[Elecraft] K3 Frequency Calibration

[Joe Subich, W4TV]

I use WSJTX but not in its CAL mode.  Simply set the VFO for x.000 on
the highest frequency you can reliably hear WWV (10, 15, 20 or 25 MHz)
and "dial in" the audio tone (SSB or DATA A) to the proper 500/600 Hz
frequency using REF CAL.

I've stopped using the "toggle between USB/LSB or CW/CW_R" and match
the tone as it's far easier to set the trace on the waterfall -
particularly if one sets "bins per pixel" to 1.

73,

    ... Joe, W4TV


On 2021-12-19 12:04 AM, David Hachadorian wrote:
> After exchanging emails with N4ZR, who started this thread, we think 
> this is the easiest procedure:
> 
> Tune the rig to 10.000 MHz in CW mode.  Listen to the tone of the WWV 
> carrier, which should be close to your CW PITCH setting.
> Switch back and forth between reverse cw and normal cw, adjusting REF 
> CAL until the tones are equal in pitch on normal and reverse.
> 
> This procedure should get you calibrated well within 1 Hz, much better 
> than required for any amateur radio application that I can think of.
> 
> Dave Hachadorian, K6LL
> Yuma, AZ
> 
> 
> On 12/18/2021 2:39 PM, Bob McGraw wrote:
>> The method I use seems to work great and be easy enough to do. No zero 
>> beating required and no external measurements required.
>>
>> Put the radio in CW mode, tune to a WWV frequency and press and 
>> release SPOT.  The radio will automatically zero to the carrier with a 
>> tone that matches your preferred CW note.  Then via the CONFIG MENU go 
>> to REF CAL and adjust up or down with the VFO A knob,  the number of 
>> Hz error the previous SPOT routine disclosed.   A 10 Hz change on the 
>> REF CAL will equate to about 2 Hz at 10 MHz.    I find that checking 
>> several different WWV frequencies is even better using this method. To 
>> make sure it is optimum, tune to 5 or 10 Hz above and below each of 
>> the WWV frequencies.  Press SPOT from both above and below and see how 
>> it resolves.   Usually I can get within 2 Hz or better on all of 
>> them.  You may need to do this several times.  Be sure the radio has 
>> been on for at least 1/2 hour to allow things to stabilize.
>>
>> 73
>>
>> Bob, K4TAX
>>
>>
>>> Message: 4
>>> Date: Thu, 16 Dec 2021 18:46:59 -0500
>>> From: Don Wilhelm<don at w3fpr.com>
>>> To: Pete Smith N4ZR<pete.n4zr at gmail.com>, Elecraft List
>>> <elecraft at mailman.qth.net>
>>> Subject: Re: [Elecraft] K3 Frequency Calibration
>>> Message-ID:<81d4d693-6cd1-f11b-30b7-d4523ce74bb8 at w3fpr.com>
>>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>>
>>> Pete,
>>>
>>> When using WWV to set the K3 reference, make certain you are listening
>>> to the carrier.? WWV is an AM signal that is modulated by a 500 or 600
>>> Hz tone on alternate minutes (440 Hz 2 minutes after the hour).? That
>>> produces tones that are both above and below the carrier.
>>> So be certain you are hearing the carrier and not one of the modulating
>>> tones.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>> On 12/16/2021 4:34 PM, Pete Smith N4ZR wrote:
>>>> I've been wondering for some time if my 10-year-old K3's frequency
>>>> calibration was off, because it seemed like most spots of me were well
>>>> off when I clicked on them, usually in one direction.? Not having a
>>>> frequency counter, I went to the alternative method outlined in page
>>>> 49 of the manual.? I thought I did it all "by the book", but found
>>>> that when I was done 15-MHz WWV's carrier frequency (determined by
>>>> zero-beating the carrier) was almost 400 Hz low. Since I wasn't
>>>> looking for FMT-level accuracy, I went back to WWV and adjusted the
>>>> REF CAL setting by ear until 15.000 on my RX dial was as close to
>>>> zero-beat with WWV as I could tell. We'll see how it worked out, but I
>>>> wonder if I simply have some fundamental misunderstanding of what's
>>>> involved.? Wouldn't be the first time...
>>>>
>>>
>>> ------------------------------
>>>
>>> Message: 5
>>> Date: Thu, 16 Dec 2021 17:01:50 -0700
>>> From: David Hachadorian<k6ll.dave at gmail.com>
>>> To: Pete Smith N4ZR<pete.n4zr at gmail.com>, Reflector Elecraft
>>> <elecraft at mailman.qth.net>
>>> Subject: Re: [Elecraft] K3 Frequency Calibration
>>> Message-ID:<6453871f-7e7d-fa93-8a79-7b1efd5e4296 at gmail.com>
>>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>>
>>> You had it fixed, but then you broke it again. After doing the
>>> alternative method on page 49, when you tune in to 10.0000 MHz in CW
>>> mode, you should hear a CW note at the same frequency as your PITCH
>>> selection.? I presume that is 400 Hz.
>>>
>>> I got an extremely good score on last year's Frequency Measuring Test
>>> using only that alternative calibration method.
>>>
>>> 73
>>>
>>> Dave Hachadorian, K6LL
>>> Yuma, AZ
>>>
>>>
>>>
>>> ------------------------------
>>>
>>> Message: 6
>>> Date: Thu, 16 Dec 2021 23:04:36 -0800
>>> From: Ray<wa6vab at gmail.com>
>>> To: Wes<wes_n7ws at triconet.org>, "elecraft at mailman.qth.net"
>>> <elecraft at mailman.qth.net>
>>> Subject: Re: [Elecraft] K3 Frequency Calibration
>>> Message-ID:<61bc3686.1c69fb81.f8fd0.8d81 at mx.google.com>
>>> Content-Type: text/plain; charset="utf-8"
>>>
>>> Gents
>>> Go to a WWV signal, (5.000000)  on a Good Strong Frequency.
>>> Place the Mode To Upper SSB, Listen to the Beat note Tone Freq,
>>> Now Move the Mode to Lower SSB. Adjust the  Ref. Cal. Osc. until the 
>>> Beat Note is the Exact Same Freq
>>> On Lower SSB and Upper SSB.   Done
>>> Ray WA6VAB  K3