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Jack Painter
 
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Default SSB Antenna connection

"Larry W4CSC" wrote

It isn't very fancy, actually. The Icom AT-140 tuner is screwed to the

top
of the aft cabin just aft of the mizzen mast, which is deck stepped. The
HV RF output post is about 8" from the base of the insulated backstay on
the main and a short, smoothly bent piece of #12 Copperweld antenna wire

is
hose clamped to the Amel's backstay jack out of the way of the winch

handle
socket. The insulator is about a ft from the mast at the top and every
time I look up there I want an insulator on each end of the triatic stay
with an interconnecting Copperweld wire connecting the top of the backstay
antenna to the center of the insulated triatic to make it a capacitor hat
on top of the 50' sloping vertical for the lower frequency bands. If it
ever goes back into the yard for demasting, it will have it...(c; But,

for
now, it just has the backstay.

When Geoffrey got the boat, the previous owner reported poor performance
(he was a ham, too) from the backstay antenna, which I traced down to
loading from the stainless cable topping lift on the large main boom,
sucking off the signal to the mast because when the boom was centered, it
was only a few inches from the backstay. Not good. So, we changed the
stainless to nylon and now no metal gets near the antenna, no matter where
the boom is set. Signal reports came up a LOT!

Directly beneath the tuner, in the support for the deck stepped mast, are
several storage holes I can put wires into. So, I got a #8 battery wire,
black of course, and put a ring terminal to fit the ground post on the
tuner on one end. As straight as I could, I routed it down through the
openings in the mount into the engine compartment which is right under the
mast. Directly under the tuner, too, is the DC shunt used for the ampere-
hour meter on the house batteries under the shunt. This great ground, to
the big 700 AH house batteries against the hull, and the whole house

ground
system, is tied in at the shunt, then the cable drops straight down to the
engine block for more grounding and capacitive coupling through the hull.
Antenna current came way up as did signal reports from this installation.
Dropping a bare Copperweld wire over the side I use for even more

grounding
while underway at sea, I measure only about 1.5 ohms from the bare wire
laying on the bottom of the marina and this ground connection above.
Something's got a great connection to the ocean down there. I musta got
lucky.

That's it. The radio is grounded to a ground strap Amel installed behind
the panel behind the chart table. It's a common ground strap where all my
instrumentation, navigation and communications is tied with small wire.
There is a direct connection between that strap at the nav station and the
engine block and house ground, too. I like to think it may bypass some
static hits, but haven't been through any on this boat....yet. Let's not
rush the testing of this theory.

Larry W4CSC


Sounds great Larry, Thanks. Seen in a Univ of Florida study, paraphrased:

1. All boats can be struck by lightning, protected or not, and
2. Protected boats and unprotected boats both suffer damage when hit, and
3. Unprotected boats suffer significantly more damage than protected boats.

It sounds like you and Lionheart are well protected.

I remember a night of terrible line squalls that wrecked several yachts in
Block Island Salt Harbor. I had stayed up on deck with gear on as I knew it
was coming as I returned from a night on the town. It was worse than any
summer line squall should have been! By the time I roused my family the
winds had the entire harbor dragging anchor. Anyne who has been there can
imagine the panic of watching your Out Island 41 heading toward mega-million
yachts both dragging along with you, and lining the docks for a busy
weekend. The Westerbeke diesel with one anchor could not hold us, and I went
forward to set a second anchor and lots of chain with it. I think there must
have been hundreds of lightning srtikes all around us without any break
between them. Night turned to day, and that helped avoid touching shrouds
while on deck. Everything around us seemed to be getting hit, and of course
it was one of those moments when (at least I) thought I was going to die
from lightning at any moment. But the second anchor and the diesel held us
just short of one of the hundred-footers at the outer docks. In the
aftermath, we heard there was a lot more damage from collisions than from
lightning, and that is amazing considering how many yachts I saw get struck
that night.

Best,

Jack