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-   -   Caged Di-Pole (https://www.radiobanter.com/antenna/101573-caged-di-pole.html)

Joe Bloe August 16th 06 10:06 PM

Caged Di-Pole
 
Hello,
My attention has been caught by the abilities of a "Fat Conductor"
for an antenna. I understand that this has been achieved by using
what is (little known about) a Caged Di-Pole. I have seen them before
in older photographs, mostly draped over an old steamship, stem to
stern.

The Caged Di-Pole is supposed to be very well suited for weak signal
reception. I know that a Yagi can do very well in this regard, but
its the art of it that I'm interested in, and as far as I can see,
it's almost an lost aspect of HAM radio nowadays.

Does anybody remember these things?

73's
Rob

lu6etj August 16th 06 11:06 PM

Caged Di-Pole
 
Hi Joe..

The main advantage of cage dipole it is its wider bandwidth.
It is a nice antenna with a great "vintage" look. Apart from this, its
performance is that of a standard dipole...

Best regards

Miguel Ghezzi (LU 6ETJ)


Richard Clark August 16th 06 11:11 PM

Caged Di-Pole
 
On Wed, 16 Aug 2006 14:06:06 -0700, Joe Bloe
wrote:

The Caged Di-Pole is supposed to be very well suited for weak signal
reception.


Hi Rob,

"Supposed to be" is how fairy tales end; they start with "Once upon a
time."

I know that a Yagi can do very well in this regard, but
its the art of it that I'm interested in, and as far as I can see,
it's almost an lost aspect of HAM radio nowadays.

Does anybody remember these things?


More than those who can explain why, when push comes to shove. Hence
your complete introduction should have read:
Once upon a time the Caged Di-Pole was supposed to be very well
suited for weak signal reception.

The only attribute of a (uncommon) cage structure is wider bandwidth
than a (common) thin wire antenna. This is not the same as bringing
more sensitivity. The exertion of building one, and then erecting it
probably induces a wishful sense of dream fulfillment.

73's
Richard Clark, KB7QHC

Reg Edwards August 17th 06 02:39 AM

Caged Di-Pole
 

"Joe Bloe" wrote in message
...
Hello,
My attention has been caught by the abilities of a "Fat Conductor"
for an antenna. I understand that this has been achieved by using
what is (little known about) a Caged Di-Pole. I have seen them

before
in older photographs, mostly draped over an old steamship, stem to
stern.

The Caged Di-Pole is supposed to be very well suited for weak

signal
reception. I know that a Yagi can do very well in this regard, but
its the art of it that I'm interested in, and as far as I can see,
it's almost an lost aspect of HAM radio nowadays.

Does anybody remember these things?

73's
Rob

======================================
Rob,

Photographs of a cage of wires slung between a ship's masts could have
been T-antennas in the good old days of LF spark transmitters. The
fat conductors increased the capacitance to ground so drawing a
greater current into the antenna.

For the electrical characteristics of a caged dipole at HF, download
program DIPCAGE2 from website below.

Yes, the only advantage of a caged dipole is a moderate increase in
bandwidth. Its resonant length is slightly less than that of a thin
wire. Its appearance has the disadvantage of upsetting residential
associations.

A few amateurs, without near neighbours, for seventy-mental reasons
still swear by it!
----
Reg, G4FGQ.



Bob Bob August 17th 06 06:54 AM

Caged Di-Pole
 
Not that it is too relevant to your original post....

Cebik (http://www.cebik.com) talks about using multi conductor elements
in wire quad design to "fatten" the conductor. He mentions that thin
wire designs tend to be somewhat lossy (lower fwd gain and narrower b/w
etc) and the thicker elements make up for this.

Cheers Bob VK2YQA

Joe Bloe wrote:

Hello,
My attention has been caught by the abilities of a "Fat Conductor"


Denny August 17th 06 12:51 PM

Caged Di-Pole
 

Reg Edwards wrote:


A few amateurs, without near neighbours, for seventy-mental reasons
still swear by it!
----
Reg, G4FGQ.


Hey Reg,
It was good enough for Marconi.... I wonder what the locals thought..

denny


Joe Bloe August 18th 06 01:14 AM

Wow. . .
 
Gee. . . You're sure a cheery fellow.
I was mostly interested in the Historic Art of the darn thing. I
well know it's majorly "Out Dated", but if one does things for the
pure enjoyment of it, then I guess it's not the issue of performance,
but art, which is also defined by retrieving a wonderful time from out
of our past. I'm just a stupid romantic at heat. . . And I enjoy
being so.
Thanks for the info though. I guess some how I got the information
backwards, but then again, I also see a great many views on the
subject of a fat conductor. . . Me thinks the subject still isn't
closed due to that simple fact that nobody really yet knows for sure.

73's
Rob



On Wed, 16 Aug 2006 15:11:10 -0700, Richard Clark
wrote:

On Wed, 16 Aug 2006 14:06:06 -0700, Joe Bloe
wrote:

The Caged Di-Pole is supposed to be very well suited for weak signal
reception.


Hi Rob,

"Supposed to be" is how fairy tales end; they start with "Once upon a
time."

I know that a Yagi can do very well in this regard, but
its the art of it that I'm interested in, and as far as I can see,
it's almost an lost aspect of HAM radio nowadays.

Does anybody remember these things?


More than those who can explain why, when push comes to shove. Hence
your complete introduction should have read:
Once upon a time the Caged Di-Pole was supposed to be very well
suited for weak signal reception.

The only attribute of a (uncommon) cage structure is wider bandwidth
than a (common) thin wire antenna. This is not the same as bringing
more sensitivity. The exertion of building one, and then erecting it
probably induces a wishful sense of dream fulfillment.

73's
Richard Clark, KB7QHC


Joe Bloe August 18th 06 01:22 AM

Caged Di-Pole
 
Gee, Wow...
I got a little bit of info, enough to find that what I was told
wasn't quite right after all. Being that I'm a bit new to the antenna
aspect of things, I don't find this surprising at all. However, I did
get a two bits of good information, a closer explanation of the effect
of a fat conductor antenna, and a web-site with a calculator for just
such a thing.

Thanks folks, this query has been a total success due to those who
care. . . You all!

73's
Rob

Cecil Moore August 18th 06 02:02 AM

Caged Di-Pole
 
Joe Bloe wrote:
However, I did
get a two bits of good information, a closer explanation of the effect
of a fat conductor antenna, and a web-site with a calculator for just
such a thing.


You can probably arrive at the same correct technical
conclusions by downloading the free demo version of
EZNEC and selecting the diameter of the conductor.
--
73, Cecil http://www.qsl.net/w5dxp

Mike Coslo August 18th 06 02:33 AM

Caged Di-Pole
 
Cecil Moore wrote:
Joe Bloe wrote:

However, I did
get a two bits of good information, a closer explanation of the effect
of a fat conductor antenna, and a web-site with a calculator for just
such a thing.



You can probably arrive at the same correct technical
conclusions by downloading the free demo version of
EZNEC and selecting the diameter of the conductor.


No doubt, Cecil. Of course this wasn't where the conversation started
at. I haven't tried EZNEC to model a cage antenna, will it do it? Or do
you just make the wires really thick? And how does really thick wire
compare to a cage of the same relative diameter?

- 73 de Mike KB3EIA -


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