Antenna tuners

[Gary Peterson]

You are in good company with Walter Maxwell, W2DU, now silent key.  Maxwell was an engineer at RCA.  He designed the antennas on several earth orbiting satellites and the antenna on the Lunar Rover.  He explained this quite succinctly in his book Reflections (all three editions), by use of the conjugate matching theorem.  As I recall, that chapter in his book (peer reviewed by the RCA engineering department) was called My Antenna Tuner Tunes My Antenna.

Gary, K0CX

But if the "tuner" is an LC network, like an adjustable L network, T network, Pi network, or a linked-coupled network, then I strongly disagree.
A tuner is a 2-port network. A transmission line is also a 2-port network. Both networks obey reciprocity, meaning that what you do to one port of the network will have a direct influence on the opposite end.
That being said, if an antenna exhibits a complex impedance at our frequency of interest, and that behavior can be corrected (brought to resonance) by the application of a particular value of reactance at the antenna's feedpoint, then that application of reactance can, for reasons of convenience, be made at the "shack end" of the transmission line. As such, the "tuner" in the shack is really "tuning" the antenna!
John, KD2BD
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[ke9uw]

Wasn't there a debate between Maxwell and Walter Bruene (designed the Collins 30L1) on the conjugate match...I think Bruene disagreed with the popular notion of a conjugate match.

Jack BMW Motorcycles
Chuck KE9UW
[hidden email]

Sent from my iPad

> On Jul 18, 2020, at 3:01 PM, Gary Peterson <[hidden email]> wrote:
>
> You are in good company with Walter Maxwell, W2DU, now silent key.  Maxwell was an engineer at RCA.  He designed the antennas on several earth orbiting satellites and the antenna on the Lunar Rover.  He explained this quite succinctly in his book Reflections (all three editions), by use of the conjugate matching theorem.  As I recall, that chapter in his book (peer reviewed by the RCA engineering department) was called My Antenna Tuner Tunes My Antenna.
>
> Gary, K0CX
>
> But if the "tuner" is an LC network, like an adjustable L network, T network, Pi network, or a linked-coupled network, then I strongly disagree.
> A tuner is a 2-port network. A transmission line is also a 2-port network. Both networks obey reciprocity, meaning that what you do to one port of the network will have a direct influence on the opposite end.
> That being said, if an antenna exhibits a complex impedance at our frequency of interest, and that behavior can be corrected (brought to resonance) by the application of a particular value of reactance at the antenna's feedpoint, then that application of reactance can, for reasons of convenience, be made at the "shack end" of the transmission line. As such, the "tuner" in the shack is really "tuning" the antenna!
> John, KD2BD
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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[k6dgw]

More than just them.  Steve, K6OIK, who has presented at a number of
past Pacificons speaks about the Myths of Conjugate Matching in a
Pacificon presentation from 2011 at
https://www.fars.k6ya.org/docs/Conjugate-Match-Myths.pdf It begins on
page 20.  This is Dr. Stearns home turf, it can be a little technically
dense in places.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 7/18/2020 3:46 PM, hawley, charles j jr wrote:
> Wasn't there a debate between Maxwell and Walter Bruene (designed the Collins 30L1) on the conjugate match...I think Bruene disagreed with the popular notion of a conjugate match.
>
> Jack BMW Motorcycles
> Chuck KE9UW
> [hidden email]
>
>

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