Mounting J-Pole
 

I have a all copper J-pole antenna. What is the best method to mount it? Can
the bottom piece (below the connector) be connected to a tv mast with clamps?

Randy ka4nma

"Theplanters95" wrote in message
...
I have a all copper J-pole antenna. What is the best method to mount it?
Can
the bottom piece (below the connector) be connected to a tv mast with
clamps?

Yes... you can ground the antenna, in fact,
it is recommended.
__
Steve
KI5YG
..

Gary V. Deutschmann, Sr. wrote:
ospam (Theplanters95) verbositized:


I have a all copper J-pole antenna. What is the best method to mount it? Can
the bottom piece (below the connector) be connected to a tv mast with clamps?


Yes, or stuck right onto the top of the mast!

Or make the bottom piece 4 feet long and attach it to your bumper with a
floor flange. Worked great until that low drive thru :-O

On Wed, 03 Mar 2004 13:48:12 GMT, " Stephen Cowell"
wrote:
[snip]

Yes... you can ground the antenna, in fact,
it is recommended.

There is one problem not often mentioned with connecting a j-pole to a
ground mounted conductive mast. It can increase the amount of higher
angle radiation. Mast lengths that are multiples of ½-wavelengths are
the worst for this problem and mast lengths that are odd multiples of
¼-wave produce the least.

If the mast is not grounded (floating) then the situation is reversed,
½-wave would least high angle radiation and and ¼-wave the most.

NEC modeling has shown that for good low-angle radiation patterns
insulating a j-pole from a conductive mast produces more power towards
the horizon.

73,
Danny, K6MHE

I have a all copper J-pole antenna. What is the best method to mount
it?
Can
the bottom piece (below the connector) be connected to a tv mast with
clamps?

Yes... you can ground the antenna, in fact,
it is recommended.
__
Steve
KI5YG
.

Copper J-pole mast-mounted alongside chimney works extremely well for me on
vhf-marine. Mine is grounded with insulator-supported #4 solid copper wire,
not for antenna performance, but because it more than just resembles an
air-terminal / lightning rod! Because I use heavy feedline, there are no
decouping-loops just under the J-Pole as recommended by most designs. So if
my feedline is radiating, it doesn't seem to hurt the maximun distance I
obtain with that antenna. It works very efficiently far beyond the
theoretical radio horizon.

Jack
Oceana Radio

On Wed, 03 Mar 2004 07:54:25 -0800, Dan Richardson
wrote:

On Wed, 03 Mar 2004 13:48:12 GMT, " Stephen Cowell"
wrote:
[snip]

Yes... you can ground the antenna, in fact,
it is recommended.

There is one problem not often mentioned with connecting a j-pole to a
ground mounted conductive mast. It can increase the amount of higher
angle radiation. Mast lengths that are multiples of ½-wavelengths are
the worst for this problem and mast lengths that are odd multiples of
¼-wave produce the least.

From what I've read, there is practically no RF on the lower crook of
a "J" antenna, so why would using that crook as a mount and/or ground
attachment make much of a difference?

Bob
k5qwg



If the mast is not grounded (floating) then the situation is reversed,
½-wave would least high angle radiation and and ¼-wave the most.

NEC modeling has shown that for good low-angle radiation patterns
insulating a j-pole from a conductive mast produces more power towards
the horizon.

73,
Danny, K6MHE

On Wed, 03 Mar 2004 19:46:16 -0600, Bob Miller
wrote:

From what I've read, there is practically no RF on the lower crook of
a "J" antenna, so why would using that crook as a mount and/or ground
attachment make much of a difference?

There is little RF voltage but there is a very high level of RF
current.

The same situation you find in the center of a ½-wave dipole (low
voltage/ high current).

Danny, K6MHE

gwatts verbositized:

Gary V. Deutschmann, Sr. wrote:
ospam (Theplanters95) verbositized:


I have a all copper J-pole antenna. What is the best method to mount it? Can
the bottom piece (below the connector) be connected to a tv mast with clamps?


Yes, or stuck right onto the top of the mast!

Or make the bottom piece 4 feet long and attach it to your bumper with a
floor flange. Worked great until that low drive thru :-O

Hmmmmmmmmm, I had a multi-band J-Pole mounted to my trunk deck for
years and never had a problem with it. AND it was all copper! Except
for the mounting flange which was brass using brass bolts and nuts.
And on the other side of the trunk I had a home brew Saturn V halo for
6-meters, now talk about something that could rip sheet metal apart,
that was the baby that could do it!
There was NO room on the bumper for anything else, it already had 6
whips chained to it. Looked like a picket fence with a basketball
hoop on it cruising on down the road!

TTUL
Gary