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Wet-n-Wild Bill
 
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Default Antenna wire for SSB

I'm planning on installint a 23' whip antenna on my boat with a antenna
tuner. I wondering what wire (size, type and grade) I should use from the
tuner to the antenna (not coax cable)?


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Larry
 
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Default Antenna wire for SSB

"Wet-n-Wild Bill" wrote in
m:

I'm planning on installint a 23' whip antenna on my boat with a
antenna tuner. I wondering what wire (size, type and grade) I should
use from the tuner to the antenna (not coax cable)?



#12-14 is fine, but the most important thing is it should be something
that won't corrode like stainless strap with holes drilled for the
tuner's output terminal. Copper is just eaten.....

The other most important thing lots of installations forget is this strap
is part of the ANTENNA and is NOT a transmission line. It should be as
short as possible and MUST NOT BE AGAINST OR NEAR ANYTHING CONDUCTIVE, or
it will make that object part of the antenna solution. I see this wire
neatly tywrapped to metal rigging to make it pretty all the time. Of
course, then the RF couples through the insulation on the wire and gets
sucked off into the rigging, or a metal box or some neat fitting they put
it through, sucking up the RF energy instead of radiating it. The
energy, unlike AC power, flows AROUND the conductor, not through it,
exactly. It radiates from it, as part of the antenna. So, if you get it
near any wiring, say some cables for other electronics because you're
trying to hide it from view, all those cables will be RF "hot", REALLY
hot at some frequencies where the impedance at the bottom of the whip is
quite high, and can destroy the equipment the cables are hooked to or at
least screw up their electronic operation.

One guy said every time he talked on HF/SSB, his radar reset and the
screen went crazy on his digital display. Further investigation found
the tuner hidden away under the flybridge console to keep it pretty with
the tuner to antenna link wire neatly tywrapped to a cable bundle going
that way. The whole cable bundle was RF "hot" when the transmitter was
on. On receive, of course, he heard every data bit that switched in the
cable...on his HF receiver.

Keep this wire far away from anything and screw the "pretty" if you want
to get a good signal on HF/SSB. The tuners are waterproof, mount it
right under the whip and feed the coax and control cables through the
bulkhead.

And NO TYWRAPPING TO THE HANDRAIL, EITHER!

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Lynn Coffelt
 
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Default Antenna wire for SSB


"Wet-n-Wild Bill" wrote in message
m...
I'm planning on installint a 23' whip antenna on my boat with a antenna
tuner. I wondering what wire (size, type and grade) I should use from the
tuner to the antenna (not coax cable)?

As usual, Larry's tips are worth listening to, but the standard wire
used in these parts is GTO-15. It's high voltage insulation provides
considerable mechanical "stiffness" so it is nearly self-supporting over
short distances. Terminals are usually uninsulated crimp-on "ring" type that
are slightly "wick-in" soldered from the "ring" end only. (after crimping
with the proper tool, of course) Then two or three layers of UV resistant
heat shrink tubing over the wire to terminal joint for a little mechanical
support and water proofing.
There are crimp-on "ring" terminals that have metal two or three times
as thick as the usuall hardware variety, but darned if I can remember just
who makes them. These thicker ones will last a long time.
A couple of coats of painted on "liquid tape" on the completed
connection will help keep the joint dry and corrosion free (ya suure)!
Done carefully, the GTO-15 wire lead will last longer than the 23'
fiberglass antenna.
Good Luck
Old Chief Lynn


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Wet-n-Wild Bill
 
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Default Antenna wire for SSB

Thank for info!

I forgot to mention that the boat is all metal (aluminum). You stated that
the strap should be short! my intent is to place the tuner three to four
feet from the antenna and mount it exposed to the elements on the roof.

Any problems other than Dacron Guywires need when mounting on an aluminum
roof? Also on near by will be other RF cables for Weather Fax and VHF,
where as my GPS and Radar are 14' away!

Bill


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Wet-n-Wild Bill
 
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Default Antenna wire for SSB

Forgot to ask!

The antenna coupler ground wi Since the boat is all aluminum can i use
the cabin's aluminum mounts or must i run a foil to my central ground point?

Bill




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Larry
 
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Default Antenna wire for SSB

"Wet-n-Wild Bill" wrote in
:

I forgot to mention that the boat is all metal (aluminum). You stated
that the strap should be short! my intent is to place the tuner three
to four feet from the antenna and mount it exposed to the elements on
the roof.


That would require the use of standoff insulators to hold the strap, even
insulated wire steadily away from the metal hull. If the wire is
flopping around, moving back and forth near the metal hull, it will
constantly detune then tune then detune the antenna, especially on some
frequencies where the impedance at the bottom of the whip is high. The
tuning solution needs to be fairly stable, so the wire needs to be
stable.


Any problems other than Dacron Guywires need when mounting on an
aluminum roof? Also on near by will be other RF cables for Weather
Fax and VHF, where as my GPS and Radar are 14' away!


Don't let the wire from the tuner to the antenna anywhere near any other
antennas. If it must be near other coaxial cables, these cables need
their shields bonded to the hull as soon as they go inside the boat to
prevent the outside of the coaxial shield from becoming an HF antenna,
leading the transmitter's RF right into the connector on the equipment.
Bonding is simple, out of the weather. Skin off a small ring of the
coax's outer plastic shield, wrap some wire around the outside of the
coax's braided shield, then ground that to the nearest screw into the
metal hull. This will drain off the RF at that point to hull ("ground")
so it doesn't follow the outside of the shield to the equipment the coax
belongs to.

Best would be small plate welded to the hull with coaxial connectors
running through it, those double female through-the-chassis connectors
with females on either end. The coax then uses standard coax connectors
to connect the cut cables to the plate's ground plane. Mine is a 4X8"
stainless plate with two U clamps to an 8' ground rod outside my ham
station. The RF following the cables down from the antenna, bleeds off
to the ground rod on one side. The RF going through the connectors, of
course, is INSIDE the cable and is unaffected. The outside of the coax
going into my house is RF free, now out of the antenna's big field. This
is a bigger issue when you're running 1500 watts PEP SSB...(c; POWER is
our FRIEND.

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