[Elecraft] K3 Calibration

[Fred Jensen]

That's it!  Thanks.  Really works good.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org

On 12/5/2010 8:26 PM, Gary wrote:
> Not sure but I think you're referring to the thread a couple days ago
> entitled "determining zero-beat" started by Pete, N4ZR on December 3rd. Guy,
> K2AV supplied the following instructions;
>
> "-----Original Message-----
> From: Guy Olinger K2AV
> Sent: Friday, December 03, 2010 5:38 AM
> Subject: Re: [Elecraft] Determining zero-beat
>
> Set mode to CW.  Set width to 200 Hz.  Do a HOLD on MON. Set level to
> 20-25. Tap MON to turn off beat.  Tune to 10.000.000.  Tap SPOT.
> Should hear a beat, albeit a slow one.  Advance or retard AF gain to
> get the obvious beat. In CONFIG: go to REF CAL.  This will have turned
> off SPOT.  Tap it again. Adjust VFO A to get slowest beat.
>
> With some patience and careful listening this is usually clearly a
> specific setting, in my case 49.379.737.  You will find that the beat
> frequency wavers around due to changing propagation path length so you
> have to listen for a while.  Having accounted for the variation in
> propagation it is quite clear in my case, albeit subtle, that 738 is
> too high, and 736 is too low.  It is also more clearly heard at some
> times of day on a given frequency than others.  There are also times
> where there is a fast QSB on the signal that can be confusing and you
> may just have to wait until the signal steadies.  When you have it
> spot on, there will be periods of several seconds or more where the
> beat does not vary, something which does not happen nearly as much up
> or down one Hz on the REF CAL frequency.
>
> After this adjustment it is clear that my K3 is within +/- 0.5 Hz at
> 10.000000 MHz with no drift, probably within +/- 0.2 Hz though I won't
> claim that.  I have the KTCXO3-1 option in mine.  It may be that a K3
> without it may be a bit more cranky, I would imagine so, but I'm not
> pulling it out to see  :>)
>
> 0.5 Hz at 10 will be less than 2.5 Hz at 50, though I don't know the
> formula.  It's not a straight multiply because of the conversion
> scheme.  With this adjustment in the menu, the chief contribution of
> the KTCXO3-1 is no drift, not an absolute accuracy.
>
> My K3 is way more accurate than they spec, and accurate enough to show
> up the propagational variations in the WWV frequencies. I would think
> that if you have left it on for a while, and calibrate it before an
> "exercise", you can count on it for spot on.
> 73, Guy."
>
> And Bill, W5WVO offered the following supplemental help;
> -----Original Message-----
> From: Bill VanAlstyne W5WVO
> Sent: Friday, December 03, 2010 5:49 AM
> Subject: Re: [Elecraft] Determining zero-beat
>
> Just one caveat on this procedure (thanks Guy!) -- make sure you have CWT
> turned OFF; otherwise, SPOT will not do what you want it to. (It will
> attempt to retune the VFO.)
> Bill W5WVO
>
> Gary
> N6LRV
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Fred Jensen
> Sent: Sunday, December 05, 2010 7:34 PM
> To: Elecraft Reflector
> Subject: Re: [Elecraft] K3 Calibration
>
> OK Folks,
>
> Last year, during a snowstorm when the static was unbearable on the
> radio, I decided to "tidy up the computer."  The result was I formed a
> "New Rule," don't save stuff you print.  I pasted this down into my
> engineering notebook, but I no longer have it on this computer.
> Sometimes, "tidy" sucks.
>
> The best thing would be for whomever posted this wisdom step up and
> repost it, no doubt he has not done the "tidy job" on his machine.
>
>
>
>
>
>
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