The Furuno is a fairly inexpensive RADAR and yet according to you, it is
doing
nearly impossible things.

Joe,
You are correct, it does, but it's good if it can. 80 nano sec. is quick.
Many of the commercial sets cannot.
Steve

"Commodore Joe Redcloud" wrote in message
...
On Thu, 5 Jan 2006 06:41:49 +0100, "Steve Lusardi"

wrote:

Larry,
You brought up a good point, but your reasoning is incorrect. All marine
scanners have a 30 degree verticle radiation pattern, This is too
compensate
for roll and heel.

Furuno 1623: Vertical beamwidth 25 degrees (12.5 degrees above and 12.5
degrees
below horizontal)

Furuno 1623: Pulse length .08 ms (short), .3 ms (medium), .8 ms (long)

They operate by dumping high voltage on
the cathode, which rings the hell out of the cavity. They turn off when
the
cavity decides it no longer is excited and the receiver can not turn on
until there is no more energy being emitted from the magnetron. This is
becoming a very big issue in Europe at the moment. There now is a new
commercial regulation as of Jan. '06 specifically pointed at canal traffic
that stipulates that all new RADAR sets work at 50 meters. For exactly the
reason you mentioned in your post. Now that's tough to do.
Steve


Furuno 1623: Minimum range 22m




Commodore Joe Redcloud

In article ,
"Steve Lusardi" wrote:

The Furuno is a fairly inexpensive RADAR and yet according to you, it is
doing
nearly impossible things.

Joe,
You are correct, it does, but it's good if it can. 80 nano sec. is quick.
Many of the commercial sets cannot.
Steve

80 nanoseconds isn't all that quick, in Xband, with SolidState Receiver
Frontends, Ring Circulators instead of the old T/R Cells of yesteryear,
and SolidState Modulator Strings instead of the old 2E25 Tube modulators
of yesteryear. Third and fourth generation commerical marine radars, have
been doing this good, for at least 20 years. What many "commercial sets"
can't do, is overcome the cheap design tradeoffs that most OEM's have
made to keep their equipment affordable to the guy who only runs his
yatch once or twice a year. If you pay the price for a good marine
radar, you will get the preformance that your looking for. If not
you will get what the Yatch Club Crowd, thinks they should have to pay.
$5kUS buys a reasonable marine radar, and $10KUS buys you what you
really want, but can't justify to the MRS....... Commercial Operators
buy the later........


Bruce in alaska
--
add a 2 before @