[Elecraft] Re: K2 Instability on Transmit

Mon Feb 4 09:05:12 2002

I also have had a strange 'drifting' behavior similar to that to which John =

refers, although I am pretty sure I've only had it happen in split mode.=20
Usually when I hit A=3DB it goes away.  But for a bit, when I transmit I =
can=20
watch the display slowly move upwards (in the second spot to the right of=20
the decimal), and the op I'm working indicates there has been a drift.=20
Once, during a round-table on cw, my signal just took off up band, and I=20
didn't realize it until I heard the guys I was operating talking about the=20
disappearance of my signal up band.  That was, however, with the 1.06=20
firmware, and I haven't had anything quite that drastic with the new=20
firmware.

So, whether this is the same as your problem, John, which seems to be rit=20
related, or an altogether different problem, I don't know.  But they sure=20
sound related.  It's almost like some offset is being recalculated in=20
dynamically iterative manner.  It doesn't happen often and I don't ever=20
recall its happening to the receive frequency, just the transmit.

best wishes,

dave belsley, w1euy

--On Monday, February 4, 2002 7:44 AM -0600 Tom Hammond N=D8SS=20
<[email protected]> wrote:

> John:
>
>> K3 #139 performed **almost** perfectly during the FOC Marathon this
>> weekend.
>
> You have a "K3"... damn! I thought ALL Of the FT's would get it, not just
> a 'chosen few'...!!! <G>
>
>> The rig was interfaced to TR Log via the KIO2 and the combination
>> was amazing. The power of TR Log (freeware version) surprised me.
>
> Had I known you were gonna use TRLog, I'd have sent you a Full-Blown
> (e.g. current) release to try out!
>
>> Now for the problem... Twice during the contest (which I operated about
>> 12 hours) the frequency display on the K2 would begin to dither, in
>> random fashion, while transmitting CW. The dithering was fortunately
>> confined to the right of the frequency readout decimal point as I
>> recall. Also, the sound of the sidetone became choppy when this happened
>> and several stations commented on the drifting. In one case, simply
>> disengaging RIT corrected the problem; in the other, powering on/off
>> twice was necessary.  The K2 ran cool the whole time so I don't think
>> heat is an issue. With contest style operation, T/R change-over cycles
>> are short/rapid/frequent which might be challenging to internal timing.
>
> Hmmm... I operated 20+ hours in the CW SS and never experienced any
> problems... any chance it might have been RF-inflicted?
>
>> I also notice that occasionally, when RIT is engaged, the transmit
>> frequency does not always display when transmitting on this K2 (the
>> display stays on the RIT freq). This has happened often since the rig
>> was put into service July of 99, but I don't know if the transmit freq
>> actually "jumps" or if it's just the display. No one has ever made note
>> of it on the air.
>
> This is NORMAL (e.g. firmware-related)... I think all of us who run RIT
> with ANY logging program find the same thing occuring.
>
>> Although this problem resulted in only seconds of inconvenience over
>> hours of otherwise flawless contest operation, I am concerned that it
>> might get worse and hopeful there is a known cause and solution.Your
>> advice would be appreciated. Has anyone else reported such a problem?
>
> Tom
>
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----------------------------
David A. Belsley
Professor of Economics