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[aprssig] What a diffeence an antenna makes

Ray McKnight shortsheep at worldnet.att.net
Tue Nov 1 08:44:00 UTC 2005


I too have a great deal of experience with ocean drifters
(WOCE - World Ocean Circulation Experiment).

I have a few questions and comments regarding a potential
buoy deployment.

First, what's the purpose of this?
Sorry, I've not been following the entire thread too closely.

I would strongly discourage deploying a buoy into the Gulf Stream
merely for the thrill and excitement to watch it make it to Europe.
First, it's highly unlikely that many APRS transmissions will ever be
heard - for the most part, the Gulf Stream as too far away for simplex
beacons to be monitored on shore.  You might catch some near southern
FLA and the Outer Banks of NC, but remember most coastal areas are
very low.  An IGATE (or DIGI) generally won't hear very far off shore.

My biggest concern is safe navigation.
We DONT need any more floatsam that can hole and sink
small craft!  Legitimate scientific research is one thing, necessary,
and encouraged.  But doing this merely for a cheap thrill or experiment
isn't IMHO justified. Also, keep in mind that large ships also use
these currents to their advantage, so your bouy is likely to be run
over and sunk.

At a MINIMUM, you should design the buoy with a radar reflector
so at least a small craft has a fighting chance at avoiding it!  You
probably don't yet have a clue how to design it, but rest assured,
it will require a substantial and durable design, no, not necessarily
big, but able to withstand repeated pounding for 1-2 years from
20ft+ waves, sufficient battery (INTERNAL, solar cells are NOT
an option and would certainly be vandalized), UV protection,
and a drogue (if you want to ensure the buoy seeks the current
core and completes its journey).

Most folks put their name/organization on the buoy to aid in
retrieving it, but I suggest that you might avoid this for limiting
your liability in the event your buoy sinks someone!

An ocean drifter isn't generally cheap, nor something built in
your garage over the weekend.  You can expect to spend several
thousand on it.  Is all this worth it, considering that success on
APRS isn't very likely?  Again I ask simply what will be accomplished
by this?

Ray - WB3ABN
Former Mission Commander, International Ice Patrol
Kingston, WA

----- Original Message ----- 
From: "Robert Kirk" <isobar at bcpl.net>
To: "TAPR APRS Mailing List" <aprssig at lists.tapr.org>
Sent: Monday, October 31, 2005 22:04
Subject: Re: [aprssig] What a diffeence an antenna makes


> At 11:15 AM 10/31/05 -0800, Scott Miller wrote:
>
> >[...] A whip antenna would definitely be easiest.  Does anyone know what
> >legal requirements there might be for free-floating buoys?  Like does it
> >need a flag or other markings?
>
> I have a lot of experience with free floating buoys in the open ocean for
> oceanographic research, Legal requirements are pretty much non-existent,
so
> do what you'd like. (Think of unregulated crab pots.)
>
> Also, visibility is a two edged sword. A flag might make it easier for you
> to find & recover,  but it also attracts vandals and souvenir hunters.
> Surprising how many there are, even at sea.
>
> Bob Kirk
> N3OZB
>
>
> _______________________________________________
> aprssig mailing list
> aprssig at lists.tapr.org
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