[Elecraft] K2 Sidetone

[Don Wilhelm]

Frank,

That mod is not for all K2s - the K2 design was changed to produce a 
more sine-wave sidetone.  Look closely at the information below.

If your K2 serial number is lower than 3000 - *and* you have not 
installed the K2ATOB mod kit, then that can be a worthwhile change.
Be aware that this published mod is quite old, and will cause problems 
if you attempt to apply it to a K2 above SN3000 or one which has been 
upgraded with the A to B mods.

The sidetone changes made with the A to B kit and K2s above SN 3000 are 
not exactly the same as this mod, but do essentially the same thing, but 
with slightly different component values.

If your K2 is below SN3000 and has not yet had the A to B kit installed 
as well as the other mod kits indicated on the A to B Instruction 
sheets, then I recommend you do those upgrades instead of just adding 
the sidetone mod.  The temperature stability and electrical stability of 
your older K2 will be improved substantially.

If the serial number is below 2560, you will also benefit by changing 
the IF crystals on both the base K2 and the KSB2 option for a smoother 
filter response.  Look at the markings on the crystals - the new 
crystals have a "-S" suffix marked on them.  If it is anything else, you 
have the older crystals.  The new crystals were shipped with kits 
beginning at SN 2560.

73,
Don W3FPR

On 7/3/2016 4:43 PM, kg9hfrank at gmail.com wrote:
> So I have had some quality time with my K2 this weekend.
> I am thinking of doing this modification to my sidetone, has anyone tried it?
>
> http://qrpzone.com/elecraft-k2-side-tone-mod/
>
> Seems pretty easy to do and I have always thought it was “my ears”.
>
> Comments?
>
>