[Elecraft] KSB2 Mod

[Ron D'Eau Claire]

There's a reason the crystals are sold as a match set of 14. Replacing
only part of them is NOT a good option from what I understand.

It's a matter of luck about the crystals you already have installed.
Some ops might get away with changing only some of them and end up with
good performance, but the reason they are shipped as a set is so you
won't be 'guessing' about whether they are all matched or not. If you
are happy with "guessing" at the match, the crystals you have already
will be as good as any. 

The reason for changing them in the first place has to do with getting
adequate bandwidth for good SSB voice or to cure a problem with too much
attenuation at narrow CW bandwidths. You won't notice any improvement
running PSK 31. A LOT (perhaps most) K2's were shipped with crystal sets
that were just fine. 

In my rig changing the crystals to fix a problem with adequate bandwidth
for voice transmission did affect the behavior of the CW filters. The
new crystals do produce a larger shape factor - that is they have
steeper "sides". I used to run my narrowest CW filter at 200 Hz. I don't
like the sound of it now at 200 Hz. The steep sides produce a sound that
I don't like. My filter at 400 Hz bandwidth now sounds more my old set
of crystals were at 200 Hz, so using a slightly wider bandwidth fixed
that for me. I never noted any significant attenuation on the narrow CW
settings, either before or after changing the crystals. The filter works
great as far as I'm concerned and changing the crystals gained me the
bandwidth needed for decent SSB voice quality. 

Ron AC7AC
K2 # 1289