[Elecraft] K3S QST Article

[Wayne Burdick]

> Based upon your experience and understanding of the issue, would an original K3 (not K3s) with the new synths have better TX IMD?  In other words, is the poor TX IMD of the K3s a function of some part of the rig not associated with the new synths?
> 
> Dave   AB7E


Hi all,

This has nothing to do with the new synthesizer.

Normally, the K3S (or K3) has worst-case TX 3rd-order IMD in the vicinity of -30 dBc (ARRL method) at rated power (10 W/100 W +/- 1 dB on most bands; see specs for exceptions). Nearly all other 12-V-capable transceivers are in this same range, because they all use approximately the same circuitry and PA devices. 

We have made changes in K3S production that improve average IMD performance at both low and high power levels by as much as 3 dB. We will make these changes free of charge on any K3S returned to the factory for this purpose, whether or not it is still in the warranty period. The only charge would be for return shipping.

The changes were phased in at the following serial numbers:

  KPA3A (100 W PA option):    Factory assembled, #10852    Kit, #10864
  LPA (10 W module):          Factory assembled, #10920    Kit, #10939

Please email k3support at elecraft.com if you have any further questions.

73,
Wayne
N6KR