Has anyone ever tried putting a dipole antenna up with the center insulator
being a high power 50 ohm dummy load,then connecting the dipole elements
across the dummy load.This would always keep a suitable match at 50 ohms
and satisfy the transceiver.Would most of the power go to the dummy load and
not the elements and wouldn't radiate.In thinking about this it all
logically makes sense the load would really never change or would it have
some reactance with the dipole elements.
Thanx All
Howard
VE4ISP

Howard,
Yes. Been some years ago now, but there was even a commercial
version sold (did pretty well too). Wish I could remember the name of
that thingy.
- 'Doc

You're probably thinking of the B&W multi-band folded dipoles.
Very expensive. Great SWR.
--
-larry
K8UT
wrote in message
...
Howard,
Yes. Been some years ago now, but there was even a commercial
version sold (did pretty well too). Wish I could remember the name of
that thingy.
- 'Doc

Doesn't B&W do exactly that?

They called it a "balancing network" or some such thing...a resistor. Army
published a paper on it in the 40's or 50's.

Problem is the loss it causes.


-GC
W2DB


wrote in message
...
Howard,
Yes. Been some years ago now, but there was even a commercial
version sold (did pretty well too). Wish I could remember the name of
that thingy.
- 'Doc

From an offshore site:
http://www.radiohc.org/Distributions/Dxers/ttfd2.html


http://www.hard-core-dx.com/nordicdx...wire/t2fd.html

http://www.universal-radio.com/catalog/sw_ant/0562.html

http://www.johncon.com/john/T2fd/

http://www.wellbrook.uk.com/UMBT2FD.html


http://home.comcast.net/~smithab11/T2FD.htm


http://www.korpi.biz/t2fd.pdf

http://p1k.arrl.org/cgi-bin/topdf.cgi?id=29006&pub=qst (if you have a arrl
membership)







"George Csahanin" wrote in message
...
Doesn't B&W do exactly that?

They called it a "balancing network" or some such thing...a resistor. Army
published a paper on it in the 40's or 50's.

Problem is the loss it causes.


-GC
W2DB


wrote in message
...
Howard,
Yes. Been some years ago now, but there was even a commercial
version sold (did pretty well too). Wish I could remember the name of
that thingy.
- 'Doc

From an offshore site:
http://www.radiohc.org/Distributions/Dxers/ttfd2.html


http://www.hard-core-dx.com/nordicdx...wire/t2fd.html

http://www.universal-radio.com/catalog/sw_ant/0562.html

http://www.johncon.com/john/T2fd/

http://www.wellbrook.uk.com/UMBT2FD.html


http://home.comcast.net/~smithab11/T2FD.htm


http://www.korpi.biz/t2fd.pdf



"George Csahanin" wrote in message
...
Doesn't B&W do exactly that?

They called it a "balancing network" or some such thing...a resistor. Army
published a paper on it in the 40's or 50's.

Problem is the loss it causes.


-GC
W2DB


wrote in message
...
Howard,
Yes. Been some years ago now, but there was even a commercial
version sold (did pretty well too). Wish I could remember the name of
that thingy.
- 'Doc

Howard Kowall wrote:
Has anyone ever tried putting a dipole antenna up with the center insulator
being a high power 50 ohm dummy load,then connecting the dipole elements
across the dummy load.

Yes. There was a commercial antenna quite a few years ago that did just
that. I think QST did a review on it. It wasn't advertised as a resistor
across the end of the coax, but they either tore the thing apart or
X-rayed it, and there it was.


This would always keep a suitable match at 50 ohms
and satisfy the transceiver. Would most of the power go to the dummy load and
not the elements and wouldn't radiate.In thinking about this it all
logically makes sense the load would really never change or would it have
some reactance with the dipole elements.

I guess, But, and hold on to your hat... 50 ohms SWR is not an
indication that an antenna works at all, much less that it works well!

Imagine where the power is going to and what it is becoming. To the
resistor, and it is becoming heat. Anything that is radiated is almost
an accident.

- 73 de Mike N3LI -

"Howard Kowall" wrote in message
...
Has anyone ever tried putting a dipole antenna up with the center
insulator
being a high power 50 ohm dummy load,then connecting the dipole elements
across the dummy load.This would always keep a suitable match at 50 ohms
and satisfy the transceiver.Would most of the power go to the dummy load
and
not the elements and wouldn't radiate.In thinking about this it all
logically makes sense the load would really never change or would it have
some reactance with the dipole elements.
Thanx All
Howard
VE4ISP

It's lossy, but antenna tuners might be too much fiddling.

On Wed, 8 Oct 2008 08:11:04 -0500, Howard Kowall wrote:
Has anyone ever tried putting a dipole antenna up with the center insulator
being a high power 50 ohm dummy load,then connecting the dipole elements
across the dummy load.

This would always keep a suitable match at 50 ohms
and satisfy the transceiver.

You seem to understand nothing about parallel resistances/reactances.

On Wed, 8 Oct 2008 08:11:04 -0500, "Howard Kowall"
wrote:

Has anyone ever tried putting a dipole antenna up with the center insulator
being a high power 50 ohm dummy load,then connecting the dipole elements
across the dummy load.(...)

There was some phony antenna that when tested turned out to be nothing
but a resistor across the feed point. Google search and my fading
memory couldn't recall the name. The VSWR was great, but nothing else
about the antenna was useful, probably due to all your RF power being
dissipated in the 50 ohm load instead of being radiated by the
antenna.

A squashed rhombic with an approximately 500 ohm resistor does have
some proponents. See:
http://www.hard-core-dx.com/nordicdx/antenna/wire/t2fd.html
http://www.hard-core-dx.com/nordicdx/antenna/wire/t2design.html
http://en.wikipedia.org/wiki/T2FD_Antenna
Search Google for "T2FD antenna".


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558