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

[VK7JB]

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

[David Pratt]

John - I would say that if it is just flickering on and off that is
exactly right. It does at least show that the receiver is live and the
residual noise is registering on the S-meter.  Perhaps if you shorted
ANT1 to ground the flickering might reduce.

Personally, if my S-meter did not flicker, I would wonder whether my
receiver is working ;-)

73 de David G4DMP

In a recent message, VK7JB <[hidden email]> writes
>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.



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[KK7P]

Hello John!

In ABS mode this is normal.  It is a consequence of offsets the DSP is
doing to account for the settings of ATT and PRE, along with the method
used to pass S Meter information to the MCU.

73,

Lyle KK7P

> After the RF calibration, I re-did the S-meter calibration using the XG3,
> with the K3 in ABS mode,...
>
> BUT, when I disconnect the XG3, so nothing is connected to ANT1, the S1 bar
> flickers on and off.

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[VK7JB]

Thanks Lyle and David.  Sounds all's configured OK then.   I'll get back to playing with my K3.

73,
John
VK7JB