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  #62   Report Post  
Old August 27th 04, 05:00 AM
Tom Donaly
 
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Cecil Moore wrote:
Tom Donaly wrote:

Current waves can travel in two directions at the same time. Charge
can't.



Quoting Kraus: "A coil can also act as a 180 degree phase
shifter ..." Exactly how does a coil act as a 180 degree
phase shifter if charge cannot travel in two directions?
Seems that you also don't comprehend the nature of a
distributed network such as a bugcatcher loading coil.

For a guy who doesn't seem to be able to make the distinction,
you don't have any business criticizing Tom Rauch's understanding of
the situation.



So you believe that charge density is constant throughout
an RF distributed network?
--
73, Cecil http://www.qsl.net/w5dxp



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A charge defined at one point can go one direction or another, Cecil,
as in current, but not two opposing directions at once. And quit telling
me what
I believe; I'll tell you. Let me say in terms you might get this time:
The same infinitesimal charge dQ cannot move in two directions
at the same time. In order to do that it would have to split in two
and that would violate the principle of conservation of charge.
73,
Tom Donaly, KA6RUH
  #63   Report Post  
Old August 27th 04, 05:16 AM
Roy Lewallen
 
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Richard Clark wrote:
. . .
However, Beverages are not typically the first choice for
transmission, but rather reception. Does reciprocity hold? As no one
has offered to help the Little Red Hen, would they care to share in
the cake?

For the receive single wire Beverage @ 10° w/600 Ohm load
Total load power = 5.543E-07 watts

For the receive double wire Beverage @ 10° w/600 Ohm load
Total load power = 6.623E-07 watts

Now, if we compare the two receive loads we find they differ by .77dB
which is the same difference for the transmission models. By most
accounts, that means reciprocity prevails. By further accounts, that
means the double wire system is superior - if you want to lay out 1000
meters of wire for less than one dB (that pesky one dB value judgment
again).
. . .


You wouldn't modify a Beverage or any HF receiving antenna to get more
gain. The whole object is directivity. If you need more gain, turn up
the receiver gain control.

Of course reciprocity prevails. But at HF, the important criteria are
different for transmitting and receiving. When transmitting, it's gain;
when receiving, it's directivity. The Beverage is poor in the first
category but good in the second -- it's a good receiving antenna but a
poor transmitting antenna.

Incidentally, Tom W8JI and I worked out a way some time ago to get
directivity information from EZNEC. You can see an example at
http://www.w8ji.com/receiving_basics.htm in the discussion about Beverages.

Roy Lewallen, W7EL
  #64   Report Post  
Old August 27th 04, 05:27 AM
Richard Clark
 
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On Thu, 26 Aug 2004 21:16:14 -0700, Roy Lewallen
wrote:

Richard Clark wrote:
. . .
However, Beverages are not typically the first choice for
transmission, but rather reception. Does reciprocity hold? As no one
has offered to help the Little Red Hen, would they care to share in
the cake?

For the receive single wire Beverage @ 10° w/600 Ohm load
Total load power = 5.543E-07 watts

For the receive double wire Beverage @ 10° w/600 Ohm load
Total load power = 6.623E-07 watts

Now, if we compare the two receive loads we find they differ by .77dB
which is the same difference for the transmission models. By most
accounts, that means reciprocity prevails. By further accounts, that
means the double wire system is superior - if you want to lay out 1000
meters of wire for less than one dB (that pesky one dB value judgment
again).
. . .


You wouldn't modify a Beverage or any HF receiving antenna to get more
gain. The whole object is directivity. If you need more gain, turn up
the receiver gain control.


If you will note above, there is nothing stated in terms of gain.

Of course reciprocity prevails. But at HF, the important criteria are
different for transmitting and receiving. When transmitting, it's gain;


If you will note in the original posting (the content that has been
edited out here) I do employ the term gain - however only as an
informal comparison.

when receiving, it's directivity. The Beverage is poor in the first
category but good in the second -- it's a good receiving antenna but a
poor transmitting antenna.


That has been attended to several times.

Incidentally, Tom W8JI and I worked out a way some time ago to get
directivity information from EZNEC. You can see an example at
http://www.w8ji.com/receiving_basics.htm in the discussion about Beverages.


Hi Roy,

That's nice. Do you have anything that resolves Yuri's "problem?"
More to the matter, does anyone know what that "problem" is? If it is
merely semantics (as the discussion seems to have evolved into), then
perhaps this matter is more suitable to rec.radio.amateur.linguistics.

73's
Richard Clark, KB7QHC
  #65   Report Post  
Old August 27th 04, 05:32 AM
Yuri Blanarovich
 
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Hi Yuri,

As this is not demonstrated (significantly) through EZNEC in my
models, perhaps you can provide your model that does?

73's
Richard Clark, KB7QHC


I do not have EZNEC model, but you can read up the thread at
http://lists.contesting.com/archives...-08/index.html
and look for 2 wire beverages tec.
Someone tested single wire Beverage and then laid "return" wire underneath on
the ground and noticed deterioration of F/B and higher angle lobes.

Yuri


  #66   Report Post  
Old August 27th 04, 07:18 AM
Richard Clark
 
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On 27 Aug 2004 04:32:16 GMT, oUsama (Yuri Blanarovich)
wrote:

I do not have EZNEC model, but you can read up the thread at
http://lists.contesting.com/archives...-08/index.html
and look for 2 wire beverages tec.
Someone tested single wire Beverage and then laid "return" wire underneath on
the ground and noticed deterioration of F/B and higher angle lobes.

Hi Yuri,

This is like offering an encyclopedia and saying an article about some
famous guy is in there.

Never mind. The data speaks for itself - less than a dB difference.

73's
Richard Clark, KB7QHC
  #67   Report Post  
Old August 27th 04, 09:54 AM
Roy Lewallen
 
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Richard Clark wrote:

Hi Roy,

That's nice. Do you have anything that resolves Yuri's "problem?"
More to the matter, does anyone know what that "problem" is? If it is
merely semantics (as the discussion seems to have evolved into), then
perhaps this matter is more suitable to rec.radio.amateur.linguistics.

73's
Richard Clark, KB7QHC


I've already said all I have to say about Yuri's problems.

Roy Lewallen, W7EL
  #68   Report Post  
Old August 27th 04, 05:11 PM
Richard Harrison
 
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Yuri, K3BU wrote:
"I can see conductor (assuming insulated wire) having its electrical
length affected by the capacitance between wire and earth, but wouldn`t
current stay close to same along the length?"

Depends on distance from the source. Current fades fast close to the
source, but at a great distance, the decline is very slow.

Traveling waves don`t require a complete electrical circuit for
propagation. They travel well in a complete void. So, the volts and amps
far from the wave source don`t need to equal those at the source.

V=frequency times wavelength always prevails. So, capacitance between
wire and earth for a given frequency changes the wavelength because the
velocity of the wave is changed (slowed) by proximity of the earth.

As a traveling wave is free to be attenuated in travel, current must
decline enroute. Brown, Lewis, & Epstein, the 20th Century RCA geniuses,
declared that the place to end extending ground radials is where their
current becomes insignificant.

Yuri also wrote:
"Why do we use radials if the conductors become lossy?"
Yuri also had answered the question before asking. Didn`t Johnny Carson
patent that routine, holding the question envelope to his head while he
gave the answer?
Yuti`s answer: "Wire and dirt, with less resistance wire taking over."

Yuri also wrote:
"Why does the Beverage laid on the ground work?"

Kraus says a wave traveling along a perfect conductor produces an
electric field perpendicular to the conducting surface, but along the
earth the electric field has a forward tilt. The horizontal component of
the vertical wave produced by the tilt is associated with that part of
the wave that enters the surface and is dissipated as heat. The vertical
component of the wave continues to travel along the surface. The emfs
induced along the antenna by the horizontal component made of the tilt,
all add up in the same phase at the receiver. Maximum response is in the
direction of the horizontal wire.

Best regards, Richard Harrison, KB5WZI

  #69   Report Post  
Old August 27th 04, 10:23 PM
 
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Yuri said he would send me a check for the issues I didn't get and he
was true to his word. The check came in the mail today. Thank you
Yuri.

73

Henry WA0GOZ



Yuri Blanarovich wrote:

Can you describe what is on the label, with codes if any please?

Thanks, Yuri


Sure

WA0GOZ S


You are right, I found it on the computer.Printed listings missed it, because I
received your check on 89/06/06 after the regular 8905 issue was mailed, your
payment arrived later, I sent you 8905 issue and it didn't show up on the
printout. Searching computer I found it. I have mailed check with refund today.
I am sorry for mixup, comments and above all, that I was not able to continue
publishing and sinking money into Radiosporting. I am still hoping to scan old
issues and perhaps continue with it on Internet (no money outlay for printing),
but only as time permitting.

I am glad we could sort thing out.

73 Yuri

  #70   Report Post  
Old August 27th 04, 10:59 PM
Yuri Blanarovich
 
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Hi Yuri,

This is like offering an encyclopedia and saying an article about some
famous guy is in there.

Never mind. The data speaks for itself - less than a dB difference.

73's
Richard Clark, KB7QHC


Not really, it is more like saying there is a word or discussion about 2 wire
beverages on page so and so (last few days). Discussion was quite sizable and
worth looking into for those who only play with "soft" antennas and see what
experiences were gained by those who played with real antennas. It was midnight
here and I was closing the shop for the day in anticipation of getting up
early. I had no time to go and do the digest or get into arguments of what IS
is.
Your data speaks of less than one dB, reality is bit different.
But I know, its me (problem), not the software.
Maybe a little less sarcasm would go longer way?

73 Yuri
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