K3 s-meter calibration parameters and flickering S1...

Posted by VK7JB on May 30, 2011; 12:49pm
URL: http://elecraft.85.s1.nabble.com/K3-s-meter-calibration-parameters-and-flickering-S1-tp6418969.html

Hello again,

Update to my last post:  I turned everything off, went and had a cup of coffee, came back and tried the RF gain calibration routine again with K3 Utility - worked just fine this time.  So, not sure why those errors.  I had turned everything off and re-booted the K3,  restarted the utility etc in previous attempts, with no effect.  Must've been the cup of coffee :)

So now on to another question:

After the RF calibration, I re-did the S-meter calibration using the XG3, with the K3 in ABS mode, PRE OFF.
SMTR OF = 21,  SMTR SC = 14.
With these parameters, the scale is very linear and pretty much spot on:  S9 @ -73dBm, S2-3 @ -107dBm,  S9+40 @ -33dBm

BUT, when I disconnect the XG3, so nothing is connected to ANT1, the S1 bar flickers on and off.

I can't  stop this flickering S1 without readjusting the parameters and throwing out the rest of the calibration.

The S1 does turn off if I narrow the bandwidth to less than 1.5khz.  I've been doing the calibration in CW mode but with bw set at 2.8khz.

Is this flickering S1 with no antenna connected "normal"/expected?  Intuitively, I feel that no input should give no bars, but perhaps that simplistic.

73,

John
VK7JB