Reg Edwards wrote:
Jim says,
No, the SWR being measured is on the load side of the meter.
=========================================
Jim,

I have difficulty in telling you this without hurting your feelings.
Or perhaps you are just joking and pulling my leg. Try the other one -
its got bells on.

Meaningless babble.

I will assume you are not joking. You clearly havn't the foggiest idea
of how the so-called SWR meter works. Although you may be in good
company - including not a few professional engineers who have picked
up old-wives' tales from radio amateurs. And have been led astray by
the meter being called something which it isn't.

I assure you I have a very good understanding of how SWR meters in
their various incantations work and how SWR works.

The meter indicates SWR when placed at the ANTENNA end of the line. It
is the antenna which does the terminating. And the meter gives the
correct answers only when the line Zo = 50 ohms.

A SWR meter indicates the SWR of whatever is connected to the load
side of the meter relative to the reference impedance the meter is
designed for.

It matters not if the thing connected to the load side of the meter
is an antenna, an antenna with a transmission line, a transmission
line with a dummy load on the end, or two popsicle sticks and a
bubble gum wrapper.

If you are only interested in the SWR of the antenna and don't, or
can't, correct for the effects of real transmission line in between
the meter and the antenna, then you have to connect the antenna
to the load end of the meter directly.

If there is a tuner or matching network in the line then the meter
will indicate SWR on the line between the transmitter and the tuner -
provided the meter is placed next to the tuner.

Tuners have nothing to do with the issue.

You can put a 1956 Buick on the load side of the meter; you still
read SWR of the system at the point of measurement.

It is you that is trying to confuse the issue with arm waving.

When there is no appreciable length of line between transmitter and
tuner (as is the very common case) there is no line on which to
measure SWR. But the meter will indicate an SWR - and tells lies.

Babbling nonsense.

But there's nothing to worry about just because the meter is
indicating SWR nonsense. The meter is telling you what you really
want to know, its exactly why you placed it there - whether or not
the transmitter is loaded with 50 ohms.

That is not what I would want to know.

I know the output impedance of the transmitter and the line (assuming
it is good) impedance.

What I want to know is the antenna SWR and the measurement of that is
trivial though it seems to have you totally confused.

----
Reg.


--
Jim Pennino

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