I noticed something fairly interesting today, under certain operating conditions my FT857D will exceed the power limit, the highest I saw it go was around 150W! This happened when the power was set to 8W or below on 20m 17m 15m 10m etc (but not VHF/UHF). Strangely, 80m and 40m works as expected. I was working PSK31 and adjusting the Digi Gain when I noticed this first. With the output set to 8W or lower increasing the Digi Gain kept increasing the output power. At first I wrote this off to my tuner giving me a wrong value but then I noticed the current draw from my power supply.
This was not only when doing digital, I saw the same behavior on AM. When set to 5W the output could be as high as 40W. I'm really glad I saw this in the shack and didn't take this radio for QRP operation as I was planning. Has anyone seen something like this before?
These results were confirmed when operating into a dummy load. It seems to be an ALC problem. On 40m the ALC works as expected, on 20m the ALC level is noticeably lower and the power a bit over what I set it. On 10m the ALC doesn't seem to kick in at all and the power output is 130W+.