[Elecraft] Re: Microphone connections for K3 #1540

[Jim Brown]

On Tue, 2 Sep 2008 14:03:56 +0000, LANCE COLLISTER wrote:

>This is GREAT NEWS for those of us who use noisy amplifiers! 

There are other solutions. First, don't turn the mic gain up so 
high, or use so much processing(compression). 10 dB of processing is 
enough -- more tends to sound bad. Second, roll off the low end 
octaves that contribute nothing to communications. In the K3, the 50 
Hz and 100 Hz filters should be all the way down. Third, use sound 
absorbing materials in your shack to reduce the "liveness" that 
amplifies the noise (and makes it difficult to copy on your 
speaker). Some absorption on the surfaces around the noisy fans 
should have a high priority. Fourth, a directional mic will reject a 
lot of noise. The Appendix on Audio For Ham Radio that is part of my 
RFI Tutorial lists a bunch of good directional mics. 

http://audiosystemsgroup.com/RFI-Ham.pdf

Downward expansion can be a problem solver if done well, but don't 
hold out a lot of hope for downward expansion in DSP to solve your 
problem. It is notoriously difficult to get DSP to sound good with 
dynamics processing.  

73,

Jim Brown K9YC