Larry, nobody's suggesting 9 db antennas. They are for shore stations
and real ships. 6 db, on the other hand, seems to work fine on my 17'
boat. I talk to dive buddies who are theoretically out of range, and
they come in fine, with no fade in/out as the boat rocks.
--
Chuck Tribolet
http://www.almaden.ibm.com/cs/people/triblet
Silicon Valley: STILL the best day job in the world.
"Shortwave Sportfishing" wrote in message ...
On Thu, 01 Jan 2004 16:11:49 GMT, (Larry W4CSC) wrote:
On Wed, 31 Dec 2003 11:30:07 GMT, Jack Burton
wrote:
~~ major snippage ~~
But, if we are talking about adding
this pattern tilting effect to the boat riding down into the trough of
those 30' rollers in a "worst case scenario" where it really counts,
THEN we are talking about disrupted comms. The best antenna for this
situation is NOT the 9dB fiberglass beast mounted on the side of the
helm console.....but the 1/2 wave Metz stainless whip mounted as high
up as you can get it.....with its fat pattern less effected by tilting
that's still sticking up above the waves on top of the sailboat
mast....like a beacon from the lighthouse.
Yes, that is true enough on a sail boat because you are talking about
height in that case which can conquer a multitude of conditions nine
foot antenna or three foot base loaded (end fed) stainless steel.
I'm speaking about a small boat as in, oh say, a 23 foot CC Ranger
with a T-top or a 32 foot Contender with a T-top. I would think that
even in your scenario, the angle of the signal to the horizon when it
leaves the antenna would work the same base load or center fed and
cause signal capture problems at the receiving end regardless.
By the way, neither of those boats would ever be in a situation with
30 foot rollers - if they show up, I'm long gone. :)
FWiW, I have have a 6db 8' Shake Galaxy on my 17' whaler. Works fine
even when it's rock and roll.
"In range" you'll really not see the difference on FM, which signal
strength has less effect on until it's near the fringe.
I just don't like the big, long fiberglass whips on small boats.
Neither does USCG. They got fed up with them breaking off and all use
the Metz, now. Metz brags about it on their webpage.
Interesting - all the USCG small boats around these parts use the
Shakespeare 396-1 which is a center-fed 1/2 wave.
I use one and it's been great antenna.
That's the best antenna mounted as high as you can get it. It's
end-fed by a transformer in that cylinder base. It requires no
groundplane.
How can an antenna work without a ground plane? At the frequencies
we're discussing, the ground effect in FM is about the same as it is
in AM if I understood your discussion points (deleted from this post)
correctly.
I just don't like the way I can't replace the broken
cable permanently mounted to it up inside.....or the screwed-on whip
because I can't slip a 34" piece of coat hanger into the end when the
whip gets busted off by that little pitchpole we did sideways to that
Perfect Strom roller in the night. The Metz whip is mounted in a
gripping ferrule. Coat hanger wire slips right in where the broken
whip comes out.
Wellm to each their own I guess. :)
Later,
Tom
S. Woodstock, CT
----------
"I object to fishing tournaments less for
what they do to fish than what they do to
fishermen." Ted Williams - 1964