> Thanks,
> --mark/ae0mm
>
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On 19 September 2018 6:59 AM, Don Wilhelm <[hidden email]> wrote:
>
>> Mark,
>>
>> The setting of C22 does not control the frequency readout directly. The
>> frequency readout uses the contents of the EEPROM that are produced when
>> you do the CAL PLL and CAL FIL procedures.
>>
>> The only time C22 must be set correctly is just before you do a CAL PLL
>> or a CAL FIL. At other times it is just a clock for the MCU and does
>> not need to be accurate.
>>
>> I suggest you read the K2 Dial Calibration article on my website
>> www.w3fpr.com and proceed according to those instructions.
>>
>> 73,
>> Don W3FPR
>>
>> On 9/18/2018 9:27 PM, AE0MM via Elecraft wrote:
>>
>>> Just completed assembly of my K2. The VFO display reads about 1.5KHz high. I've attempted several times to calibrate it by adjusting C22, but I'm not able to get the frequency of TP1 on the 30m band any lower than ~14.9154MHz (while the vfo set to zero beat with a 10MHz signal) without it causing the radio to stop responding.
>>> When c22 is adjusted to a point where it lowers the frequency of TP1 below 14.915, the display freezes and it stops responding to button presses. If the power is cycled, no relays click and the display has no indication of life. When c22 is returned to the previous setting, the radio becomes responsive.
>

Elecraft mailing list

Re: K2 C22 calibration

I'm using the XG3. Attempts with both cw and usb mode have resulted in similar 1.5KHz to 2KHz differences in frequency display vs the output signal of the XG3. There is so much utility noise (arcing) at my QTH that hearing WWV can be difficult.

Why doesn't the receive offset, when zero-beating using the spot tone, result in the correct VFO offset? Seems I'm generally confused about dial frequency in ssb and cw.

I'll re-read everything again. It seems I'm wrongly assuming that zero-beating using a 600Hz tone would result in the dial frequency being off by -600Hz in usb. Tonight I'll use a spectrum analyzer and attempt dial calibration.

Thanks,
--mark/ae0mm

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On 19 September 2018 8:57 AM, Don Wilhelm <[hidden email]> wrote:

> Mark,
>
> It sounds like you may be tuning to WWV using CW mode. CW mode uses a
> receive offset equal to your sidetone pitch which can cause you to be in
> error by twice the sidetone pitch.
>
> What mode are you using when you tune WWV? It must be SSB, and you must
> tune the transmitted tones correctly (do not tune to the carrier). 500
> and 600 Hz tones are sent on alternating minutes except for announcement
> and silent minutes. A 1000 Hz tone is sent for 1 second at the
> beginning of each minute. Make certain you are hearing the tones at the
> correct audio frequency.
> An audio spectrum analyzer running on your computer can be very helpful,
> or set a receiver capable of receiving in AM mode to tune WWV as well as
> the K2 and match the audio tones.
>
> 73,
> Don W3FPR
>
> On 9/19/2018 9:19 AM, AE0MM wrote:
>
> > Don,
> > Where I'm getting stuck is step one under SETTING THE K2 REFERENCE OSCILLATOR on this page:
> > http://www.w3fpr.com/dial_cal.html
> > Then step two on this page:
> > http://www.w3fpr.com/n6kr_method.htm
> > For a 10MHz reference, I'm unable to get the difference between TP1 (VCO) and TP2 (BFO) any closer than 10001.50. Attempts to get the difference of the VCO and BFO closer to 10000 result in radio becoming unresponsive.
> > Thanks,
> > --mark/ae0mm
> > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > On 19 September 2018 6:59 AM, Don Wilhelm [hidden email] wrote:
> >
> > > Mark,
> > > The setting of C22 does not control the frequency readout directly. The
> > > frequency readout uses the contents of the EEPROM that are produced when
> > > you do the CAL PLL and CAL FIL procedures.
> > > The only time C22 must be set correctly is just before you do a CAL PLL
> > > or a CAL FIL. At other times it is just a clock for the MCU and does
> > > not need to be accurate.
> > > I suggest you read the K2 Dial Calibration article on my website
> > > www.w3fpr.com and proceed according to those instructions.
> > > 73,
> > > Don W3FPR
> > > On 9/18/2018 9:27 PM, AE0MM via Elecraft wrote:
> > >
> > > > Just completed assembly of my K2. The VFO display reads about 1.5KHz high. I've attempted several times to calibrate it by adjusting C22, but I'm not able to get the frequency of TP1 on the 30m band any lower than ~14.9154MHz (while the vfo set to zero beat with a 10MHz signal) without it causing the radio to stop responding.
> > > > When c22 is adjusted to a point where it lowers the frequency of TP1 below 14.915, the display freezes and it stops responding to button presses. If the power is cycled, no relays click and the display has no indication of life. When c22 is returned to the previous setting, the radio becomes responsive.

Don Wilhelm

Re: K2 C22 calibration

Mark,

If you are trying to use a single signal, you must do it a bit
differently. look at
http://w3fpr.com/Using%20RWM%20instead%20of%20WWV.htm and substitute the
frequency of your generator for the frequency of the carrier only
standard station - RWM.

Has your XG3 been calibrated for frequency? It is not a precision
frequency standard.

The K2 dial frequency is always the frequency of the transmitted carrier
(or suppressed carrier for SSB).
In CW, the receive frequency is offset by the amount of your sidetone so
you hear the signal at your selected sidetone pitch.

Make certain you have the filters on the right sideband. If you have
them correct, the DAC values for LSB, RTTY, and CW will be lower than
the DAC values for USB, RTTYrev, and CWrev (bar over the "r" or "c").

If you have the wrong sideband, the error will be twice the sidetone pitch.

73,
Don W3FPR

On 9/19/2018 12:04 PM, AE0MM wrote:

> I'm using the XG3. Attempts with both cw and usb mode have resulted in similar 1.5KHz to 2KHz differences in frequency display vs the output signal of the XG3. There is so much utility noise (arcing) at my QTH that hearing WWV can be difficult.
>
> Why doesn't the receive offset, when zero-beating using the spot tone, result in the correct VFO offset? Seems I'm generally confused about dial frequency in ssb and cw.
>
> I'll re-read everything again. It seems I'm wrongly assuming that zero-beating using a 600Hz tone would result in the dial frequency being off by -600Hz in usb. Tonight I'll use a spectrum analyzer and attempt dial calibration.
>
>
>
> Thanks,
> --mark/ae0mm
>
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On 19 September 2018 8:57 AM, Don Wilhelm <[hidden email]> wrote:
>
>> Mark,
>>
>> It sounds like you may be tuning to WWV using CW mode. CW mode uses a
>> receive offset equal to your sidetone pitch which can cause you to be in
>> error by twice the sidetone pitch.
>>
>> What mode are you using when you tune WWV? It must be SSB, and you must
>> tune the transmitted tones correctly (do not tune to the carrier). 500
>> and 600 Hz tones are sent on alternating minutes except for announcement
>> and silent minutes. A 1000 Hz tone is sent for 1 second at the
>> beginning of each minute. Make certain you are hearing the tones at the
>> correct audio frequency.
>> An audio spectrum analyzer running on your computer can be very helpful,
>> or set a receiver capable of receiving in AM mode to tune WWV as well as
>> the K2 and match the audio tones.
>>
>> 73,
>> Don W3FPR
>>
>> On 9/19/2018 9:19 AM, AE0MM wrote:
>>
>>> Don,
>>> Where I'm getting stuck is step one under SETTING THE K2 REFERENCE OSCILLATOR on this page:
>>> http://www.w3fpr.com/dial_cal.html
>>> Then step two on this page:
>>> http://www.w3fpr.com/n6kr_method.htm
>>> For a 10MHz reference, I'm unable to get the difference between TP1 (VCO) and TP2 (BFO) any closer than 10001.50. Attempts to get the difference of the VCO and BFO closer to 10000 result in radio becoming unresponsive.
>>> Thanks,
>>> --mark/ae0mm
>>> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
>>> On 19 September 2018 6:59 AM, Don Wilhelm [hidden email] wrote:
>>>
>>>> Mark,
>>>> The setting of C22 does not control the frequency readout directly. The
>>>> frequency readout uses the contents of the EEPROM that are produced when
>>>> you do the CAL PLL and CAL FIL procedures.
>>>> The only time C22 must be set correctly is just before you do a CAL PLL
>>>> or a CAL FIL. At other times it is just a clock for the MCU and does
>>>> not need to be accurate.
>>>> I suggest you read the K2 Dial Calibration article on my website
>>>> www.w3fpr.com and proceed according to those instructions.
>>>> 73,
>>>> Don W3FPR
>>>> On 9/18/2018 9:27 PM, AE0MM via Elecraft wrote:
>>>>
>>>>> Just completed assembly of my K2. The VFO display reads about 1.5KHz high. I've attempted several times to calibrate it by adjusting C22, but I'm not able to get the frequency of TP1 on the 30m band any lower than ~14.9154MHz (while the vfo set to zero beat with a 10MHz signal) without it causing the radio to stop responding.
>>>>> When c22 is adjusted to a point where it lowers the frequency of TP1 below 14.915, the display freezes and it stops responding to button presses. If the power is cycled, no relays click and the display has no indication of life. When c22 is returned to the previous setting, the radio becomes responsive.
>

Elecraft mailing list

Re: K2 C22 calibration

Don is incredible! He always knows when something is amiss. My K2 became unresponsive while adjusting c22 because I managed to swap c7 and c21 capacitors on the control board during assembly.

And yes, I did need to read up on zero-beating using sideband, not cw mode.

Thanks again, Don.

--ae0mm

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Wednesday, September 19, 2018 1:10 PM, Don Wilhelm <[hidden email]> wrote:

> Mark,
>
> If you are trying to use a single signal, you must do it a bit
> differently. look at
> http://w3fpr.com/Using RWM instead of WWV.htm and substitute the
> frequency of your generator for the frequency of the carrier only
> standard station - RWM.
>
> Has your XG3 been calibrated for frequency? It is not a precision
> frequency standard.
>
> The K2 dial frequency is always the frequency of the transmitted carrier
> (or suppressed carrier for SSB).
> In CW, the receive frequency is offset by the amount of your sidetone so
> you hear the signal at your selected sidetone pitch.
>
> Make certain you have the filters on the right sideband. If you have
> them correct, the DAC values for LSB, RTTY, and CW will be lower than
> the DAC values for USB, RTTYrev, and CWrev (bar over the "r" or "c").
>
> If you have the wrong sideband, the error will be twice the sidetone pitch.
>
> 73,
> Don W3FPR
>
> On 9/19/2018 12:04 PM, AE0MM wrote:
>
> > I'm using the XG3. Attempts with both cw and usb mode have resulted in similar 1.5KHz to 2KHz differences in frequency display vs the output signal of the XG3. There is so much utility noise (arcing) at my QTH that hearing WWV can be difficult.
> > Why doesn't the receive offset, when zero-beating using the spot tone, result in the correct VFO offset? Seems I'm generally confused about dial frequency in ssb and cw.
> > I'll re-read everything again. It seems I'm wrongly assuming that zero-beating using a 600Hz tone would result in the dial frequency being off by -600Hz in usb. Tonight I'll use a spectrum analyzer and attempt dial calibration.
> > Thanks,
> > --mark/ae0mm
> > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > On 19 September 2018 8:57 AM, Don Wilhelm [hidden email] wrote:
> >
> > > Mark,
> > > It sounds like you may be tuning to WWV using CW mode. CW mode uses a
> > > receive offset equal to your sidetone pitch which can cause you to be in
> > > error by twice the sidetone pitch.
> > > What mode are you using when you tune WWV? It must be SSB, and you must
> > > tune the transmitted tones correctly (do not tune to the carrier). 500
> > > and 600 Hz tones are sent on alternating minutes except for announcement
> > > and silent minutes. A 1000 Hz tone is sent for 1 second at the
> > > beginning of each minute. Make certain you are hearing the tones at the
> > > correct audio frequency.
> > > An audio spectrum analyzer running on your computer can be very helpful,
> > > or set a receiver capable of receiving in AM mode to tune WWV as well as
> > > the K2 and match the audio tones.
> > > 73,
> > > Don W3FPR
> > > On 9/19/2018 9:19 AM, AE0MM wrote:
> > >
> > > > Don,
> > > > Where I'm getting stuck is step one under SETTING THE K2 REFERENCE OSCILLATOR on this page:
> > > > http://www.w3fpr.com/dial_cal.html
> > > > Then step two on this page:
> > > > http://www.w3fpr.com/n6kr_method.htm
> > > > For a 10MHz reference, I'm unable to get the difference between TP1 (VCO) and TP2 (BFO) any closer than 10001.50. Attempts to get the difference of the VCO and BFO closer to 10000 result in radio becoming unresponsive.
> > > > Thanks,
> > > > --mark/ae0mm
> > > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > > > On 19 September 2018 6:59 AM, Don Wilhelm [hidden email] wrote:
> > > >
> > > > > Mark,
> > > > > The setting of C22 does not control the frequency readout directly. The
> > > > > frequency readout uses the contents of the EEPROM that are produced when
> > > > > you do the CAL PLL and CAL FIL procedures.
> > > > > The only time C22 must be set correctly is just before you do a CAL PLL
> > > > > or a CAL FIL. At other times it is just a clock for the MCU and does
> > > > > not need to be accurate.
> > > > > I suggest you read the K2 Dial Calibration article on my website
> > > > > www.w3fpr.com and proceed according to those instructions.
> > > > > 73,
> > > > > Don W3FPR
> > > > > On 9/18/2018 9:27 PM, AE0MM via Elecraft wrote:
> > > > >
> > > > > > Just completed assembly of my K2. The VFO display reads about 1.5KHz high. I've attempted several times to calibrate it by adjusting C22, but I'm not able to get the frequency of TP1 on the 30m band any lower than ~14.9154MHz (while the vfo set to zero beat with a 10MHz signal) without it causing the radio to stop responding.
> > > > > > When c22 is adjusted to a point where it lowers the frequency of TP1 below 14.915, the display freezes and it stops responding to button presses. If the power is cycled, no relays click and the display has no indication of life. When c22 is returned to the previous setting, the radio becomes responsive.