[Elecraft] K3 and Expert Amp

[Jim Brown]

On 9/21/2012 9:37 AM, Gary Slagel wrote:
>   I'm looking at the SPE Expert Amp 1K-FA.  The SPE amps both recommend using an ALC connection to automatically control the radio's output power thus preventing amplifier overdrive.

It is NEVER a good idea to use ALC to set drive level to a power amp. 
Doing so is a recipe for distortion, key clicks, and splatter. ALWAYS 
control the amplifier output power by setting the POWER OUTPUT of the 
transceiver so that the transceiver produces just enough output power to 
get the desired power from the amplifier.

IF you want to use ALC, use it ONLY to protect the power amp from 
failures in the antenna system.  Think of it as "belt and suspenders."  
FWIW, I've NEVER used ALC between any rig and amp that I've owned or 
operated.

Modern amplifiers do NOT need ALC -- indeed, "modern" includes my 
vintage Ten Tec Titan power amps that were designed in the late '70s and 
built well into the '80s. The manual notes that although an ALC output 
is provided for compatibility with older rigs, it should not be used 
except as I've described.

73, Jim K9YC