On Thu,10/22/2015 3:34 PM, j...@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 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
