Hi,

Thank you all for the very good suggestions and comments re my previous post
on trying an antenna for receiving Maritime conversations from myt location
of around 20 miles west of Boston harbor.
Really good info. I've copied my old post below, for reference.

Think I would like to try a "dedicated" antenna.

I'm in my 70's now, and frankly, even building a really simple antenna is
probably beyond me. So, I would like to purchase a suitable one, for,
perhaps, $75 or so, max.

For a variety of reasons, would have to go in attic.

Would want it to be very directional, with "lots" of gain, and essentially
tuned for the Maritime freq's of around 155 -170 MHz, receiving only usage.

And, I guess, not too big, so it would fit reasonably in my attic.

If anyone could suggest a "good" commercial unit, would be most
appreciative.

BTW: would it be possible to parallel the coax feed from this new antenna,
with my existing broadband scanner Scantenna antenna (via a "splitter",
or...?), or would phase differences, etc., louse everything up ?

Realize it would undoubtedly be better to use separate coax feeds, but was
wondering about the practicality of using a single feed from the attic ?
(again, receiving only)

Thanks,
Bob
-------------------------------
I have a Uniden 996 scanner and would really like to pick up some marine
traffic from Boston Harbor.
Live about 20 miles due west of the harbor.

Have a Scantenna antenna which I think is "pretty good". It's up in my
attic.

It's omni directional, and broadband over the typical scanner ranges
(supposedly).

I can often pick up coast guard conversations, but very rarely (but
ooccassionally) ship traffic.

Do you think a dedicated, very directional, and tuned to the marine freq's
would help, or am I just too far away ?

Any thoughts on, or antenna suggestions would be most appreciated.
No idea what to buy, if you feel it's worth a try ?

Very interested in the AIS data being transmitted by ships at around 162
MHz, as well as general marine stuff.

Hello Robert,

Whether it will be successful, depends heavily on the path profile
between you and the harbor. When there is a (small) hill between you
and the harbor, you will probably not get reliable reception, even
with a moderate sized directional antenna. Also increasing the height
(to practical values) does not have a large effect (when there are
hills in between).

When the profile is flat (as in most parts of the Netherlands where I
live) it must be possible. However when there are many obstacles
(buildings) close to you (in the direction of the harbor), you also
might increase the height of the antenna (be aware of higher risk of
lightning strikes).

I do not know the "scantenna", maybe some other people can tell us
that. When it is really good, you need a directional antenna to get
improvement. If you want to experiment with antennas, try to arrange
with the vendor that you can bring it back as it doesn't work.
Unfortunately, there is a physical relation between gain of antennas
and size: the more gain, the bigger the antenna.

Other issues
What about the noise floor and interference? Where I live, you cannot
use most scanners without a selective input filter when raising the
antenna.

With respect to using one cable for 2 antennas, yes, theoretically it
can be done, but I don't know whether there are good splitters/filters
in the market for your application.

Best regards,

Wim
PA3DJS
www.tetech.nl

Bob, look at this antenna from Arrow Antennas. They are a good company
with a good reputation among ham radio operators.


http://www.arrowantennas.com/146-4s.html


73 de Jim K4PYT

"Robert11" wrote in message
. ..
Hi,

Thank you all for the very good suggestions and comments re my previous
post on trying an antenna for receiving Maritime conversations from myt
location of around 20 miles west of Boston harbor.
Really good info. I've copied my old post below, for reference.

Think I would like to try a "dedicated" antenna.

I'm in my 70's now, and frankly, even building a really simple antenna is
probably beyond me. So, I would like to purchase a suitable one, for,
perhaps, $75 or so, max.

For a variety of reasons, would have to go in attic.

Would want it to be very directional, with "lots" of gain, and essentially
tuned for the Maritime freq's of around 155 -170 MHz, receiving only
usage.

And, I guess, not too big, so it would fit reasonably in my attic.

If anyone could suggest a "good" commercial unit, would be most
appreciative.


If you have one of those outside TV antennas, you might just try one of
those I'm not sure, but I think they would cover those frequencies - I would
turn it 'sideways' so as to have it vertically polarized.
Use twinlead, and an adapter (4-1 balun).... Then if you discover that
old tv antenna works, then go get a longer one.
(I think they have decent gain, are relatively cheap, and usually have a
good bandwidth - ) (aren't they log-periodic??)

Check out the "Cheap Yagis" site from the Clear Lake Amateur Radio Club in
Texas. They have multi element beam construction projects for the UHF/VHF
bands that could be adapted for Maritime frequencies. They work well, I've
built a 9 el 432 beam that works well. And best of all, they are cheap!

Good luck,

Bill, W4WNT
"Robert11" wrote in message
. ..
Hi,

Thank you all for the very good suggestions and comments re my previous
post on trying an antenna for receiving Maritime conversations from myt
location of around 20 miles west of Boston harbor.
Really good info. I've copied my old post below, for reference.

Think I would like to try a "dedicated" antenna.

I'm in my 70's now, and frankly, even building a really simple antenna is
probably beyond me. So, I would like to purchase a suitable one, for,
perhaps, $75 or so, max.

For a variety of reasons, would have to go in attic.

Would want it to be very directional, with "lots" of gain, and essentially
tuned for the Maritime freq's of around 155 -170 MHz, receiving only
usage.

And, I guess, not too big, so it would fit reasonably in my attic.

If anyone could suggest a "good" commercial unit, would be most
appreciative.

BTW: would it be possible to parallel the coax feed from this new
antenna, with my existing broadband scanner Scantenna antenna (via a
"splitter", or...?), or would phase differences, etc., louse everything
up ?

Realize it would undoubtedly be better to use separate coax feeds, but was
wondering about the practicality of using a single feed from the attic ?
(again, receiving only)

Thanks,
Bob
-------------------------------
I have a Uniden 996 scanner and would really like to pick up some marine
traffic from Boston Harbor.
Live about 20 miles due west of the harbor.

Have a Scantenna antenna which I think is "pretty good". It's up in my
attic.

It's omni directional, and broadband over the typical scanner ranges
(supposedly).

I can often pick up coast guard conversations, but very rarely (but
ooccassionally) ship traffic.

Do you think a dedicated, very directional, and tuned to the marine freq's
would help, or am I just too far away ?

Any thoughts on, or antenna suggestions would be most appreciated.
No idea what to buy, if you feel it's worth a try ?

Very interested in the AIS data being transmitted by ships at around 162
MHz, as well as general marine stuff.