I have a assortment of antenna that I can use for listening .The one
that I get the best Reception on is a 5/8 wave groundplane, feed with
RG-59. I put my MFJ antena analszer on it and and the SWR was nearly
flat all the way across (123 Mhz to 172 Mhz) this year I have things
set up o I can hook two scanners on to the one antena. One thing I
would advise, If you are gonig to cooper in your construction, give it
a coat of trimcald. I ended up doing some high level repairs to my
antena . The groundplane element had a a greenish ttimg to them after
on one year of being exposed to the elemts(weather).

On Mon, 31 May 2004 22:05:17 +0100, "Richard"
wrote:

Whenever I think about a simple VHF wideband omnidirectional vertical
antenna for my marine band listening, I'm always thinking folded dipole. I
think I've got folded dipole on the brain. But wait - isn't it better to
make J-pole. Constructionaly simpler I think, and you can feed with
unbalanced coax. Are J-poles wideband antennas? I want any antenna to cover
156-162 MHZ (6Mhz bandwidth) - RECEICE ONLY. Would a J-Pole do here,
bandwidth-wise?TIA.

I have a assortment of antenna that I can use for listening .The one
that I get the best Reception on is a 5/8 wave groundplane, feed with
RG-59. I put my MFJ antena analszer on it and and the SWR was nearly
flat all the way across (123 Mhz to 172 Mhz) this year I have things

If you have an antenna with a swr that is flat over that large of a
frequency range , you are loosing much of signal in the coax. You can
probably take off the antenna and have about the same swr. If that is your
best antenna, you have much work to do on all your antennas.

"Ralph Mowery" wrote in message
...
I have a assortment of antenna that I can use for listening .The one
that I get the best Reception on is a 5/8 wave groundplane, feed with
RG-59. I put my MFJ antena analszer on it and and the SWR was nearly
flat all the way across (123 Mhz to 172 Mhz) this year I have things

If you have an antenna with a swr that is flat over that large of a
frequency range , you are loosing much of signal in the coax. You can
probably take off the antenna and have about the same swr. If that is
your
best antenna, you have much work to do on all your antennas.

Ralph, that was a pretty funny way of saying that RG-59 is suitable for 3'
test leads only, never for transmission or receiving ;- 0 The
differences realizable with RG-8U or 9913 would be amazing. For anything as
high as high as 225-400mhz, hobbyists split hairs over a 1/2 db, and can
never tolerate a 75ohm dummy load as a feedline. Down around 123 mhz, there
would be slightly less difference. But a coat hanger fed with 9913 might do
as well as a Yagi with RG-59! In order to operate during inclement weather,
I had to add the losses from two connectors (with lightning arrestor) I
didn't have when I used to disconnect and short to the ground bus. That had
a noteable effect on vhf and uhf dx-reception. I have not tested dx-transmit
since that installation.

Jack Painter
Virginia Beach, Va

OK ok
I went back and tested the antena again and heres what I got
138.000 mhz = swr of 2
140.00O mhz = 1.7
142.000 mhz = 1.8
144.000 mhz = 1.5
146.000 mhz = 1.2
148.000 mhz = 1.1
150.00 mhz =1.9
152.00 mhz = 2.5
154.000 mhz = 2.4
156.00 mhz = 2.5
n Wed, 02 Jun 2004 00:29:17 -0700, B Ghostrider
wrote:

I have a assortment of antenna that I can use for listening .The one
that I get the best Reception on is a 5/8 wave groundplane, feed with
RG-59. I put my MFJ antena analszer on it and and the SWR was nearly
flat all the way across (123 Mhz to 172 Mhz) this year I have things
set up o I can hook two scanners on to the one antena. One thing I
would advise, If you are gonig to cooper in your construction, give it
a coat of trimcald. I ended up doing some high level repairs to my
antena . The groundplane element had a a greenish ttimg to them after
on one year of being exposed to the elemts(weather).

On Mon, 31 May 2004 22:05:17 +0100, "Richard"
wrote:

Whenever I think about a simple VHF wideband omnidirectional vertical
antenna for my marine band listening, I'm always thinking folded dipole. I
think I've got folded dipole on the brain. But wait - isn't it better to
make J-pole. Constructionaly simpler I think, and you can feed with
unbalanced coax. Are J-poles wideband antennas? I want any antenna to cover
156-162 MHZ (6Mhz bandwidth) - RECEICE ONLY. Would a J-Pole do here,
bandwidth-wise?TIA.

"B Ghostrider" wrote in message
...
OK ok
I went back and tested the antena again and heres what I got
138.000 mhz = swr of 2
140.00O mhz = 1.7
142.000 mhz = 1.8
144.000 mhz = 1.5
146.000 mhz = 1.2
148.000 mhz = 1.1
150.00 mhz =1.9
152.00 mhz = 2.5
154.000 mhz = 2.4
156.00 mhz = 2.5

HOw many feet of the rg-59 coax is bwtween the antenna and where you
measured the swr ?
With about 75 to 100 feet of coax you will only see about 3:1 with an open
or shorted coax on the far end.

no more than 15 feet
On Fri, 4 Jun 2004 06:23:52 -0400, "Ralph Mowery"
wrote:


"B Ghostrider" wrote in message
.. .
OK ok
I went back and tested the antena again and heres what I got
138.000 mhz = swr of 2
140.00O mhz = 1.7
142.000 mhz = 1.8
144.000 mhz = 1.5
146.000 mhz = 1.2
148.000 mhz = 1.1
150.00 mhz =1.9
152.00 mhz = 2.5
154.000 mhz = 2.4
156.00 mhz = 2.5

HOw many feet of the rg-59 coax is bwtween the antenna and where you
measured the swr ?
With about 75 to 100 feet of coax you will only see about 3:1 with an open
or shorted coax on the far end.