On Wed, 20 Jun 2007 11:03:34 -0500, Bob Miller
wrote:

On Sun, 17 Jun 2007 18:56:40 -0400, "Robert11"
wrote:

Hi,

Not very knowledgeable at all re antennas, but let me ask the following,
please.

Would like to try a Yagi for up in my attic to hopefully receive maritime
comms from the harbor, about 20 miles away, on my scanner (receive only
usage).
Presently using a Scantenna, but without much luck.
Probably just a bit too far.

Anyway, i read that a very directional Yagi, with its inherent gain, is
probably worth a try. Willing to do so.

Am not able now at my age to build anything, no matter how simple.

So, I tried to find a Yagi antenna I could purchase for perhaps $ 75 or so,
max.

I looked all over the web, but the only Yagis I could find around the Marine
freq's of
156-163 MHz approx are ones for the 2m bands, which apparently are in the
144 MHz range, and therefore not too suitable for the marine VHF freq's.

Really spent a lot of time looking and searching.

Might anyone know of a suitable Yagi I can consider purchasing for the
marine freq's ?

Much thanks,
Bob


I'm not sure you can buy a yagi beam for the marine band -- a beam
doesn't make much sense in a boat that is traveling in every which
direction. So if home-brewing one is out of the question, you might
look at 2 meter ham band yagi beams -- they'll be within yelling
distance of the marine band.

Good grief.

He's not in a boat, he's at home. He wants to listen to traffic in
the harbor, which I assume isn't moving around either. It's 20 miles
away so the angular separation of any ship traffic moving around in
the harbor will be nill; well within the beamwidth of a Yagi small
enough in his attic.

Someone else has already given him a link to Arrow Antennas, who does
make a marine-band Yagi. A two-meter Yagi that is worth its salt will
be horrible on the marine band.

All of those non-issues aside, to the OP, I would suggest that you
consider instead of a Yagi, that may not work well in the attic
environment, a non-directional ground plane (or even rabbit-ears)
with an antenna-mounted low-noise preamp to overcome transmission line
loss and what is probably lousy noise figure in your scanner.

I've had excellent luck receiving DTV signals over a 40-mile
obstructed path and 100+ miles over a non-obstructed, but over the
horizon path, using a very modest vhf-uhf combo log periodic antenna
and a Channel Master Model 7777 preamp. I got this at Stark

http://www.starkelectronic.com/allamps.htm

Wes N7WS