[Elecraft] K2 Tuning VERY STRANGE...

[Ron D' Eau Claire]

Help!

Recently I FINALLY got around to installing the Rev. 2 firmware in my K2
(S/N 1289).

Right away I noticed that the tuning acted very odd. It seemed to take
FOREVER to tune across the band. The faster I twirled the knob, the slower
it seemed to tune!

Finally, today, I did some tests, and my perceptions were right. When I turn
the tuning knob faster, the K2 changes frequency more slowly! Here's how I
tested it:

I set the tuning rate at 10 Hz on 40 meters and tuned my K2 to exactly
7000.00 kHz. I s-l-o-w-l-y tuned upwards, turning the knob exactly 10 turns
at a rate of about 1 turn per second (as indicated by a marker I attached to
the knob so I could count the turns accurately). The frequency now read
7010.06 kHz. Fine.

I set the tuning back to exactly 7000.00 kHz. Now I very quickly turned the
knob ten times exactly. Now it only tuned up to 7.006.41 kHz.

I repeated the experiment a dozen times to be certain that I was turning the
knob exactly 10 turns every time. I was and the results were consistent.
When I turned the knob more quickly, the K2 changed frequency more slowly!
There was some variation. At the faster rate of turning the knob it ended up
between 7004.41 and 7006.92 kHz.

It's as if the uP is not able to read the optical encoder correctly at the
higher tuning rates.

One other important point. I violated a cardinal rule of messing with
equipment; I changed two things at almost the same time. The day before I
put the new firmware in, I also did the mod Wayne requested of those of us
who had been having trouble with the K2 spontaneously QSY'ing in transmit.
It was supposed to keep the Optical Encoder "live" at all times.

So I can't say for certain which mod might be responsible.

Has anyone else noticed this?

Ron AC7AC
K2 # 1289