[Elecraft] contest reflections on K2 - addendum

[Jack Smith]

Doug:

You might find my measurements useful in understanding your K2's audio 
output with changes in RF input levels. 
http://www.cliftonlaboratories.com/receiver_agc_curves.htm

Some receivers have an AGC curve that holds the audio output constant 
for 80 dB or more variation in input level, such as the Racal RA6790/GM. 
The K2's AGC does not have this flat-top characteristic. Rather, the 
audio output increases with RF input, but obviously not at a 1 dB : 1 dB 
rate.

Depending on whether you have the pre-amp on or off, the K2's audio 
changes as much as 40 dB over an input range from -120 dBm to -20 dBm. 
Under those operating conditions, the AGC works at about a 2.5 dB : 1 
dB, RF to audio change.

As you say, some folks like the AGC to hold the audio constant and 
others a K2-type action.


Jack K8ZOA
www.cliftonlaboratories.com


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