[Elecraft] K2 VFO knob

[Bill Coleman]

On 1/26/03 12:57 AM, Daniel L Brinneman at daniel-k2@juno.com wrote:

>I don't have any problems tuning or keeping my finger on the wheel in a
>constant circle of spinning.  Worn off the front a bit. No objections to
>a new knob, just that I paid for the K2 with holes already in my pockets,
>and satisfied with what I own.

In speaking about the K2 knob -- I really don't think the problem centers 
in the knob itself, but in the encoder.

Elecraft used an encoder with 100 steps / revolution. This animal isn't 
cheap -- in fact, it is one of the most expensive parts in the K2. 

However, 100 steps isn't that many for a tuning knob. At 10 Hz per step, 
a full revolution is only 1 kHz. That's really slow tuning. Switch to 100 
Hz per step, and you get 10 kHz / rev -- a reasonable tuning rate, but 
the steps are big.

Compare this with other synthesized tranceivers. My venerable TS-430S 
uses a 960 step encoder. At 10 Hz per step, that's 9.6 kHz / rev -- a 
good tuning rate, with small steps.

You see the issue. Since the K2 encoder has 10x fewer steps, you either 
don't get far up the band with every turn, or you don't have the real 
fine control. (In SSB contests, I always keep the K2 in the 100 Hz rate 
-- otherwise it takes forever to tune across the band)

If the encoder had 400 steps / rev, you wouldn't need to crank the knob 
as much, and the lack of a dimple wouldn't be an issue.

But, it would cost more.




Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901