[Elecraft] K3S Preamp 2 Six Meter Noise Figure

[Edward R Cole]

I did some checking on this.

QST article shows K3S MDS using preamp 2 as -145 dBm for 6m which is 
pretty good.
Calculating MDS for a NF of 2 dB provides -146.5 dBm using a bandpass 
of 500-Hz (which is what Elecraft cites for MDS).

The NF for 14 MHz is 8 dB (which is nominal on most new HF 
receivers).  MDS = -139 dBm measured by ARRL for preamp 1

I use the PR6-10 on my K3 which the same as preamp 2 in the K3S (I believe).
My external ARR GasFet preamp is cited 0.5 dB NF which corresponds to 
-155.1 dBm (with PR6-10 off)

-145 dBm is quite respectable MDS on 6m.  -155 dBm is eme level.

73, Ed - KL7UW
   http://www.kl7uw.com
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