[R-390] Noise Figure Tester

[DJED1 at aol.com]

I was packing up gear for the local flea market, and thought this tester 
might be of interest to one of the R-390 community.   It's a Kay Electric 
Mega-Node which measures receiver noise figure over the range of 5 to 220 MHz.   It 
seems to work OK- I fired it up and measured my R-390A by using the panel meter 
to measure a 3 dB increase in noise as I adjusted the NF tester with a 50 ohm 
impedance.   The radio measured 9 dB noise figure, which seems about right.   
I didn't try one interesting feature, which is that the tester also measures 
at 100 ohms balanced, and 150, 300 and 600 ohms balanced and half of that 
unbalanced.   The range of NF is 0 to 17 dB.   So if you want a different way to 
optimize the sensitivity of the radio, this is it.   Note that the measurement 
is independent of bandwidth.   You can convert from NF to microvolts if you 
assume a bandwidth.
No manual but they are available on the web.
$50 plus shipping from 11767.   e-mail me if your interested.
Ed Newman   WB2LHI