On Tue, 25 Nov 2003 21:42:50 -0500, "Jeff Morris"
wrote:

wrote in message
.. .
...
Also, to a lesser extent, you become visible to other shipping in a
way that a horn can't: precisely.


This is a point I've wondered about: it seems that vessels with active radar
appear on my radar with a large arc centered on the vessel's blip. I've assumed
this is an interaction between their radar and mine. Does this also mean that
my radar also enhances my picture on their screen?

-jeff




Don't count on it. The arc that you see from the other guys radar is
from interference from his transmitter. Your radar is picking up your
transmitters echo and his transmitter directly. His pulses are not
synchronized with yours so you see the trail of pulses from his
transmitter while your transmitter is between pulses. It will give
neither of you any indication of where the other is.

This only happens if the two transmitters are very close to the same
frequency. Even though the two radar's may be exactly the same type of
radar, they may or may not be close enough to the same frequency. The
magnetrons are all tuned slightly different and drift somewhat.

On most radar's there is also an interference filter on the receivers
that eliminate or reduce that type of interference.

Then too the other ship may be using a radar in a completely different
band. No interference to either of you.

Regards
Gary