Jpole

Status
Not open for further replies.

steve2004

Member
Joined
May 29, 2006
Messages
77
are Jpole working good?

is the a "blue print" for one
it has to be for 120hmz - 160mhz VHF
 
N

N_Jay

Guest
steve2004 said:
are Jpole working good?

is the a "blue print" for one
it has to be for 120hmz - 160mhz VHF


A J-Pole is NOT a wide band antenna.

There is no good reason to use one over a 40 MHz spread at VHF.

Get a good ground plane or a discone.
 

steve2004

Member
Joined
May 29, 2006
Messages
77
N_Jay said:
A J-Pole is NOT a wide band antenna.

There is no good reason to use one over a 40 MHz spread at VHF.

Get a good ground plane or a discone.


"40 MHz spread at VHF"

I Don't get that one...

I don't a wideband just to cover airplane & 154.xxxx (cops)
simple to build
 

nexus

Member
Joined
Aug 13, 2002
Messages
1,654
Location
Mississippi
steve2004 said:
"40 MHz spread at VHF"

I Don't get that one...

I don't a wideband just to cover airplane & 154.xxxx (cops)
simple to build

Don't worry with the J-Pole... make a 1/4 wave ground plane.

Get you 5 pieces of aluminum or 12gauge solid copper wire, an SO-239 connecter, and 4 bolts and nuts. You'll want to cut 4 of the wires to about 23" long and one at 19" long. The 19" long piece will be the vertical radiator which will be soldered into place on the SO-239. Then the 4 23" pieces will be bolted into the 4 mounting holes of the SO-239. You'll want to bend the 4 wires (ground radials) into a 45 degree angle from the point where they are mounted.

The 45 degree angle will allow the feedline (coax) and the antenna maintain a 50ohm impedance. The longer the radials the lower the frequency it will be tuned for. That range I listed would put you right about the 140-150 mhz range which is a good middle ground to be in if you want to listen to 118-137 and 154-160 mhz.

Then once you have the radials attached to the SO-239 you'll want to find a way to mount it to a pole, usually a piece of plastic or something non-conductive.
 

steve2004

Member
Joined
May 29, 2006
Messages
77
thank you.



nexus said:
Don't worry with the J-Pole... make a 1/4 wave ground plane.

Get you 5 pieces of aluminum or 12gauge solid copper wire, an SO-239 connecter, and 4 bolts and nuts. You'll want to cut 4 of the wires to about 23" long and one at 19" long. The 19" long piece will be the vertical radiator which will be soldered into place on the SO-239. Then the 4 23" pieces will be bolted into the 4 mounting holes of the SO-239. You'll want to bend the 4 wires (ground radials) into a 45 degree angle from the point where they are mounted.

The 45 degree angle will allow the feedline (coax) and the antenna maintain a 50ohm impedance. The longer the radials the lower the frequency it will be tuned for. That range I listed would put you right about the 140-150 mhz range which is a good middle ground to be in if you want to listen to 118-137 and 154-160 mhz.

Then once you have the radials attached to the SO-239 you'll want to find a way to mount it to a pole, usually a piece of plastic or something non-conductive.
 
Status
Not open for further replies.
Top