Tom, like I told you before, I do not have the ALC connected up on my
ALS-600. I called the Ameritron tech and asked him about this and he told me
that it was not necessary if I was driving the ALS-600 with a rig like the
TS-590. In addition, he told me that I could drive it with up to 100 watts
with no problems. Finally, the most significant issue I have with my ALS-600
is the reflected power level. That is, even with the automatic antenna
tuner, you will still have an issue with reflected power, especially when
using coax. If your reflected power is as much as 50 watts or more, it will
cause the automatic protection shut down circuit in your ALS-600 to cut back
its power to reduce the reflected power to below 50 watts. If you use an
antenna system that results in reflected power of less than 50 watts, you
should be just fine. This is why I plan to change the feedline to my loop
antenna at my lake house from 52 ohm coax to open wire feedline. It should
substantially reduce my reflected power as seen by my ALS-600, thus,
allowing me to get more out of my amp, plus, with the open wire feedline,
the reflected power will be radiated, improving the overall performance of
my antenna system, rather than heating up my coax and causing other
problems.

In other words, don't be so concerned about the ALC and be more concerned
about your antenna systems, with the objective of keeping the reflected
power below 50 watts. Also, if you are getting good performance with 60
watts drive out of your transceiver and a little over 500 watts out of your
ALS-600, be delighted with that and just leave it alone! You will be running
your gear in a nice, comfortable, safe zone!! <big smile>

Ron, K8HSY