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Old May 31st 04, 05:45 PM
Jack Painter
 
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"Richard" wrote in message
...
I'm just about getting around to making my 5 or 6 element marine band

yagi,
covering 156 - 162 Mhz RECEIVE ONLY. Do I have to employ a folded dipole

or
can I use just a simple hertz dipole as the "driven" element? I'm trying

to
get away from using a folded dipole if I can. Any wideband designs out

there
that use a simple hertz dipole that I can scale? I'm looking, but if you
have some links aready. TIA.


Richard, I'm sure you have a specific reason for a direcitonal marine
antenna, but just for others who like the sound of that idea... unless all
your marine band traffic is DX from a relatively narrow range of direction,
the beam antennas for marine are more trouble than they are worth in my
experience. I wasted a lot of time spinning the rotator around 359 degrees
with various directional antennas and finally scrapped them all. Even
considering that most beams can hear front and back, more than 10 degrees to
the side(s) and they are deaf by design. A great design popular with amateur
radio and a superb performer on marine-band is the copper pipe J-pole. Tuned
right on center 156.800 Mhz, I have yet to see a vertical hi-gain whip
outperform this setup (probably because factory whips are so far
off-center). I have over 100 miles coverage of USCG high-sites and
approximately 15 miles coverage from on the water small craft with a J-pole.
My antenna is mast-mounted on a 2d story chimney, and in spite of some
erroneous construction advice, it is grounded (well!). The blunt-tip copper
pipe cap on a J-pole is the ultimate lightning rod, and #4 or heavier
conductor to at least an 8' ground rod is highly recommended.

73,
Jack Painter
Virginia Beach, Va