Re: [KX3] Need Advice - Xmt & Rcv frequencies differ but RIT turned off

Posted by tcollen on Aug 12, 2014; 7:14pm
URL: http://elecraft.85.s1.nabble.com/KX3-Need-Advice-Xmt-Rcv-frequencies-differ-but-RIT-turned-off-tp7592042p7592051.html

Hi Jerry,

My TS-590 exhibits almost a similar situation, without the SO-3 high-stability oscillator installed. The specs say the 590's frequency stability is within +- 5ppm, and I've found the higher in frequency I go, the further up I need to tune to zero-beat a station. On 20m, I've found I have to consistently tune up a bit to center.

Doing the math, it looks like your KX3 is at least consistently off by 25 or 26 ppm:

133 / 5.0 = 26.6 ppm
190 / 7.335 = 25.9 ppm
250 / 10.0 = 25 ppm
384 / 15.0 = 25.6 ppm

25-26 ppm definitely adds up, and it seems to me the unit is mis-calibrated, but I don't know what the KX3's tolerance for frequency stability is.  I'm a new KX3 owner myself so I haven't had enough experience with it to figure out if my unit is off by a small bit or not.

Does the behavior change when the unit has been off for a while, vs when it warms up?

Cheers,

 - Tony, N0RUA