On Mon, 21 Jan 2008 16:48:25 +0000, larry wrote in
:

John Navas wrote in
:

Marine radars have a limited vertical beam width, and the transponder
should be mounted above or below that vertical pattern. See the
Handbook:

WRONG! Geez, John....

Marine radars have limited HORIZONTAL beamwidth so you can see 3 targets
kinda close together as 3 targets, not 1 blob. They have WIDE VERTICAL
beamwidth so they are pointing at the horizon EVEN WHEN THE BOAT IS HEELED
OVER OR ROLLING!

If they had narrow vertical beamwidth, the only time you'd see the target
is in flat water or at the marina dock!

Read the Handbook. 30° is actually greater than many units.
Garmin GMR 18 HD and GMR 24 HD are 25°. Likewise Furuno and Lowrance,
etc. Check the specs if you still don't believe me.
Many marine radars are gimbal mounted to address the heeling issue.

--
Best regards,
John Navas http:/navasgroup.com