What effect does a tuner have at the antenna?
 

Cecil Moore wrote:
Dieter Kiel wrote:
As the tuner is used to match the impedance of the radio to the line it
will effect the power getting to the antenna or the signal received from
the antenna if it is passed through the tuner.

If the power getting to the antenna is measurable, then
the tuner is causing something to happen at the antenna.
It is doing more than just making the transmitter happy.
After all, a dummy load makes the transmitter just as
happy as a tuner.

Cecil;

An antenna tuner does not and can not and will not make any physical or
electrical changes to any antenna it is attached to. It will, however,
make electrical changes to an "ANTENNA SYSTEM" such that a transmitter
or receiver will react to the system more efficiently.

Take a dummy load that exhibits a characteristic impedance of say 75
ohms and hook it up to a transmitter that exhibits a characteristic
impedance of 50 ohms. I guarantee that the transmitter won't like it as
well as a dummy load that exhibits a characteristic impedance of 50
ohms. All impedances are purely resistive with no inductive component.
Place a tuner in the circuit and adjust it for best conditions. The
transmitter will think it is looking at 50 ohms not 75.

Dave WD9BDZ

What effect does a tuner have at the antenna?
 

What effect does a tuner have at the antenna?
 

Michael Coslo wrote:
Yeah. This is probably the first time some random poster over at QRZ or
Eham has been wrong! 8^)

What is troubling is that the myth seems to be approaching
50% of the posters. If all an antenna tuner does is make the
transmitter happy, it is no better than a dummy load.
--
73, Cecil http://www.w5dxp.com

What effect does a tuner have at the antenna?
 

David G. Nagel wrote:
An antenna tuner does not and can not and will not make any physical or
electrical changes to any antenna it is attached to.

Seems to me that delivery of the maximum available power
to the radiation resistance of an antenna is certainly
a physical/electrical change capable, in the extreme, of
melting the antenna.

Consider what a 1kw amp could do to a 40m hamstick used
on 75m when matched with a 1kw antenna tuner.
--
73, Cecil http://www.w5dxp.com

What effect does a tuner have at the antenna?
 

"David G. Nagel" wrote in message
...
wrote:
For more grins, what do you think the "LOAD" and "TUNE" knobs on an older
tube transmitter are? They match the output power tube impedance to the
antenna system impedance. If you don't believe me mistune a tube
transmitter and feel the warmth come from the finals. Have a spare in
stock for when you are done.

Dave WD9BDZ

I think I am trying to say the same thing.

One has to define where the matching system of the final amplifier stops and
the antenna system starts. I look at an antenna tuner that is within a few
feet of the transmitter as an extention of the matching network between the
amplifier device (tube or transistor) and the load which starts with the
transmission line.

If the antenna tuner is actually at the antenna, then it is a matching
device for the antenna and not in the scope of this discussion.

Is the automatic internal antenna tuner such as in my Icom746 pro really an
antenna tuner or is it just taking the place of some knobs that I could turn
such as in a Heathkit sb100 ? All that is being done in either case is to
match the amplifing device to whatever load is put to it.
I thnk it is just a mater of what someone wants to call it at the time.

What effect does a tuner have at the antenna?
 

Cecil Moore wrote:
David G. Nagel wrote:
An antenna tuner does not and can not and will not make any physical
or electrical changes to any antenna it is attached to.

Seems to me that delivery of the maximum available power
to the radiation resistance of an antenna is certainly
a physical/electrical change capable, in the extreme, of
melting the antenna.

Consider what a 1kw amp could do to a 40m hamstick used
on 75m when matched with a 1kw antenna tuner.

Cecil;

How much change in physical length or diameter of wire does an antenna
tuner make to an antenna?

Dave

What effect does a tuner have at the antenna?
 

David G. Nagel wrote:
Cecil Moore wrote:
Consider what a 1kw amp could do to a 40m hamstick used
on 75m when matched with a 1kw antenna tuner.

How much change in physical length or diameter of wire does an antenna
tuner make to an antenna?

In the above example, it vaporizes the hamstick wire.
IMO, that is quite a change.
--
73, Cecil http://www.w5dxp.com

What effect does a tuner have at the antenna?
 

AI4QJ wrote:
You can take advantage of the "information" provided
by the transmitter, with reference to its Z0 match condition, by merely
observing the maximum available output power.

The point is, it can be monitored *at the antenna*
thus proving that a tuner does indeed have an effect
at the antenna.
--
73, Cecil http://www.w5dxp.com

What effect does a tuner have at the antenna?
 

Cecil Moore wrote:
AI4QJ wrote:

You can take advantage of the "information" provided by the
transmitter, with reference to its Z0 match condition, by merely
observing the maximum available output power.


The point is, it can be monitored *at the antenna*
thus proving that a tuner does indeed have an effect
at the antenna.

An effect "at" the antenna is not the same as an effect "on" the
antenna. Which did you mean in your OP?
Alan

What effect does a tuner have at the antenna?
 

Alan Peake wrote:
An effect "at" the antenna is not the same as an effect "on" the
antenna. Which did you mean in your OP?

The subject line says it all - "at the antenna".
--
73, Cecil http://www.w5dxp.com