Roy Lewallen wrote in
:

....
But my 25 year old Icom 730 delivers a full 100 watts to the output
regardless of the SWR up until it starts shutting down at around 3:1.
For example, with a 2.38:1 SWR, the "forward power" is 120 watts and
the
"reverse power" is 20 watts. Aren't modern rigs able to do this, or
have
they gone to the simpler system like I use in my homebrew rig?

Roy,

Modern rigs often employ a range of protective devices that influence the
power delivered to the load.

Many of the modern Icom HF radios control:
- 'maximum output power' using either the forward output of a directional
coupler or a non directional sample of output;
- VSWR protection to limit maximum reflected power indicated by the
directional coupler, typically to a value that is equivalent to the
reflected power at rated output and specified maximum VSWR (eg 11W for a
transmitter rated at 100W and max VSWR=2:1);
- maximum collector current.

The actual power delivered to a severely mismatched load is affected by
all of these. It is likely for such a radio that with a 5 ohm load, the
radio will level 'reflected' power to 11W, 'forward' power would be
16.5W, output power would be 5.5W.

Depending on the way in which maximum output power is detected /
controlled, it is indeed possible to get more than rated output power, so
mismatch doesn't necessarily result in lower radiated power (despite
popular opinion).

Owen