[Elecraft] K3 6m pre-amp

[Dave G4AON]

I've just done an A/B comparison between my K3 and my Kenwood TS-480SAT. 
I had the pre-amp switched on in both transceivers.  On the 480 I was 
able to comfortably hear a signal from my signal generator some 10 dB 
lower in level on the 480 than I could on the K3, which is quite a 
difference.

I think the often quoted MDS (minimum discernible signal) makes the 
specification appear "better" than it really is and is not realistic. 
MDS is a measure of the signal that increases the output of the receiver 
by 3 dB when the signal generators output is turned on. You couldn't 
copy by ear a signal of that level except for the slowest of Morse 
keying and then it would be very hard going. The "old fashioned" signal 
level that gives a signal to noise ratio of 10 dB is more meaningful, as 
a 10 dB above the noise signal is a comfortable listening level that we 
can all equate to.

I had done earlier A/B comparisons between the K3 and 480 where I didn't 
think there was a difference, I must have mistakenly not use the 480 
pre-amp...

73 Dave, G4AON
K3/100 #80