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Old December 5th 04, 01:18 AM
Telamon
 
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In article N6Urd.1972$Ro.742@lakeread02,
"Jack Painter" wrote:

"Telamon" wrote
"digitania" wrote:


3) Can I then attach multiple antenna tuners to that single
antenna and optimize each receiver's feed?


No. Most receivers have the same input impedance - about 50 ohms so you
would only need one tuner. The tuner resonates the antenna at some
frequency of interest.
--
Telamon
Ventura, California


Sorry there buddy, you are mistaken in that comment about resonating an
antenna. Tuners don't "resonate" anything, they simply fool a transmitter
into thinking it has a good impedance match. This is done between the tuner
and the transmitter only, even if ridiculous impedance and reactance
actually exists on several parts of the feedline and/or antenna. In that
case, the tuner will have to dissipate a lot of heat that the antenna system
throws back at it. When a receiver is connected to a tuner, the tuner
likewise simply balances the piece of line between itself and the receiver
and nothing else. This often improves reception, but it has no affect on the
antenna whatsoever.


Sorry to give you and maybe other people the wrong impression but that
is the problem with definitions. A tuner resides between the antenna and
the transmission line to the radio. The tuner has reactive components
that together with the antenna element form a resonate circuit which
will resonate at some frequency. The tuner design will depend on the
antenna type and could be as simple as a capacitor reacting with the
antenna element inductance.

If you are a ham you might have thought I was referring to an impedance
matching unit which prevents a transmitter from seeing an unmatched load
with the resultant SWR.

Or you might have thought I was referring to a high-pass, low-pass or
bandpass filter some people use for SWL'ing but no, I was referring to
a unit that actually resonates the antenna which was an answer to one of
the original posters questions if I understood him correctly.

--
Telamon
Ventura, California