K3 MDS calculations using the Elecraft XG2

[Fred Atchley]

I set up the K3 Rx sensitivity test (using 1 microvolt signal) according to
XG2 manual.

It seems to work in general except that the resulting MDS calculations seem
too low:

123 dBm on 80 meters,

132 dBm on 40 meters, and

130 dBm on 20 meters.

 

I am using the front headphone jack on the K3, with the CONFIG:SPKR = 1. AGC
is off.

Preamp is own, RF & AF gains are at maximum, and the CW passband is set to
500 Hz.

The AC measurements were made using a Craftsman autoranging multimeter.

 

Example: on 40 meters the reading was 0.310 V with XG2 on and 0.018 V with
XG2 off.

(0.310/0.018) = 17.2.

Log 17.2 x 20 = -24.7 dBm.

MDS = -107 dBm -24.7 dBm = 131.7 dBm.

 

I was expecting a better value (maybe -137 dBm?)

 

Could it be a problem with the DMM? If so, is there a recommended DMM?

Thanks in advance for your help.

 

73, Fred AE6IC

 

 

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[KK7P]

> Could it be a problem with the DMM? If so, is there a recommended DMM?
>  

If using the K3, use the internal RMS audio meter (tap DISP then rotate
until you see AFV).

73,

Lyle KK7P

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