[Elecraft] ALC control of W6PQL amp from my K3

[Jim Brown]

On 3/10/2019 11:34 AM, John Simmons wrote:
> Once I got my LP100, I began to see the same behavior with my K3. This 
> type of output anomaly is a huge reason to use ALC. 

I've had an LP100 in line for several years, always set to read peak 
power, and the most overshoot I've seen from either of my two K3s is 
less than 1 dB. The K3s are driving a pair of 87As, and I have NEVER 
used ALC between rig and amp.

The earliest advice I've seen about this was in the user manual for the 
Ten Tec Titan 425, designed around 1979, and using a pair of the same 
3CX8007 triodes used in the 87A. The manual said that ALC output was 
provided only for historical reasons, and advised against using it to 
control output power.

When you look ONLY at output power, you miss the mess that ALC causes. 
To see it, you must look at (or listen to) the transmitted frequency 
spectrum. A P3 on a second radio, or an SDR receiver will clearly reveal 
the splatter and clicks.

73, Jim K9YC