[Elecraft] maybe I don't understand drift?

Wed Jul 23 21:40:02 2003

Tim, it is uncommon for the dial reading of the rig to change if the signal
frequency is "drifting." However, depending upon how the dial frequency is
developed and displayed, whatever is causing the output frequency to change
can also cause the dial reading to change. I don't recall enough of the K2
logic to say much more.

I would think that 80 Hz drift on 40 meters in an hour's time is a bit much.
But the K2 is not a precision instrument by any means when it comes to dial
calibration and frequency stability.

I suggest that you tune in WWV on 10 MHz with your dial set at 10,001 kHz
LSB and look at the nominal 1000 Hz beatnote on a PSK31 program as a
waterfall track. DigiPan, for example, will measure the beatnote frequency
down to a tenth of a Hz very accurately. If you will note the indicated
frequency on the DigiPan display when you first turn on the radio and make a
chart of frequency vs time for an hour or so, you can get a good idea of
what the rig is doing. The dial indication will not change while making this
test, so any change in beatnote frequency is due to drift within the K2
circuitry.

73/72, George
Amateur Radio W5YR -  the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
"In the 57th year and it just keeps getting better!"
<mailto:[email protected]>

----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Wednesday, July 23, 2003 11:10 AM
Subject: [Elecraft] maybe I don't understand drift?

> Hi George, Tom and all -
>   Yeah Geaorge, the ProII is a spoiler alright! Still one would like to
tinker with the K2 and know that you've done what they can.
>   You know, MY K2 freq readout stays the same....at his end my code buddy
says he thinks its drifting...so I guess it's hard to be sure. Come to think
of it, when people talk about drift I don't know if they actually see their
own frequency display change or not?. Maybe I have this wrong? If I don't
see the readout change does it mean it is not drifting? I better make sure I
understand the definition here!
> 73/Tim
> ============================================================
> From: "George,  W5YR" <[email protected]>
> Date: 2003/07/23 Wed AM 11:39:29 EDT
> To: "Tim" <[email protected]>,
> "Elecraft Reflector" <[email protected]>
> Subject: Re: [Elecraft] acceptable amount of drift?
>
> Tim, the key words here are "acceptable" and "tolerate."
>
> I have never used a rig that drifted that much and would be most unhappy
> with one that did. My 746PRO and PRO2 remain within 2 Hz or less of WWV
> indefinitely while turned on, but both have oven-controlled master
> oscillators. Once you become accustomed to that level of dial calibration
> and frequency stability, it becomes difficult to work with less. But, this
> is subjective, remember.   <:}
>
> My K2 is never closer than about 10 Hz in dial calibration and is much
> further off on some bands. It does, however, seem to be stable enough that
I
> have never noticed the effects of frequency drift.
>
> The second issue to be considered is the rig itself. Although full-dress
> K2/100 kits cost more than my 746PRO, the K2  is of a much simpler design
> which has both pros and cons. One of the pros is reported superior
front-end
> performance. One of the cons is the reported lack of accurate dial
> calibration and associated frequency drift.
>
> Basically, one cannot realistically expect the K2 to display the accuracy
> and stability of the 746PRO or PRO2 regardless of price considerations.
But,
> I cannot toss the PRO2 into a small case and carry a complete station,
> battery operated for several hours,  into the field and enjoy all the
> operational features and performance that is usually required for such a
> venture. With the K2 I can.
>
> So, inevitably, like most things in life and especially with anything
> involving engineering, there are compromises. We learn to accept what we
> cannot realistically change  with and to enjoy what we have.
>
> I suspect that your K2 can be improved, possibly quite a bit, but it will
> never provide the dial accuracy and stability of a rig with an OCXO master
> oscillator.
>
> So, have fun with the K2 and as long as you can hear and work the other
guy,
> what's the problem?   <:}
>
> 73/72, George
> Amateur Radio W5YR -  the Yellow Rose of Texas
> Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
> "In the 57th year and it just keeps getting better!"
> <mailto:[email protected]>
>
>
>
>
>
> ----- Original Message -----
> From: "Tim" <[email protected]>
> To: "Elecraft Reflector" <[email protected]>
> Sent: Wednesday, July 23, 2003 8:01 AM
> Subject: [Elecraft] acceptable amount of drift?
>
>
> > Hi folks -
> > I have no idea what is considered acceptable drift so maybe someone can
> give
> > me some feeback? My K2/100 has every mod every required done to it. Last
> > night after about an hour ragchew with my code buddy he said it appeared
> > that I may have drifted about 80Hz on 40 meters. He's an engineer and
> > usually dead on about these things. If it did drift 80Hz in an hour, is
> that
> > a reasonable amount to tolerate? doesn't really bother me - just want to
> > know if it's mormal. Thanks folks. 73/Tim NZ7C
> >
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>
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