> I suggest one should not vary the switches on coil taps or vary the
> roller inductor with power applied!
I certainly wouldn't adjust a roller inductor while transmitting near
the tuner's rated power, but virtually any roller inductor can be
adjusted while transmitting at reasonable power levels without harm
to the inductor. Doing harm to the device driving the tuner is
another issue! Some rigs won't take even brief periods of high SWR.
It definitely isn't a good idea to switch a switched inductor while
transmitting even if you do reduce power. Switch contacts are very
very easy to damage even with a low power arc.
One excellent tip mentioned before was to always use the
maximum possible capacitance that allows a match in a
conventional T-network type tuner.
73, Tom W8JI