What effect does a tuner have at the antenna?
 

Cecil Moore wrote:

The myth is undoubtedly that the implied point of view is either popular
or developing.

From QRZ.com regarding tuners:

"The tuner has absolutely no effect at the antenna."

From eHam.net regarding tuners:

"Does nothing. The tuner as the other poster said,
just makes your radio happy."

The tuner doesn`t change the antenna specification, e.g. gain,
impedance, or pattern.
If you buy a beam antenna you will get this data, and the pattern of the
antenna is most time a free room pattern.

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.

--
DK
DJ4PB

What effect does a tuner have at the antenna?
 

....100% efficient? The only thing I have ever had that was 100%
efficient was my 'Ex', which she pointed out to me quite often. So,
using a tuner that got just a tiny bit 'warm' from it's inefficiency
just wasn't/isn't that big'a deal. When it became noticeably 'warm',
it was because I was trying to match something that just was not very
close to reasonable. Then again, it sort of depends on the tuner you
happen to be using, it's 'usable' impedance matching range, just how
'robust' the thing happens to be built, and what you are trying to do
with it to start with. There are limits. How often you approach
those limits sort of defines how much heat you will see, they make
pretty nice coffee warmers at times ;), not the best idea in the
world, but...
- 'Doc

And just for 'grins', for those who do not 'approve' of using a tuner,
what do you think those gama, delta, and other variety of thingys on
the feed point of that beam are?
(if that don't stir the 'worm soup' up a little, I just haven't had
enough coffee yet. I'm still warming it on the tuner.)
:)

What effect does a tuner have at the antenna?
 

AI4QJ wrote:
"Cecil Moore" wrote in message
If we adjusted the tuner for maximum forward power
at the antenna, wouldn't that mean the tuner was
properly tuned for a Z0-match at the transmitter?

I think it would be essentially true for today's FET transmitters that
automatically limit output power when the Z0 is not matched, but not for any
reason having to do with transmission line theory.

Let's see what is wrong with the following reasoning:

1. Maximum power is delivered to a mismatched load
when the forward power is at a maximum.

2. Maximum available power is delivered to the load
when the source sees its designed-for impedance, e.g.
is Z0-matched.

Why wouldn't the forward power at the antenna be
maximized by a Z0-match at the source while the
tuner is being adjusted?
--
73, Cecil http://www.w5dxp.com

What effect does a tuner have at the antenna?
 

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.
--
73, Cecil http://www.w5dxp.com

What effect does a tuner have at the antenna?
 

Cecil Moore 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.

The power at the antenna will also be measurable if you decide to bypass
the tuner.
If you have a good match you don`t need a tuner.
But most of the transmitters don`t work correct with a high swr.
Even if they would the best match will get the most power into the
antenna.
The tuner at the transmitter doesn`t change the impedance of the
antenna. It also doesn`t change the gain or the pattern of the antenna.
DK

What effect does a tuner have at the antenna?
 

On Jun 4, 12:33*pm, Cecil Moore wrote:
A popular myth is developing that the tuner has no effect
at the antenna feedpoint and the only goal is to make the
transmitter "happy". My question is: if we monitored
only the forward current or forward power at the antenna
feedpoint, could we still adjust the tuner? If the answer
is "yes", the myth is false.
--
73, Cecil *http://www.w5dxp.com

I the early books I have that is how things were tuned up. The
antenna was dirrectly tapped on to the tank coil. Adjusted for
maximum antenna current. No one had heard of swr meters. Antennas
worked just fine. Today the antenna tuner resonates the antenna. No
antenna tuner? Then no resonanting the antenna. You have to take what
the antenna gives.

john w9zy

What effect does a tuner have at the antenna?
 

"Cecil Moore" ha scritto nel messaggio
...
A popular myth is developing that the tuner has no effect
at the antenna feedpoint and the only goal is to make the
transmitter "happy". My question is: if we monitored
only the forward current or forward power at the antenna
feedpoint, could we still adjust the tuner? If the answer
is "yes", the myth is false.
--
73, Cecil http://www.w5dxp.com

What effect does a tuner have at the antenna?
 

"Cecil Moore" ha scritto nel messaggio
...
A popular myth is developing that the tuner has no effect
at the antenna feedpoint and the only goal is to make the
transmitter "happy". My question is: if we monitored
only the forward current or forward power at the antenna
feedpoint, could we still adjust the tuner? If the answer
is "yes", the myth is false.
--
73, Cecil http://www.w5dxp.com

If somebody really wrote that "the tuner has no effect at the antenna
feedpoint", there are two cases:

1) either he meant to correctly say that, adjusting the tuner, the impedance
seen at the antenna terminations - or any other antenna property - does not
change (independently of whether the tuner is placed at the transmitter end or
at the antenna end). If so, it is just a matter of bad wording, and I would be
tempted to say that his english is even worse than my non-mother tongue one

2) or he has a poor understanding of transmission lines and antenna theory

73

Tony I0JX

What effect does a tuner have at the antenna?
 

"Cecil Moore" wrote in message
...
A popular myth is developing that the tuner has no effect
at the antenna feedpoint and the only goal is to make the
transmitter "happy". My question is: if we monitored
only the forward current or forward power at the antenna
feedpoint, could we still adjust the tuner? If the answer
is "yes", the myth is false.
--
73, Cecil http://www.w5dxp.com

Everyone makes more of a tuner than what it is. If all transmitters were
designed to work into very wide loads the tuners would not be needed. Tubes
have an impedance of around 1000 to 4000 ohms and must be matched to 50 ohm
coax (usual ham antenna design) or some other combination of resistance and
reactance. The transisitors must be matched from a very low value (under 10
ohms usually) to a higher impedance.
Many transmitters now in use are for only 50 ohm output (fixed tuning) or a
small range (maybe 3:1 for some amps) if they do have an adjustiable
tuning.

There are some antenna designs that fall way out of the 50 ohm design
inpedance so some way must be made to match the inpedances for maximum power
transfer.

Take an amplifier that has a pi-L network built in. If it is adjusted for
max power out , and an amp with a pi network with an external L network to
match an antenna, what is the differance ?

What effect does a tuner have at the antenna?
 

Antonio Vernucci wrote:
"Cecil Moore" ha scritto nel messaggio
...
A popular myth is developing that the tuner has no effect
at the antenna feedpoint and the only goal is to make the
transmitter "happy". My question is: if we monitored
only the forward current or forward power at the antenna
feedpoint, could we still adjust the tuner? If the answer
is "yes", the myth is false.
--
73, Cecil http://www.w5dxp.com

If somebody really wrote that "the tuner has no effect at the antenna
feedpoint", there are two cases:

1) either he meant to correctly say that, adjusting the tuner, the
impedance seen at the antenna terminations - or any other antenna
property - does not change (independently of whether the tuner is placed
at the transmitter end or at the antenna end). If so, it is just a
matter of bad wording, and I would be tempted to say that his english is
even worse than my non-mother tongue one

2) or he has a poor understanding of transmission lines and antenna theory

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

- 73 de Mike N3LI -