[Elecraft] Mic Settings

[Jim Brown]

On Thu,10/22/2015 3:34 PM, john at kk9a.com wrote:
> Today I received unsoiled
> complaints that my audio was clipping at the top.

Your audio was very clean here and you were solid copy except for 
occasional QRM, but the path was not great, so not good enough for me to 
hear clip or splatter. EQ sounds very good for contesting.

Don has given you excellent advice about setting levels. Audio can be 
"clipping at the top" if a power amp is overdriven or not properly 
tuned. Some general things I've learned over the years, mostly from 
K6XX. One reason he made sure I learned it is that we're neighbors, and 
could make life miserable for each other if we goof. :)

1) NEVER depend on ALC between an amp and the rig to set drive level -- 
it's a recipe for clipping and splatter.  Always reduce output from the 
transceiver using the power setting control.

2) ALL power amps need to be matched to their load. A poorly matched amp 
will splatter or click.  Tube amps can be matched to reasonably 
well-matched antennas by the output networks within the amps.

3) Be sure you understand the difference between "auto-tune" which 
correctly finds the right match, and "auto-recall" which simply recalls 
the last settings you used on that band, and are only as good as that 
last tuning you did. Study the manual to figure out which kind of amp 
you have. :) I don't know the ACOM 2000. As I understand it, the Alpha 
87A is in the auto-recall category.

4) Solid state "no-tune" amps NEED an antenna tuner to match them to 
antennas that are not 1:1. Without that tuner, their distortion will 
increase and they will splatter or click.

73, Jim K9YC