Connect coax shield to pipe when dipole is at top of pipe?
 

I've long used an end-to-end pair of same-band hamsticks on a metal
bracket at the top of a push-up pole for a quick-and-dirty expedient
dipole. My support pole is usually wood, but when I put the dipole
on top of a metal pipe I realized there are two ways to do it:

The hamstick that is connected to the coax center wire
is always insulated from the pole, and the hamstick
that is connected to the coax shield could EITHER be
INSULATED or "GROUNDED" to the pole.

QUESTIONS: Which should it be? Should/Would it make any difference?
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

Connect coax shield to pipe when dipole is at top of pipe?
 

wrote:
I've long used an end-to-end pair of same-band hamsticks on a metal
bracket at the top of a push-up pole for a quick-and-dirty expedient
dipole. My support pole is usually wood, but when I put the dipole
on top of a metal pipe I realized there are two ways to do it:

The hamstick that is connected to the coax center wire
is always insulated from the pole, and the hamstick
that is connected to the coax shield could EITHER be
INSULATED or "GROUNDED" to the pole.

QUESTIONS: Which should it be? Should/Would it make any difference?

I suspect that connecting the shield would be better. Connecting the
shield and using a 1:1 balun at the top would be best.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Connect coax shield to pipe when dipole is at top of pipe?
 

ORIGINAL MESSAGE:

On 23 Dec 2005 20:29:01 -0600, wrote:

The hamstick that is connected to the coax center wire
is always insulated from the pole, and the hamstick
that is connected to the coax shield could EITHER be
INSULATED or "GROUNDED" to the pole.

QUESTIONS: Which should it be? Should/Would it make any difference?
--


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

What would be the point of "grounding" it to the pole? Do you want
some of your RF to flow into the pole and thereby have the pole
radiate? I wouldn't.

The HamSticks are your antenna. Don't add something else unless you
have a specific reason.

The 1:1 balun mentioned by someone else is a good idea. It will keep
all the RF in the antenna and prevent any from flowing on the outside
of the coax. If you choose to not use it, it's not a major deal but
that would distort the antenna pattern a small amount.

73, Bill W6WRT