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-   -   Antennas 101 (https://www.radiobanter.com/antenna/72609-antennas-101-a.html)

Ian White GM3SEK June 12th 05 10:23 PM

Richard Fry wrote:

... I am asking for comments on what I wrote --

________________

Thanks to all who responded. Now to process those responses.

RF

One final comment: this thread shows how difficult it can be to distil a
complex subject down to a few paragraphs, without making generalizations
that will sometimes be incorrect.

It can never be done in a single pass, so all credit for making the
effort and for taking the comments on board.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Cecil Moore June 12th 05 11:59 PM

Roy Lewallen wrote:
In the steady
state, there is no test which can be devised that can distinguish an
antenna (including feedline, if desired) from a black box containing
lumped components -- a lumped component circuit(*).


You can't distinguish between a resonant 1/2WL dipole and a dummy load
using a field strength meter? :-) You can't distinguish between a
dummy load impedor and a resonant dipole impedance? How about just
looking to see if a physical impedor exists? Those two impedances even
have different definitions in the IEEE Dictionary.

Cecil, if you feel a need to expound yet more on your theories, please
do so in one of the many threads you've come to dominate already, start
a new one, or concentrate your efforts on your forthcoming QEX article.
I hope you'll let us try and make an objective and hopefully helpful
contribution from time to time on this newsgroup without your constantly
attempting to steer the discussion to your theories.


Their not my theories, Roy. For instance,
the IEEE Dictionary distinguishes between the (virtual) feedpoint
impedance of a resonant antenna and the impedance of an impedor,
e.g. a dummy load. Those two impedances have *different* definitions.
A dummy load impedor is the *cause* of the load V/I ratio. The
resistance of a resonant 50 ohm antenna is the *effect* of the
feedpoint (superposed-V/superposed-I) ratio. Isn't it past time
for completely ignoring cause and effect?
--
73, Cecil http://www.qsl.net/w5dxp

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John Smith June 13th 05 12:16 AM

Ian:

AYE!!!

And being the uncouth slob I am, and holding the motto, "Whatever
works!" I get my butt kicked a lot... frown

John

"Ian White GM3SEK" wrote in message
...
Richard Fry wrote:

... I am asking for comments on what I wrote --

________________

Thanks to all who responded. Now to process those responses.

RF

One final comment: this thread shows how difficult it can be to distil
a complex subject down to a few paragraphs, without making
generalizations that will sometimes be incorrect.

It can never be done in a single pass, so all credit for making the
effort and for taking the comments on board.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek




Roy Lewallen June 13th 05 01:27 AM

And he's off again. I gained a lot of peace when I put "John Smith" and
Jesus as the very first two entries in my filter list some time ago. You
now have the distinction of being the third -- just below Jesus.

It's really a shame -- on those rare instances where you can be coaxed
into commenting without being compelled to steer the subject to your
favorite obsession, you really do have a lot to offer. But the duty
cycle is just too low -- it's not worth it to me. Bye.

Roy Lewallen, W7EL

Cecil Moore wrote:
Roy Lewallen wrote:

In the steady state, there is no test which can be devised that can
distinguish an antenna (including feedline, if desired) from a black
box containing lumped components -- a lumped component circuit(*).



You can't distinguish between a resonant 1/2WL dipole and a dummy load
using a field strength meter? :-) You can't distinguish between a
dummy load impedor and a resonant dipole impedance? How about just
looking to see if a physical impedor exists? Those two impedances even
have different definitions in the IEEE Dictionary.

Cecil, if you feel a need to expound yet more on your theories, please
do so in one of the many threads you've come to dominate already,
start a new one, or concentrate your efforts on your forthcoming QEX
article. I hope you'll let us try and make an objective and hopefully
helpful contribution from time to time on this newsgroup without your
constantly attempting to steer the discussion to your theories.



Their not my theories, Roy. For instance,
the IEEE Dictionary distinguishes between the (virtual) feedpoint
impedance of a resonant antenna and the impedance of an impedor,
e.g. a dummy load. Those two impedances have *different* definitions.
A dummy load impedor is the *cause* of the load V/I ratio. The
resistance of a resonant 50 ohm antenna is the *effect* of the
feedpoint (superposed-V/superposed-I) ratio. Isn't it past time
for completely ignoring cause and effect?


Cecil Moore June 13th 05 05:16 AM

Roy Lewallen wrote:
It's really a shame -- on those rare instances where you can be coaxed
into commenting without being compelled to steer the subject to your
favorite obsession, you really do have a lot to offer. But the duty
cycle is just too low -- it's not worth it to me. Bye.


Well, before you go, Roy, chew on this one. The s11 reflection
coefficient at the feedpoint of a 1/2WL dipole is about 0.85
--
73, Cecil http://www.qsl.net/w5dxp


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Cecil Moore June 13th 05 05:29 AM

Cecil Moore wrote:

Roy Lewallen wrote:
It's really a shame -- on those rare instances where you can be coaxed
into commenting without being compelled to steer the subject to your
favorite obsession, you really do have a lot to offer. But the duty
cycle is just too low -- it's not worth it to me. Bye.


I apologize for barbecuing those sacred cows.

Well, before you go, Roy, chew on this one. The s11 reflection
coefficient at the feedpoint of a 1/2WL dipole is about 0.85

when fed with 50 ohm coax.
--
73, Cecil http://www.qsl.net/w5dxp


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John Smith June 13th 05 06:18 AM

.... deep within the pits of-- rec.radio.amateur.antenna.hell-- John
Smith moves over on the bench, making room for Cecil...

Warmest regards,
John

"Cecil Moore" wrote in message
...
Cecil Moore wrote:

Roy Lewallen wrote:
It's really a shame -- on those rare instances where you can be
coaxed into commenting without being compelled to steer the subject
to your favorite obsession, you really do have a lot to offer. But
the duty cycle is just too low -- it's not worth it to me. Bye.


I apologize for barbecuing those sacred cows.

Well, before you go, Roy, chew on this one. The s11 reflection
coefficient at the feedpoint of a 1/2WL dipole is about 0.85

when fed with 50 ohm coax.
--
73, Cecil http://www.qsl.net/w5dxp


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet
News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World!
100,000 Newsgroups

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Cecil Moore June 13th 05 12:47 PM

John Smith wrote:
... deep within the pits of-- rec.radio.amateur.antenna.hell-- John
Smith moves over on the bench, making room for Cecil...


I guess some religions forbid barbecuing sacred cows.
--
73, Cecil http://www.qsl.net/w5dxp


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Jim Kelley June 13th 05 08:22 PM

Cecil Moore wrote:

John Smith wrote:

... deep within the pits of-- rec.radio.amateur.antenna.hell-- John
Smith moves over on the bench, making room for Cecil...



I guess some religions forbid barbecuing sacred cows.


Thankfully, nature forbids flying cows - and pigs. :-)

Squelch on.

ac6xg


Cecil Moore June 13th 05 09:18 PM

Jim Kelley wrote:

Cecil Moore wrote:
I guess some religions forbid barbecuing sacred cows.


Thankfully, nature forbids flying cows - and pigs. :-)


Hey Jim, welcome back. I have a thread waiting for you. It's titled
"Thin Film Example" and asks you to explain where the energy and
the momentum in the thin-film internal reflected wave goes. Enjoy. :-)
--
73, Cecil http://www.qsl.net/w5dxp

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