Thread: range of VHF
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Bruce in Alaska Bruce  in Alaska is offline
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First recorded activity by BoatBanter: Jul 2006
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Default range of VHF

In article ,
Larry wrote:

Chuck wrote in news:1181052689_15255
@sp12lax.superfeed.net:

Antenna heights are insufficient for
reliable communication over that
distance. The combined antenna heights
would need to be more than 400 feet for
marginal line-of-sight communication.



I agree with Chuck. Marine radio is useless over-the-horizon more than
5% of optical line-of-sight.

Contact your local 2-way radio shop and ask them about installing TRUNK
RADIOS in both the shore installation and on the boat. The trunk radio
systems use very-high-up digital repeater stations that are widely
interconnected by computers that talk to the trunk radios, not unlike
what a Nextel iDen phone does, but on a much more powerful scale. These
trunk radio systems are shared by many diverse users, who rent service on
them for a pittance of what the entire trunk radio system costs.

Look in your local phone book under "2-way radio" or "trunk radio
systems" or "radio communications".

Professional communications, especially where life and limb might be in
danger, is well worth paying for. It's why the cops all use trunk radio
systems!

Larry


Ok, another Note here, from years of Parctical Experiencein the North
Pacific, 50 Statute Miles VHF Range is very common between Commerical
Shipping, WHERE the antennas are mounted on the TOP of the Masts, and
about 75 to 100 Feet above the water. Comms with HIghSite USCG Stations
that are in the 3000 Ft Range, above SeaLevel, are routinely carried out
out to 90 Statute Miles from these Commercial Ships. In the Bering Sea
it is very typical for the Crab Feet (Deadliest Catch type vessels)
to have good VHF Comms in the 30 to 45 Statute Mile range, and
significantly farther is they both are on TOP of the 30Ft Seas
that typically run in the winter storms. I have Installed, Licensed,and
Inspected, both Public and Private Coast Station, that have typical
30 to 45 Statute Mile coverage, to typical Fishing Fleet (less than 200
Tons) Vessels where the Coast Station Antennas are at the 75 to 100Ft
above Sealevel and the Vessel Antennas are in the 30 to 45 Ft level
range. In the US, VHF Limited Coast Stations are allowed 50 Watts
Carrier Power AT the Antenna Terminal, which allows for higher powers at
the Radio to make up for Feedline Losses. A good OmniDirectional High
Gain VHF Antenna (Cellwave/Phelps Dodge Super Station Master) at the
end of a 150ft run of 7/8" Heliax, with Beldon 9913 Jumpers, is about
the best that can be done for a Limited Coast Station. It makes sense
to put it (the coast Station) on the closest Hill, to the Coast, as
possible for whatever elevation gain you can get, without sacraficing
you limited range to Sea.

Beyound that you loking at SSB, or in the modern era, a TracPhone or
similar. These are going to cost you $2k to 3K by the tme you get them
installed and provisioned.

Bruce in alaska
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