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Bruce in Alaska
 
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In article ,
renewontime dot com wrote:

The metal mast and rigging may not obscure your radar display
(an empty "shadow area"), but some of that energy will be bounced right
back and can either cause interference or even damage to your radar's
receiver. All the more reason not to use a 4 kw system.


Nope, not even close to being true. The radar receiver has a Range Gate
built into the frontend that does not enable the receiver to see
anything untill after the transmitted pulse has long since left the
antenna. The Range Gate timing is what sets the Minimum Radar Range
of the radar and is usually set so that the minimum range is on the
order of 50 or 75 yards. Any reflected Transmitter Pulse will have long
since traveled out to the mast or reflective surface aboard the same
vessel and returned long before the Range Gate opened up the receiver
frontend, looking for a return signal.
Your thinking of the Second Generation Radars with RadioActive TR Cells,
that when hear the end of their useful life just opened up and allowed
the Transmitter Pulse to reach the Microwave Diode Crystals, and destroy
them. All third generation and later radars, use a different Range Gate
System, and are not subject to this type of problem. Any return signal
from farther than 75 yards will be so attenuated in power density, that
it can't hurt the receiver frontend. Inverse Square Law prevails in the
RF World. Now the above is all well and good, but does not take in to
account that when rafted up to another vessel which is operating it's
Radar and your radar is operating as well, and the two antenna's point
exactly at each other for a few cycles of their transmitters, that
damage couldn't happen to the recivers from the others transmitter.
the probubility of this is low, but still significant. Never allow
a rafted vessel to operate a radar, when your antenna is pointed toward
theirs.


Bruce in alaska
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