Guy from university physics dept. makes claims toincite/provok...
 

Art, KB9MZ.....XG wrote:
"The Yagi was invented by Japanese in the early 1920 where America
embraced the invention and where Japan did not."

Close but no cigar. Truth Squad time again.

The 3rd edition of Kraus` "Antennas" has the Yagi-Uda Story beginning on
page 246. It Says:
"This led to the publication of a series of articles from March 1926 to
July 1929) in the Journal of the Institute of Electrical Engineers of
Japan titled "On the Wireless Beam of Short Electric Waves." (Uda-1)."

Best regards, Richard Harrison, KB5WZI

Guy from university physics dept. makes claims to incite/provoke amateurs!
 

"art" wrote
The antenna from the University is resonant,
tho less efficient than ideal.
_________________

Reprise for Art: The efficiency of an antenna system in radiating the
power available at the antenna end of the transmission line connected to its
feedpoint does not depend on whether or not the radiator itself is naturally
resonant.

It depends on...

1) the ratio of the radiation resistance of the radiating sections of the
antenna to the sum of that radiation resistance with all other r-f
resistances in the antenna system. The pure radiation resistance of an
antenna depends on the effective length//configuration of, and the r-f
current distribution along the conductors exposed to space -- but not those
of any matching devices used in the system design (wherever located).

2) the degree of impedance match existing between the antenna feedpoint and
the source (normally, a transmission line, including any matching network
there).

The DLM uses matching components within the length of a short vertical
radiator with the goals of canceling the high capacitive reactance of this
electrically short radiator, and changing the current distribution along the
radiator for an average value higher than provided by base loading.

So for the same losses in the r-f ground system, the DLM could have somewhat
better system radiation efficiency than a base-loaded monopole of the same
physical height. But good system efficiency would still be heavily
dependent on the quality of the r-f ground used with it (just as in a
"standard" monopole).

This is not a revolutionary concept, as mid- and top-loading techniques have
been used with vertical monopoles for many decades.

RF

Guy from university physics dept. makes claims toincite/provok...
 

Art wrote:
"I suppose ham radio reflects the veterans of WW2 there many of those
who were doers are gradually dying off leaving former CBers in the
majority."
I qualify for all of the above, WW-2 overseas veteran, radio amateur,
CBer, but I`m not dead yet. I also had a 1st class phone license and an
E.E. degree, among others.

Best regards, Richard Harrison, KB5WZI1

Guy from university physics dept. makes claims toincite/provok...
 

Art wrote:
"Now I have a mantra that if it is "resonant and in a state of
equilibriun" it is what I call a Gaussian antenna."

Yes, and the question still remains, are the lyrics sung because they
are too silly to be repeated without the music?

Best regards, Richard Harrison. KB5WZI

Guy from university physics dept. makes claims to incite/provok...
 

On 4 Jul, 08:07, (Richard Harrison) wrote:
Art, KB9MZ.....XG wrote:

"The Yagi was invented by Japanese in the early 1920 where America
embraced the invention and where Japan did not."

Close but no cigar. Truth Squad time again.

The 3rd edition of Kraus` "Antennas" has the Yagi-Uda Story beginning on
page 246. It Says:
"This led to the publication of a series of articles from March 1926 to
July 1929) in the Journal of the Institute of Electrical Engineers of
Japan titled "On the Wireless Beam of Short Electric Waves." (Uda-1)."

Best regards, Richard Harrison, KB5WZI


The truth!
Where is the lie?

Guy from university physics dept. makes claims to incite/provoke amateurs!
 

On 4 Jul, 08:14, "Richard Fry" wrote:
"art" wrote The antenna from the University is resonant,
tho less efficient than ideal.

_________________

Reprise for Art: The efficiency of an antenna system in radiating the
power available at the antenna end of the transmission line connected to its
feedpoint does not depend on whether or not the radiator itself is naturally
resonant.

It depends on...

1) the ratio of the radiation resistance of the radiating sections of the
antenna to the sum of that radiation resistance with all other r-f
resistances in the antenna system. The pure radiation resistance of an
antenna depends on the effective length//configuration of, and the r-f
current distribution along the conductors exposed to space -- but not those
of any matching devices used in the system design (wherever located).

2) the degree of impedance match existing between the antenna feedpoint and
the source (normally, a transmission line, including any matching network
there).

The DLM uses matching components within the length of a short vertical
radiator with the goals of canceling the high capacitive reactance of this
electrically short radiator, and changing the current distribution along the
radiator for an average value higher than provided by base loading.

So for the same losses in the r-f ground system, the DLM could have somewhat
better system radiation efficiency than a base-loaded monopole of the same
physical height. But good system efficiency would still be heavily
dependent on the quality of the r-f ground used with it (just as in a
"standard" monopole).

This is not a revolutionary concept, as mid- and top-loading techniques have
been used with vertical monopoles for many decades.

RF

The term " cancelling " is not correct tho people seem to be happy
with it.
In fact is it is not CANCELLING anything as it is actually adding to
provide
a state of equilibrium. Big difference
Art

Guy from university physics dept. makes claims toincite/provok...
 

Art wrote:
"Where is the lie?"
The inventors were not without honor on their own land!

Best regards, Richard Harrison, KB5WZI

Guy from university physics dept. makes claims to incite/provok...
 

On 4 Jul, 10:11, (Richard Harrison) wrote:
Art wrote:

"Where is the lie?"
The inventors were not without honor on their own land!

Best regards, Richard Harrison, KB5WZI

Bull, They were ignored.Japan had not implimented the idea
up till such time that one was captured from the Allies.
Pretty much the same as with the inventor of the concept
"Just in time" for Industry. Reverred in Japan and
ignored in the U.S.until the Japanese "invasion."
What I said is NOT A LIE. Unfortunately Kraus must have died
thus preventing its addition to his book. Seems like you need
to get a book that is up to date and relavent before you call
me a LIAR.

Guy from university physics dept. makes claims toincite/provok...
 

Art wrote:
"Bull. They were ignored. Japan had not implemented the idea up till
such time that one was captured from the allies."

Wikiipedia history confirms Art`s version of the Yagi`s story. I was
wrong. I appologize. The Japanese paid little attention to their own
invention. How did we get so lucky? Sorry for accusing Art of Yagi
misinformation.

Now, I think we are agreed that resonance is a nonreactive load. I don`t
know what Art means by "equilibrium" in regard to the dynamic electrical
characteristics of an antenna. We know that the same quantity can be
added to both sides of an equation and just like a scale balance, no
change in value occurs. Twenty questions should not be required to get
an answer.

Best regards, Richard Harrison, KB5WZI

Guy from university physics dept. makes claims to incite/provoke amateurs!
 

"art" wrote

The term " cancelling " is not correct tho people seem to be happy
with it. In fact is it is not CANCELLING anything as it is actually
adding to provide a state of equilibrium. Big difference.
_____________

That's what you meant by equilibrium !

Kindly note that "equilibrium" (or resonance) does not need to be an
attribute of the radiator itself, only a desirable attribute of the complete
antenna system.

RF