[Elecraft] K2 Case-distortion-induced Freq INstability

[Tom Hammond NØSS]

Folks:

This note recently received from Joe Levy (unfortunately, callsign unknown).

Joe had come up with a cheap and simple fix to a complaint that several 
users have written about... that being that the K2 shifts frequency just a 
bit when the bottom of the case is squeezed, or when the bail (flip-down 
stand) is lowered. Here's Joe's posting on this subject.

Hello Tom

As an owner of a recently built K2 (2315) and a devoted reader of the 
reflector for the last 2(?) years I came across a lot of "complaints", some 
that were eventually fixed (either by Elecraft or by some users ingenuity).

One of the minor complaints was that the bottom plate of the k2 is too 
compliant and when the folding legs are opened the frequency moved, and the 
same frequency shift happened when the bottom of the case was squeezed 
during handling mor moving of the case.

The solution to this problem is extremely simple as you'll see in the 
attached photo.
(I'm omitting Joe's photo because ATTACHments can't be posted to the 
reflector. - Tom)

Just added 2-3 plastic spacers of the exact height (secured with hot glue) 
so the bottom panel does not change it's spacing from the printed board 
when the case is handled. The length of the spacers has been 'adjusted' a 
bit, so they just touch the insied of the bottom cover when it is 
installed, thus preventing it from being distorted during handling.  These 
spacers are situated in the so the movement near L33 and L31 is minimized. 
Their location is also determined by available 'empty' PC board space, so 
they don't interfere with with already-installed components.

Joe Levy, in Israel
_______________

Tom's few comments:

I do have a picture of the bottom of Joe's K2, showing where he situated 
the added plastic spacers. If you cannot visualize what he's describing, 
drop me a note and I'll e-mail the picture to you, but I doubt it should be 
required... the explanation seems pretty self-evident.

Joe's solution should go a LONG way to curing any pesky problems you might 
have with your K2 shifting frequency as a result of minor movement in the 
bottom (front) cover.

Thanks for such an easy fix, Joe.

73,

Tom Hammond   N0SS