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Old December 27th 05, 06:23 PM posted to rec.radio.amateur.antenna
Reg Edwards
 
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Default If the ideal lenght of an antenna is 1/4 Wave lenght then way are the Car Cellular antennas are longer then this ?


"Richard Fry" wrote
"Reg Edwards" wrote
Just to start an argument, why is it that EZNEC shows zero gain

for a
vertical antenna in the horizontal plane? Whereas, all your

diagrams
show maximum gain along the horizontal.

____________

EZNEC shows the same patterns/gains as in the plots I posted,
when its models are set up correctly.

RF

========================================

The model for a simple vertical above ground is simple enough.

Perhaps YOUR way is incorrect if the pattern disagrees so strongly
with EZNEC.
----
Reg.


  #22   Report Post  
Old December 27th 05, 08:53 PM posted to rec.radio.amateur.antenna
Richard Fry
 
Posts: n/a
Default If the ideal lenght of an antenna is 1/4 Wave lenght then way are the Car Cellular antennas are longer then this ?

"Reg Edwards" wrote
"Richard Fry" wrote
"Reg Edwards" wrote
Just to start an argument, why is it that EZNEC shows zero gain

for a vertical antenna in the horizontal plane? Whereas, all your
diagrams show maximum gain along the horizontal.
____________

EZNEC shows the same patterns/gains as in the plots I posted,
when its models are set up correctly.

RF

========================================

The model for a simple vertical above ground is simple enough.

Perhaps YOUR way is incorrect if the pattern disagrees so strongly
with EZNEC.
----
Reg.

_______________

Reg,

My models agree with theory and measured results, as have been developed and
well-proven for 60+ years in the broadcast industry.

If you doubt my plots, why not send them to Roy Lewallen ask for his
comments? You might also ask him to tell you how to model these
configurations properly using EZNEC.

I'd explain it, but probably that wouldn't be acceptable to you (plus you
didn't ask me).

RF

  #23   Report Post  
Old December 27th 05, 09:12 PM posted to rec.radio.amateur.antenna
Roy Lewallen
 
Posts: n/a
Default If the ideal lenght of an antenna is 1/4 Wave lenght then wayare the Car Cellular antennas are longer then this ?

Reg Edwards wrote:
Just to start an argument,


Things are even duller than usual in Rowley Regis, I see.

why is it that EZNEC shows zero gain for a
vertical antenna in the horizontal plane? Whereas, all your diagrams
show maximum gain along the horizontal.


C'mon Reg, it's only been three months since you last asked this and got
it answered(1). The time before that was four years earlier(2), and
before that multiple times going back at least to 1998(3). At the rate
you're going, you'll be asking it weekly before long. Getting tired of
promoting "TLI"s, grumping at "Gurus" (while carefully excluding
yourself, of course), grousing about Americans, and asking "Who's
Kraus"? C'mon, be original. Surely you can think of a new topic to keep
you awake on those long, boring evenings. I've got an idea -- maybe you
can use your knowledge to actually help some of the folks who ask
serious questions on this newsgroup.

For anyone who wants an answer to Reg's perennial question, use
groups.google.com to look up the following threads on this newsgroup,
where Reg has asked the same question and where it's been answered:

(1) "best HF antenna system next to a trailer?", Sept. 2005
(2) "40M Delta Loop Advice Needed:", May 2001
(3) "Raised V's burried ground systems." [sic], Feb. 2000
"Ground Radial system comparisons", April 1999
"Is there", Aug. 1998
"Better for DXing: Beam or vertical?", Aug. 1998

Roy Lewallen, W7EL
  #24   Report Post  
Old December 28th 05, 06:36 AM posted to rec.radio.amateur.antenna
Reg Edwards
 
Posts: n/a
Default If the ideal lenght of an antenna is 1/4 Wave lenght then way are the Car Cellular antennas are longer then this ?

Roy, you'll just have to accept the fact that I'm peculiar. But no
more peculiar than other frequenters of this newsgroup. I don't think
I do much damage.
----
Reg.


  #25   Report Post  
Old December 28th 05, 04:04 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default If the ideal lenght of an antenna is 1/4 Wave lenght then wayare the Car Cellular antennas are longer then this ?

Reg Edwards wrote:
Roy, you'll just have to accept the fact that I'm peculiar. But no
more peculiar than other frequenters of this newsgroup.


How's this for peculiar? :-)

"The movement of energy within the line is complex; in the
abbreviated analysis I've had time to do so far, it sloshes
back and forth in regions within the line."
--
73, Cecil http://www.qsl.net/w5dxp


  #26   Report Post  
Old December 29th 05, 06:39 AM posted to rec.radio.amateur.antenna
Reg Edwards
 
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Default If the ideal lenght of an antenna is 1/4 Wave lenght then way are the Car Cellular antennas are longer then this ?


Richard, I thank you for your time and trouble expended in trying to
educate me regarding the field strength from a 1 Kw transmitter at a
distance of 1 Km.

Your efforts, of course, will not be wasted on other readers of this
newsgroup. Very good stuff!

But you have misunderstood my attitude towards this discussion.

As I have said before, amateurs and professionals alike, all suffer
from delusions of accuracy. The uncertainty in prediction of field
strength of groundwaves can amount to 10 or 15 dB or even more at
extreme distances.

When I say my program correctly predicts a field strength of 300
millivolts per metre at a distance of 1 Km from a 1 Kw transmitter,
nobody can disprove it. Even the 'bibles' state it as a matter of
fact. But we all know how much faith can be placed in 'bibles'.

To be of use, all measurements should be associated with an
uncertainty. Only then can the originators be judged to understand
what they are waffling about.

Thank you for your interest.
----
Reg, G4FGQ.


  #27   Report Post  
Old December 29th 05, 02:23 PM posted to rec.radio.amateur.antenna
Richard Fry
 
Posts: n/a
Default If the ideal lenght of an antenna is 1/4 Wave lenght then way are the Car Cellular antennas are longer then this ?

"Reg Edwards"
When I say my program correctly predicts a field strength of 300
millivolts per metre at a distance of 1 Km from a 1 Kw transmitter,
nobody can disprove it. Even the 'bibles' state it as a matter of
fact. But we all know how much faith can be placed in 'bibles'.

To be of use, all measurements should be associated with an
uncertainty. Only then can the originators be judged to understand
what they are waffling about.

______________

Interesting point of view, Reg.

The correct application of physical laws disproves your contention, and the
equations that do it are not difficult. Here they a

E = SQRT(49.2*P)/D

where E = Peak inverse (free-space) field from a self-resonant,
1/2-wave dipole (volts/meter)
D = Distance (meters)

As radiation from a vertical antenna with its base at ground level is
confined to one hemisphere, field strength at that distance over a perfect,
infinite, flat "ground" plane is E * SQRT(2).

This generates the value of the maximum possible field from a perfect
1/4-wave vertical radiator over a perfect ground plane, which has been
proven and used for many decades in the broadcast industry. This is the
groundwave field that then is subject to various propagation losses related
to earth conductivity, diffraction etc over long paths, once the radiation
has been launched. N.B. -- at a distance of 1 km, such losses are
negligible for the typical broadcast vertical with its 120 buried radials,
regardless of ground conductivity.

Why not use the formulae in your program that actually generates the correct
value, instead of just saying it does, or implying that your approach is
"good enough?"

RF

  #28   Report Post  
Old December 29th 05, 03:31 PM posted to rec.radio.amateur.antenna
J. Mc Laughlin
 
Posts: n/a
Default If the ideal lenght of an antenna is 1/4 Wave lenght then way are the Car Cellular antennas are longer then this ?

As someone who is contemplating retirement from formal teaching duties after
42 years of teaching EE, Reg provides me an important bit of instruction
about retirement. All of my life, I have noted those I wish to emulate and
those who I wish not to emulate.
More experienced people (read: old folk) are able to contribute stories
of things to do and not to do. Reg and several others here have done just
that. Many important or practical parts of the art are not easy to find
even with the WEB. Knowledge should be cumulative.
On the other hand, tossing a stick of dynamite into the lake to see how
many fish come to the surface (this time) is in a different category.
73, Mac N8TT
P.S. Obviously, if the question were posed in law school, the best answer
would be to show that the "If" is not satisfied. Since the ideal length of
an antenna is not 0.25 WL, the remainder of the issue is moot.
--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Roy Lewallen" wrote in message
...
Reg Edwards wrote:
Just to start an argument,


Things are even duller than usual in Rowley Regis, I see.

why is it that EZNEC shows zero gain for a
vertical antenna in the horizontal plane? Whereas, all your diagrams
show maximum gain along the horizontal.


C'mon Reg, it's only been three months since you last asked this and got
it answered(1). The time before that was four years earlier(2), and
before that multiple times going back at least to 1998(3). At the rate
you're going, you'll be asking it weekly before long. Getting tired of
promoting "TLI"s, grumping at "Gurus" (while carefully excluding
yourself, of course), grousing about Americans, and asking "Who's
Kraus"? C'mon, be original. Surely you can think of a new topic to keep
you awake on those long, boring evenings. I've got an idea -- maybe you
can use your knowledge to actually help some of the folks who ask
serious questions on this newsgroup.

For anyone who wants an answer to Reg's perennial question, use
groups.google.com to look up the following threads on this newsgroup,
where Reg has asked the same question and where it's been answered:

(1) "best HF antenna system next to a trailer?", Sept. 2005
(2) "40M Delta Loop Advice Needed:", May 2001
(3) "Raised V's burried ground systems." [sic], Feb. 2000
"Ground Radial system comparisons", April 1999
"Is there", Aug. 1998
"Better for DXing: Beam or vertical?", Aug. 1998

Roy Lewallen, W7EL



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