PHASING HARNESS FOR 2 BAY CIRCULAR POLARIZED ANTENNA?????
 

Good Evening,

I'd like some advice on building the phasing harness
required for the following antenna:

http://members.tripod.com/~AMN92/cp_ant.htm

It certainly would use 75 ohm RG-6, and i
believe it would be 1 full wavelength, fed in the
center, with the two bays on either end (1/2 wave
to each antenna). You would also need 4 turns of
3-4" diameter coils in the RG-6 at the feedpoints,
to serve as baluns, which decouples antenna currents
down the braid.

So in theory, this should be two 100 ohm
impedances in parallel, for a total of 50 ohms,
which can them be fed with garden variety RG-8 or
RG-213.

Any advice or input is greatly appreciated.


Slick

David
Idid describe an antenna that will do all the things that the new patent
claims and
it would not surprise me i9n the least if it turns out to be of the same
design.
I am not a guru so I am not a prisoner to past accomplishments and am able
to focus
purely on max radiation per unit length. Tome the loop is a prime example
in that it produces
not only more gain per unit length but also has an additive vector
radiation in a similar way
centrifugal forces add a vector even tho the electrons
have a constant speed. It does not take a rocket scientist to visualise that
an antenna
with a figure 8 circuit would change the radiation field.( clockwise +
counterclockwise radiation )
The other point to remember is that true coupling can increase the current
in an element
while reducing its voltage and it is current which we hamms are interested
in.
Ofcourse if your radiator melts then it shows good coupling and the element
has to be larger in diameter.
Now I know that what I say is basic but it apears that hams are locked into
a rut when thinking about
new design and if the new patented antenna melted then I suspect he under
estimated the increased
current created by coupling. Now because feed impedance is so important to
the ham it will be important
to have a unconnected vertical placed inside the coil perimeters which
allows by coupling the ability
to meet impedance requirementst
Now David I know hams do not like to pursue the idea of maxcimum radiation
per unit length but
if you have a computor program that can use variable dimensions to meet
specs then I have provided
enough info for those that are interested but I suspect that most are
inately lazy and prefer to0 await the unveiling
at the end of this month. By the way in the description of the multi loop I
made no reference to use of
clockwise and counter clockwise travel a statistic that is very important as
is the center pole.
Am I sold on the idea of a different aproach to antennas, you bet I am as
this aproach provides a
flattening of the take off angle on the horizon at the expense of higher
angle radiation which for cell type frequency
is wasted energy
Cheers and beers
Art

"Dave Platt" wrote in message
...
In article uUdSc.237968$%_6.185742@attbi_s01,
wrote:

Yes, that does seem a reasonable aproach if you want to use the antenna
that
you describe.

It does give me thought about the new revolutionary antenna and the
impact
it will have on radio.

On reading your comments, Art, my feeling is that you've swallowed the
glowing claims in the original press releases hook, line, and sinker,
and as a result you are greatly over-estimating the likely impact of
this "revolutionary" technology.
snip

Dqavid just to clear some things up with reference to "gain"
There is no energy created or destroyed here, all I am doing with this
design is "flattening"
the 3D pattern that you see when you have a vertical whip style antenna.
Thus the radiation can be "pushed"
to augment the usefull existing gain on the horizon whether it
remains purely omni-directional or slightly directional..
I suppose that this can be seen as the various loops in the column have a
redirectiive effect on
high angle radiation emanating from the lower coils,
I'm off to bed
Cheers and beers
Art
" wrote in message
news:XXfSc.241290$IQ4.147543@attbi_s02...
David
Idid describe an antenna that will do all the things that the new patent
claims and
it would not surprise me i9n the least if it turns out to be of the same
snip968$%_6.185742@attbi_s01,
wrote:

Yes, that does seem a reasonable aproach if you want to use the antenna
that
you describe.

It does give me thought about the new revolutionary antenna and the
impact
it will have on radio.

On reading your comments, Art, my feeling is that you've swallowed the
glowing claims in the original press releases hook, line, and sinker,
and as a result you are greatly over-estimating the likely impact of
this "revolutionary" technology.
snip

David I feel sure that the new design is what I have described and we will
know in a few weeks.
But do yourself a favour and roughly model the following
which is not a final design.
Create a closed loop and divide it into 20 segments
and then cut it in half to make the program shorter.
You then place these haf loops at varying heights with a matter of inches
between them. When they are connected
together starting from the ground the resulting patter will be a cloud
warmer with high gain. This does not take long to do and if you scan
frequencies you qill find the pattern change interesting. If you then become
interest then connect the half loops instead of 1,2,3 vertically move the
fthird loop to position one and so forth plus connect them so that you have
both clockwise and counter clockwise
radiation, you will then see a flattening of radiation to the horizon.
Enough said, I am not interested in a verbal snotty battle which will surely
happen now that Richard has entered the thread. If the new patent does not
follow the scheme of things outlined then I will supply to you
a model and a picture of an actual antenna. So let us await the release of
details of this new' revolutionary' antenna which I am sure that Chip will
supply.
Cheers
Art



"Dave Platt" wrote in message
...
In article XXfSc.241290$IQ4.147543@attbi_s02,
wrote:

David

Idid describe an antenna that will do all the things that the new patent
claims and it would not surprise me i9n the least if it turns out to be
of the same
design.

Art,

You've _talked_ about an antenna design which you claim does these
things. You have never, as far as I have seen, "described" it clearly
enough for anyone to actually draw a picture of it that you were
willing to agree was accurate, despite having been asked for this
detail a number of times.

Until you actually demonstrate it (so that it can be subjected to
unbiased tests), or succeed in describing it clearly and accurately
enough that someone else can reproduce it and test the reproduction.

Until you do one or the other, I'm afraid that I have no confidence
that your design does what you say it does, or works the way you say
that it works.

Sorry, guy. On this, I'm "from Missouri"... I say "show me!"

Now David I know hams do not like to pursue the idea of maxcimum
radiation
per unit length but
if you have a computor program that can use variable dimensions to meet
specs then I have provided
enough info for those that are interested

I disagree, Art. Every discussion or description I've seen you write
has been fuzzy, contradictory, unclear, etc.

but I suspect that most are
inately lazy and prefer to0 await the unveiling
at the end of this month.

I don't buy it, Art. I've tried pretty hard to make sense of what
you've written, and have gotten nowhere at all.

By the way in the description of the multi loop I
made no reference to use of
clockwise and counter clockwise travel a statistic that is very important
as
is the center pole.

So, you've "provided enough info for those that are interested" but
have made no reference to two factors that are "very important"?

Am I sold on the idea of a different aproach to antennas, you bet I am as
this aproach provides a
flattening of the take off angle on the horizon at the expense of higher
angle radiation which for cell type frequency
is wasted energy

Fine. Show us.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Wed, 11 Aug 2004 12:32:28 GMT, "
wrote:

I am not interested in a verbal snotty battle which will surely
happen now that Richard has entered the thread.

Hi Art,

I merely pointed out your antenna shows 17dB loss compared to the
standard antenna. Sorry if that rains on your parade.

73's
Richard Clark, KB7QHC

Dr. Slick wrote:
"I`d like some advice on building the phasing harness required for the
following antenna,"

The antenna described has one-wavelength spacing between antenna
elements. As velocity in the coax is only about 2/3 that in free space,
one-wavelength of phase delay in cable won`t stretch between the antenna
bays as shown. Solution is to add another wavelength of phase shift to
the interconnection cable or to simply use a pair of identical cables of
almost any length to parallel the bays at a driving point. Any desired
phase delay can be added to one or the other of the cables to shape the
pattern.

Best regards, Richard Harrison, KB5WZI

Two bays, well above ground, fed in the middle is about as good as can
be done. That is essentially what anonymous said. --- coax to a T and
equal runs from the T to identical elements ---

[Note that using this scheme with identical HF antennas that are not
many WLs above ground, will not optimize performance.]

As pointed out in a recent thread, the ring-and-stub antenna is
sensitive to small changes in dimensions. [very sensitive] If the
antenna is to be designed to be used where it is desired to have the
free-space vertical and horizontal patterns be close to each other (in
the horizontal plane), as in licensed broadcast applications, expect a
lot of tweaking.

On the other hand, if it is not important to "balance" the patterns,
most any balanced feed system will work to produce most of the gain near
the horizontal plane.

Recently, I was faced with the issue of finding an optimum spacing
of such an array from the face of a solid tower with a diameter of about
0.1 wave lengths. No hope, of course, in having the same real world
vertical and horizontal patterns. However, it was possible to find a
spacing that tailored the two patterns to an acceptable degree. The
modeling needed a very large number of segments!

For amateur use, just space the phase center of the most important
part of the antenna the magic 0.3 wave lengths from the tower surface
and point the antenna in the most desired direction. Fortunately,
because the most common amateur use is probably in conjunction with a
repeater, one would be advised to use good old reliable vertical dipoles
as the elements.

In short, in my opinion, you need to have a mighty good reason to
deal with ring-and-stub antennas. For amateur use, better options
exist.

73 Mac N8TT
--
J. Mc Laughlin - Michigan USA
Home:

Jerry Martes wrote:
"Is it clear to you what this array of two CP antennas will be used
for?"

I hope not fo promote terrorism, but I`m not judging the merits of
application nor advising anyone to break the law. I only advised how to
feed the antennas in phase as need be for radiation to be aiding around
the 360-degrees. As for circular polarization, I would refer any reader
to "Antennas" by J.D. Kraus.

Best regards, Richard Harrison, KB5WZI

"Richard Harrison" wrote in message
...
Jerry Martes wrote:
"Is it clear to you what this array of two CP antennas will be used
for?"

I hope not fo promote terrorism, but I`m not judging the merits of
application nor advising anyone to break the law. I only advised how to
feed the antennas in phase as need be for radiation to be aiding around
the 360-degrees. As for circular polarization, I would refer any reader
to "Antennas" by J.D. Kraus.

Best regards, Richard Harrison, KB5WZI

Richard I've been amusing myself by trying to develop an antenna that
"receives" RHCP polar orbiting satellites. The coverage I trying to obtain
would suffer from the stacking refered to in this thread.
And, it seems so obvious that feeding the two antennas in phase would
produce maximum gain on the horizon, that I thought there was some special
requirement for this antenna's pattern.
In addition, I have assumed that the impedance mismatch for receiving
antennas can be allowed to be much greater than for transmitting. This
statement is directed to the fact that transmission line loss is increased
by VSWR, and the reciever isnt restricted to being the same impedance of the
transmission line.

Jerry

"Jerry Martes" wrote in message
...

"Richard Harrison" wrote in message
...
Jerry Martes wrote:
"Is it clear to you what this array of two CP antennas will be used
for?"



snipJerry
I am presently working with circular polarised antennas for transmit,
These antennas are omnidirectional but does produce a choice of TOA
What exactly is the pattern that you are looking for?
I do not have any knoweledge of satellite work needs
Regards
Art

snip