Hi Yuri,

As Mac said, there are many "its" in the quote. However the vague
combinations do not resolve to different interpretations as you
persist. The extra wire leads to the same conclusion you BOTH
describe and that is Beverage-like antenna characteristics. As that
is a unique consequence of ground's retarding the wavefront, it
necessarily follows that Tom maintains (and directly states) that the
extra wire does NOT interfere with that action. He states why - tight
coupling. He no where states that metallic copper assumes ohmic loss
as the loss is a consequence of proximity to earth. Further, I've
seen no statement from you or Tom that maintains the extra wire
destroys the Beverage-like antenna characteristic, hence there is not
a hair's width difference between you two.

73's
Richard Clark, KB7QHC

First of all, I have not done experiments to compare single wire Beverages vs.
dual wire, with the other wire being laid underneath the Beverage.
I had the problem with statement "the wire below the Beverage is the wire
couples to the lossy media below it so well it becomes very
lossy" as far as I know wire maintains it's conductivity regardless where it is
laid. Perhaps more accurate statement would be that wire laying on the ground
becomes less significant in its contribution to the performance of the above
Beverage.
But because the "ground" wire is connected typically at the termination point
and at the feedpoint to the Beverage system, I am not sure that it can be
"ignored". Some claim this forms the "open wire" parallel system and has
significant effect on the Beverage performance. There is dispute as far signal
arrival angles are concerned, some signals get subjected to wave tilt due to
poor ground, some signals have their own tilt due to propagation and terrain
effects.
To find out the reality, the exact systems should be compared in various
situations. Modeling might not provide fool proof answers due to some programs
having hard time to model reality, that can be confused by varying ground
characteristics along the Beverage.

Yuri, K3BU

"Yuri Blanarovich" wrote in message
...

Hi Yuri,

snipirst of all, I have not done experiments to compare single wire
Beverages vs.
dual wire, with the other wire being laid underneath the Beverage.
I had the problem with statement "the wire below the Beverage is the wire
couples to the lossy media below it so well it becomes very
lossy" as far as I know wire maintains it's conductivity regardless where
it is
laid.

Yuri
Wire conductivity may not be pertinent in this case as "coupling" can reduce
the applied current
I would be extremely surprised if Tom inferred that wire conductivity
changed.
Regards

Art


Perhaps more accurate statement would be that wire laying on the ground
becomes less significant in its contribution to the performance of the
above
Beverage.
But because the "ground" wire is connected typically at the termination
point
and at the feedpoint to the Beverage system, I am not sure that it can be
"ignored". Some claim this forms the "open wire" parallel system and has
significant effect on the Beverage performance. There is dispute as far
signal
arrival angles are concerned, some signals get subjected to wave tilt due
to
poor ground, some signals have their own tilt due to propagation and
terrain
effects.
To find out the reality, the exact systems should be compared in various
situations. Modeling might not provide fool proof answers due to some
programs
having hard time to model reality, that can be confused by varying ground
characteristics along the Beverage.

Yuri, K3BU

On 23 Aug 2004 22:32:00 GMT, oUsama (Yuri Blanarovich)
wrote:
I had the problem with statement "the wire below the Beverage is the wire
couples to the lossy media below it so well it becomes very
lossy" as far as I know wire maintains it's conductivity regardless where it is
laid.

Hi Yuri,

In fact, no one has said otherwise. It follows of common sense unless
ground were exceptionally conductive such that its magnetic field were
to compress the skin-effect layer of the wire. If that were so, it
would be a new world for us all.

Perhaps more accurate statement would be that wire laying on the ground
becomes less significant in its contribution to the performance of the above
Beverage.

Quite so - if demonstrable.

To find out the reality, the exact systems should be compared in various
situations. Modeling might not provide fool proof answers due to some programs
having hard time to model reality, that can be confused by varying ground
characteristics along the Beverage.

C'mon now, with only two or three wires involved? The only problem
modeling programs have difficulty with are with modelers.

I compared two such designs. Nothing very involved with a 3M high
100M long Beverage operating in the 80M band (perhaps not long enough,
I will let others do their best if they find fault). I then compared
it with another which had a wire running below it 1cM above ground
level. The two showed more than 8dB difference with the ground wire
model clearly lossier (EZNEC declared at that same 8dB).

Now, I know that such antennas are not designed to be transmit
antennas (and again, perhaps too short to boot); so I will leave that
to others to engage as a receive antenna if they doubt reciprocity (or
I will do that later this eve for them as I often have to).

Yuri, the problem with you arguing Tom's position is that nothing is
said of this glaring difference. It is quite remarkable (or I made
some remarkable mistake or the wire is just too short as I mentioned)
and it DOES denote a dramatic departure from accepted Beverage
characteristics which has been undisclosed as a comment from Tom, if
in fact he offered it. This 8dB loss does make sense in that you have
a leaky transmission line in a death embrace with ground. The wires
would split the power and the lower power contribution would certainly
attempt to warm the worms with more gusto.
[ IF perhaps we were to employ the old twinlead twist every foot or
so, we might find things evened out ;-) ]

I will let that simmer for this evening.

73's
Richard Clark, KB7QHC

Yuri, the problem with you arguing Tom's position is that nothing is
said of this glaring difference. It is quite remarkable (or I made
some remarkable mistake or the wire is just too short as I mentioned)
and it DOES denote a dramatic departure from accepted Beverage
characteristics which has been undisclosed as a comment from Tom, if
in fact he offered it. This 8dB loss does make sense in that you have
a leaky transmission line in a death embrace with ground. The wires
would split the power and the lower power contribution would certainly
attempt to warm the worms with more gusto.
[ IF perhaps we were to employ the old twinlead twist every foot or
so, we might find things evened out ;-) ]

I will let that simmer for this evening.

73's
Richard Clark, KB7QHC


Here is the perhaps the best outline of the "problem" by VE7DXR and you might
want to try to plug it into program to see the correlation.
Yuri

Observations done here 8 and 15 years ago using a 600m Beverage on the MW
broadcast band seem to verify the above statement. Even though the DC
resistance of the wire is naturally very low, it was found that the
"counterpoise" lying on the ground underneath the antenna, and connecting the
ground rod at the far end of the Beverage with the ground rod at the receiver
end's matching transformer, in fact, was acting like a "Beverage on Ground",
rather than a short circuit between ground rods. That is, it delivered a signal
to the grounded side of the matching transformer. The result was that signal
strengths often were stronger from transmitters broadside to the antenna (10 dB
or so), the occasional solid nulls on signals from the back of the antenna were
degraded, and little increase in signal strength from signals from the far end
of the antenna were observed.

Those of us who performed this experiment stopped using "counterpoises" from
that point forward, unless we used them as antennas in their own right.
best wishes,
Nick, VE7DXR

On 24 Aug 2004 12:45:35 GMT, oUsama (Yuri Blanarovich)
wrote:

Here is the perhaps the best outline of the "problem" by VE7DXR and you might
want to try to plug it into program to see the correlation.

Hi Yuri,

I don't see how. On the face of it, it doesn't make sense.

it delivered a signal to the grounded side of the matching transformer.

It is all fine and well to observe that a wire draped along the ground
picks up signal (such an antenna I have seen "named" the Snake in the
Grass Antenna which is more an open terminated coax). However to
proudly state that it delivers it to ground begs the obvious comment
"how do you know?"

You must in fact break the connection, insert a load, and this means
it no longer delivers it to ground (can't have your cake and eat it
too). Such receive antennas are admittedly poor in efficiency but
useful as "quiet" antennas (where the receiver gain makes up for low
efficiency).

To cap it off, what is the "problem" anyway?

73's
Richard Clark, KB7QHC

On Tue, 24 Aug 2004 00:54:10 GMT, Richard Clark
wrote:

Now, I know that such antennas are not designed to be transmit
antennas (and again, perhaps too short to boot); so I will leave that
to others to engage as a receive antenna if they doubt reciprocity (or
I will do that later this eve for them as I often have to).


Hi All,

I've repeated the models with longer runs: 1000 meters length @ 80M.

For transmits, the single wire over ground shows a gain of 0.42dBi at
10° but with a F/B of 16.4dB. EZNEC proclaims the model exhibits 17dB
loss.

For transmits, the double wire over ground shows a gain of 1.2dBi at
10° but with a F/B of 11.7dB. EZNEC proclaims the model exhibits 17dB
loss.

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).

By this point, what with all the trolling going on and so little
actual technical content, What was this all about?

73's
Richard Clark, KB7QHC

"Richard Clark" asked -

Does reciprocity hold?

-------------------------------------------

How dare you question it?
----
Punchinello.

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

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

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