[Elecraft] K2 version A and B

[Don Wilhelm]

Barry,

All K2s above SN 3000 are revision B - and that is what is being shipped 
today.

The original Field Test and Rev A K2s began to have many mods added to 
them, so finally the boards were laid out again to incorporate all those 
mods onto the new boards - the result was Rev B.  I believe that 
happened in 2003.

A fully upgraded early K2 will perform just like a brand new one.  One 
witness to that fact is my SN 00020 which was a Field Test model.

There are a substantial number of mod kits for the K2, and they are 
listed on the K2 A to B upgrade instruction sheets.
The one thing that is not covered in those instructions is the 
installation of the upgraded IF crystals (changed at SN 2560) and the 
KSB2 mods such as the PSK mod and the widening of the KSB2 filter to 
2.4kHz instead of the original 2.1kHz.

Also not covered is upgrading the KPA100 - the KPA100UPKT will bring any 
KPA100 up to the latest level.  The KPA100 does not carry a serial 
number, so the latest level must be determined by inspection.  If 
toroids L16 and at RFC4 have blue cores, it is the latest.  The older 
ones have red cores at L15 and L16.  There have also been upgrades in 
the KPA100 shield.  The latest has a 1/4 inch wide slot above the SO239 
jack and has spring clips that ground the shield to the sides of the 
base K2.  For other than the Field Test KPA100s, the board has not been 
changed.

73,
Don W3FPR

On 6/25/2020 2:51 PM, barry halterman wrote:
> Could someone tell me main differences between the version A and B for the
> K2?
> Is the version B being shipped now if ordered?