Thread: Antenna Ratings
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Larry W4CSC
 
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Default Antenna Ratings

On Mon, 29 Dec 2003 03:00:38 GMT, "sk" wrote:

Know anywhere I can find ratings to help decide which antenna?? I have a 23
foot center console. Generally range 10-15 miles offshore and plan to mount
the antenna on my


I don't recommend the very high gain fiberglass antennas for VHF on
small boats that roll so much in swell.

High gain antennas get their high gain from squeezing the vertical
antenna's donut-shaped radiation pattern into one that looks like you
stepped on the donut. As long as the antenna is vertical, this is
fine and steps up the gain very nicely. But, as the antenna is TILTED
in any direction, this flattened-out pattern also tilts,
simultaneously, radiating all that power into the sea on one side and
into the clouds on the other, putting the receiving station in an area
of its radiation pattern that is more of a null, than it would be if
you had used a simpler 1/2 wave vertical whip with the fat donut
pattern. The effect on the signal at the receiver when the super
antenna is rolling around is a signal that's fading in and out as the
high gain pattern plays over the receiving station on its way to
skyward or seaward as the boat rolls.

The best small boat antenna is an end-fed, half wave as high up as you
can mount it. I've used Metz antennas since they started making
home-brew ham antennas in the 70's. Metz antennas have a no-nonsense
LIFETIME warranty! Who could ask for more?
http://www.metzcommunication.com/
I think the Manta 6 is the finest small boat antenna made.
http://www.metzcommunication.com/manta6.htm
It is a simple 1/2 wave, no ground plane, end-fed VHF antenna and will
work anywhere you can put it, plastic, metal, ground or not. The
connector on the bottom of it is the standard SO-239 "CB" connector.
If you break the coil, they'll send you a new one. The whip is fine
stainless steel and the only way you can break it is by FORCE. I have
LOST a couple of them overboard over the years when the little clamp
on top of the coil wasn't tight, though.....

Shakespeare also makes an end-fed halfwave, but it sucks because the
COAX IS PERMANENTLY MOUNTED IN IT so you can't FIX IT when it breaks!
You also can't simply replace a lost whip with a piece of coat hangar
wire, like you can on the Metz, out in the boondocks to get the radio
working again......

Metz has lots of different crazy mounts for it.....