Bruce,
The 20 degree fan does prevent the helmsman on my boat from being in the
path of heavy radiation and the sidelobe power outside that 20 degree fan
is -28 DB and that is important to me. The specs for Furuno radiator
XN20AF/6.5 Beamwidth (H) 1.23 degrees, Beamwidth (V) 20 degrees. On the
other hand their S band antennas are 25 degrees like the SN30AF. In point of
fact all the Furuno X band radars are 20 degrees, not just the 6 footer,
which is in line with your statement that all Slot-Line anennas have the
same vertical fan, but the number is 20 for X Band not 25, but I do recall
that antennas by other manufacturers are 30 degrees.

By the way, I did listen to your advice last year and scrapped the 6 KW
Decca and acquired an FR2125BB.
Steve

"Bruce in alaska" wrote in message
...
In article ,
"Steve Lusardi" wrote:


Ok Steve, Please tell us all about why this would be important.
Actually, the Vertical Beam-width of a ANY Slot-line Radar Antenna, is
NOT related to the length of the Antenna, at all, but IS related to the
design of the Slot-line shielding, and slot-line position inside the
shielding. If you look at the Furuno Antenna Spec's you will notice
that ALL the Slot-Line Antennas, have a 25° Vertical Beam-width, and
have had since Furuno first Started importing their products to the
USA, back in the KRA-121 days.

--
Bruce in alaska
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