On Wed, 03 Dec 2003 19:44:00 GMT, Bruce in Alaska
wrote:

In article ,
Rodney Myrvaagnes wrote:

I do see what you describe occasionally with a Raytheon SR 70. I never
have seen the other phenomenon, and I never saw this one with the
previous Furuno 1720.

I don't think it indicates an active radar on the target, because I
have had it happen with big rocks. It usually goes away pretty soon.

What this seems to be is Magnitron Double-Pulsing. This is where,
as the Magnitron ages, and the Modulator Parts age, they get into
a multiple pulse state, and produce a very ragged and multiple peaked
pulse, that shows up as multiple echos in near vacinity of a REAL Target.
The fix for this is, to replace the Magnitron, and the Pulse Forming
Capacitors in the modulator. Not usually found in Noncommercial Marine
Service, because these units typically die of mechanical age, long
before the electronics age out.

I doubt that. This is the new replacement for an ancient Furuno that
never did it.


Well se what "Me" has to say on the subject.


Bruce in alaska




Rodney Myrvaagnes J36 Gjo/a

"That idiot Leibniz, who wants to teach me about the infinitesimally small! Has he therefore forgotten that I am the wife of Frederick I? How can he imagine that I am unacquainted with my own husband?"