On Jun 23, 8:23 am, Cecil Moore wrote:
Richard Harrison wrote:
Cecil, W5DXP wrote:
"If we monitored only forward current or forward power at the antenna
feedpoint, could we still adjust the tuner?"

Yes because a conjugate match delivers all available power (a maximum)
and a conjugate match also exists at every pair of terminals between the
transmitter and the antenna if the tuner and line are essentially
lossless.

I made an interesting assertion on a related thread over
on QRZ Q&A.

"A CONJUGATE MATCH TO A MISMATCHED LOAD GUARANTEES MAXIMUM
POWER REFLECTED FROM THE LOAD!"

The maximum available power is delivered to a mismatched load
when a conjugate match exists. It follows that is also the
point where the incident power is maximum and the mismatched
load will be reflecting the maximum amount of incident power.

Apparently, one could adjust an antenna tuner for a conjugate
match by monitoring the reflected power at the *output* of the
tuner and adjusting for a maximum. :-)
--
73, Cecil http://www.w5dxp.com

Maxwells law states for efficiency the antenna sysystem must be in
equilibrium.
Equilibrium means that the antenna or antenna system must be a
parallel system because it represents
a full wave length.The transmitter adds a parallel circuit to the
system but it does put stress on the output if the antenna is not in
equilibrium.
It is thus better to keep the stresses away from the transmitter and
contain them in a separate tuner where excess power can slosh
backwards and forwards in the tank circuit, this helps to prevent
expence damage to the finals If you want the antenna system to finish
at the antenna feed point area then you place the tuner at that point,
where it is still part of a antenna system because it allows the
antenna only the power it needs for saturation and where the excess is
circulated in the tuner. If you want the antenna to operate without
the tuner then the antenna will resort to a system where with the
inclusion of a ground system and feed system will act as a heat sink
in the absence of equilibrium at the antenna. When you want the
antenna to radiate the energy it is supplied then it must be in
equilibrium where the distributed loads provide a tank circuit for
efficient radiation without saturation overkill. Remember that what
radiats is a full wave length of wire wether it is all on the antenna
or the antenna spreads the excess to the tuner and the feed system.
You cant stop the radiation you just try to ensure the excess doesn't
create damage when it turns into heat