[Antennas] RE: Antennas Digest, Vol 13, Issue 10

[bill croghan]

Tom Said,
> (Remember to tune and load your amp into a dummy load
> *before* trying to match the output to a tuner. Less QRM
> and its better for both amp and tuner, regardless of make
> and model.)
Bill Says;
	Better yet, never tune the tuner with the amp on.  Tune the tuner
with the exciter, that is the radio transmitter used to drive the amp.  Do
that at the lowest power that will give you accurate readings.  Then when
you turn on the amp, it will be going into a proper load.  If the VSWR
changes with higher power, you have other problems, i.e. elements heating,
Spurious Emissions, etc.   VSWR is never a function of power.  A 50 ohm load
at 1 watt is still a 50 ohm load at 1000, UNLESS something in the load
changes with the added heat or whatever from the amplifier.  Tuning an
antenna tuner with the amp on is a bad breach of etiquette on the ham bands.
Tune the amp, yes, but into an already tuned tuner/load.  That keeps the
interference to a minimum and for a minimum time.

Bill Croghan WB0KSW
Chief Engineer,
Lotus Broadcasting, Las Vegas
KOMP/KENO/KXPT/KBAD
Las Vegas, NV