[Elecraft] on the topic of autotuners

[Stuart Rohre]

One of the issues in the operation of an auto tuner, is that it has to
transmit enough power to be rectified by silicon diodes detecting and
operating in a linear manner.  Also, you have to transmit enough power to
break down the oxides on connectors, RF switches, antenna connections and
anything else in the Antenna circuit before you get enough conduction to
look like the higher transmitter power action on the Antenna circuit.

Thus, there is a lower limit on the detection and effectiveness of the RF
source used to tune the antenna tuner while making the changes in tuner
adjustment easily detected and not too "touchy".  The ideal is to have
enough power used that you have a nice peak to the detected signal, and a
smooth slope up and down around it for the peak detection to work well.

-Stuart
K5KVH