chuck wrote in
ink.net:

Nice boat, but I would not use a deck-mounted whip since it would be
surrounded by metal: not only by the pilothouse, but by the sides as
well! Instead, consider a 16-foot whip mounted on an insulated support
at the level of the gunwhales and supported at the pilothouse roof.
With all the windows in the pilothouse, I wouldn't give losses a
second thought.

Good luck.

Chuck



I'd recommend not putting an HF SSB radio in this little boat at all. Who
are you going to talk to on it? It's not big enough to take to sea for a
cruise, so why would it need SSB capabilities so close to shore?

I doubt you're going to be able to keep an SSB radio working in this wet
environment. WHATEVER you do, don't buy an Icom! Their SSB radios are NOT
sealed up, at all, having many openings that will simply be filled with
spray and destroyed. It isn't going to happen with a radio like M802 or
702 in this boat.

This boat doesn't need SSB. It needs a full-power VHF into a 6 dB folddown
antenna whip.

Well! you've reaped some really good information, and some that is,
shall we say, not quite so helpful. It is obvious that a "lay-down" mount is
a good idea, and it looks like the most practical solution would be a
stainless steel "lay-down" or swivel mount at or near the bottom edge of the
aft window, starboard side, with the upper mount just under, or on the cabin
top overhang. Capacity to ground here is not particularly a plus, but it
looks like it could be ignored.
Don't know if marine SSB or Ham radio (or both) is your aim, but
anywhere outside VHF radio range, there is surely no modestly priced
substitute for marine SSB. The 23 foot whip won't make you the "Voice of the
North Atlantic" on 4125, but it should wake up monitoring stations most
times of the day.
Bruce's notes on licensing are worth listening to, particularly if you
wander up into Canadian waters.
Will we all get to share your first catch for our help?
Old Chief Lynn

"Lynn Coffelt" wrote in news:drm65h$e0g$1
@domitilla.aioe.org:

Don't know if marine SSB or Ham radio (or both) is your aim

I think his money would be much better spent on a GPS-receivered 406 EPIRB
for this little boat's emergency comms, don't you? I don't think he's
gonna be an offshore longliner with outboard motors.

Another good point IS those outboard motors with the heavily-RF-Shielded
plastic covers. I doubt he's gonna HEAR anything but a steady buzz on any
HF frequency with two big 2-strokers using solid wires and straight spark
plugs in all that NOISE!

Thanks again for everyone's input.

To clarify why I am installing a SSB. My boat is a 28' documented vessel with a fisheries endorsement. I fish commercially as much as 100 nm from shore. Any documented commercial fishing vessel operating outside of VHF radio range from shore stations (maybe 25-30 miles on a good day) is required by the Commercial Fishing Vessel Safety Act to carry a MF/HF radio. I have my FCC ship station license and restricted radiotelephone operator permit. I also have a 406 MHz Type 2 EPIRB (also required by law) and other safety devices too numerous to name (also required by law). All I really need to be able to do is contact the nearest shore stations. I'm not looking to talk halfway around the world.

Now back to the installation. I'm leaning toward a guyed installation on the pilot house roof. This will get the antenna up and away from all metal structures. I drew up a sketch of the concept, but I still can't seem to upload any picture files to this server. I'm planning on going with a Shakespeare 5390 17.5' fiberglass coated whip. I'm thinking of attaching three stainless guy wires about 4' up from the base. The idea I have for attaching anchors for the guy wires is to fabricate three aluminum brackets with holes to clip the guy wires to and installing them 120° apart on the antenna whip by wrapping them with fiberglass tape and encapsulating with resin, much the same way that the eyes on fishing rods are attached to the rod blanks. The stainless steel guy wires will attach to three points on the edge of the pilot house roof. My question is will these metal brackets and guy wires cause problems with antenna performance (or roast the occupants of the boat)? The brackets will be electrically isolated from the conductors inside the whip by the fiberglass coating on the whip, but will RF energy still be affected (shunted down through the guy wires to the pilot house)? Does anyone else have any other ideas?

Brad

The shorter whip should hold up better than the long one. It would be
good to determine the frequencies your coast stations will be using and
confirm that your antenna tuner will handle those frequencies with the
17 foot whip.

You don't want to use metal guy wires so close to the antenna. Dacron
would probably be a better choice than stainless for the guys. It also
has some stretch to it. I would think 3/16" braided dacron would be more
than adequate for the purpose. The metal wires could affect antenna
performance, but there's no real danger to people in the pilothouse.
There's another advantage to aluminum! The greater difficulty is that if
you attach the guys at 8 feet up, the angles to the corners of the
pilothouse will be really small, which is not so good. It would be
better at 3-4 feet up, but they guys won't help much if they are that low.

You'll probably get some additional insights as you mount and attempt to
guy the antenna.

If the pilothouse roof is aluminum, you're in good shape. Mount the
tuner close to the base of the antenna and you should be fine.

Good luck!

Chuck

bradleyj wrote:
Thanks again for everyone's input.

To clarify why I am installing a SSB. My boat is a 28' documented
vessel with a fisheries endorsement. I fish commercially as much as
100 nm from shore. Any documented commercial fishing vessel operating
outside of VHF radio range from shore stations (maybe 25-30 miles on a
good day) is required by the Commercial Fishing Vessel Safety Act to
carry a MF/HF radio. I have my FCC ship station license and restricted
radiotelephone operator permit. I also have a 406 MHz Type 2 EPIRB
(also required by law) and other safety devices too numerous to name
(also required by law). All I really need to be able to do is contact
the nearest shore stations. I'm not looking to talk halfway around the
world.

Now back to the installation. I'm leaning toward a guyed installation
on the pilot house roof. This will get the antenna up and away from
all metal structures. I drew up a sketch of the concept, but I still
can't seem to upload any picture files to this server. I'm planning on
going with a Shakespeare 5390 17.5' fiberglass coated whip. I'm
thinking of attaching three stainless guy wires about 4' up from the
base. The idea I have for attaching anchors for the guy wires is to
fabricate three aluminum brackets with holes to clip the guy wires to
and installing them 120° apart on the antenna whip by wrapping them
with fiberglass tape and encapsulating with resin, much the same way
that the eyes on fishing rods are attached to the rod blanks. The
stainless steel guy wires will attach to three points on the edge of
the pilot house roof. My question is will these metal brackets and guy
wires cause problems with antenna performance (or roast the occupants of
the boat)? The brackets will be electrically isolated from the
conductors inside the whip by the fiberglass coating on the whip, but
will RF energy still be affected (shunted down through the guy wires to
the pilot house)? Does anyone else have any other ideas?

Brad

bradleyj wrote in
:

I'm
thinking of attaching three stainless guy wires about 4' up from the
base.

Oops....nope. The guy wires must not become part of the radiator, which
wire will do. The guys should be line, not wire. Use the kind of line
you'd see on a sailboat topping lift and you'll do fine. It's good the
line flexes some as the fiberglass whip is designed to flex some and that
takes the stress off everything.

You can make a 3-point metal plate that will slip over the smaller, upper
part of the whip, but with a hole that won't pass the metal part where it
widens, which I think happens two times on this antenna you're
considering. Slip the whip through the hole and let it seat itself down
the mast with further securing. It isn't going anywhere. The small
metal plate is too small to make any big RF statement on HF. This gives
you a tiepoint for the small supporting, INSULATING, line to tie off to
your cabin roof points. The fold-down mount will then be easy. Release
one line, maybe use a clip on it to tie it to the boat and she'll fold
right over for trailering, which I can see makes my previous fixed
suggestion impossible. Bolt the HF antenna tuner to the top of the cabin
right beside the base so the folding doesn't hit it (port or starboard)
and keep the "hot" lead from the tuner to the antenna as short as
possible.

Be sure to ground the tuner's ground lug to a ring terminal bolted to the
cabin roof, as short as possible, with a heavy strap. Coat the
connections with some grease to keep the water away from them and seal it
up. This ground will make the whole boat the ground counterpoise and
turn the plastic blowboat HF users green with envy for your great ground
plane.

Wouldn't two DIESELS be much cheaper and lots more reliable than outboard
gas guzzlers in a commercial operation???

Wouldn't two DIESELS be much cheaper and lots more reliable than outboard
gas guzzlers in a commercial operation???[/quote]

Yes, diesels would be prefereable. However this hull was specifically designed for twin outboards. It has a transom extension for mounting the outboards. The hull is also pretty shallow, so there's not much space for engines under the deck. As for costs, the outboards were MUCH cheaper to purchase than diesels would have been, especially since I got them used. These are relatively new direct injected, computer controlled 2-strokes and the boat is pretty light (about 5000 lbs dry), so I get great gas mileage; about 2 mpg crusing at 25 knots. What I'd really love would be a pair of 150 HP diesel OUTBOARDS, but I don't think there's any such thing. Having two engines covers me on reliability. I can still make over 25 knots on one motor. Full speed at WOT on both motors is almost 40 knots.

One of the earlier posts mentions RF noise concerns from the motors. Any other opinions on this? I could line the motor cowls with aluminum foil if this would help.

Also, with a 17.5' antenna, at what frequencies would I have best performance at? What kind of ranges could I expect? The only really important frequency for me is 2182 kHz (int'l distress). I need to be able to contact local Coast Guard stations (several of which will be less than 150 miles away at any given time) on this frequency in an emergency.

In article ,
bradleyj wrote:


Thanks agaifor everyone's input.

To clarifwhy I am installing a SSB. My boat is a 28' documented
vessel with
a fisheries endorsement. I fish commercially as much as
100 nm from shore.

snipped for brevity.......

Noback to the installation. I'm leaning toward a guyed installation
on the
pilot house roof. This will get the antenna up and away from
all metal
structures. I drew up a sketch of the concept, but I still
can't seem to
upload any picture files to this server. I'm planning on
going with a
Shakespeare 5390 17.5' fiberglass coated whip. I'm
thinking of attaching
three stainless guy wires about 4' up from the
base. The idea I have for
attaching anchors for the guy wires is to
fabricate three aluminum brackets
with holes to clip the guy wires to
and installing them 120apart on the
antenna whip by wrapping them
with fiberglass tape and encapsulating with
resin, much the same way
that the eyes on fishing rods are attached to the
rod blanks. The
stainless steel guy wires will attach to three points on the
edge of
the pilot house roof. My question is will these metal brackets and
guy
wires cause problems with antenna performance (or roast the occupants of

the boat)? The brackets will be electrically isolated from the
conductors
inside the whip by the fiberglass coating on the whip, but
will RF energy
still be affected (shunted down through the guy wires to
the pilot house)?
Does anyone else have any other ideas?


Ok, now we have just about enough information to make some relativly
speaking, informed observations.
1. A 17.5 Ft unloaded whip isn't going to be much of a radiator in the
MF/HF Marine Radio Bands, below 8 Mhz, no matter what autotuner
you put under it.
2. Just who are you planning to talk to with this MF/HF Radio? Most
of the High Seas Public Corespondence Stations went off the air
a decade ago, so that leaves Private Coast Stations, which may
or may not want to handle your traffic, unless you actually
setup a scheduale with them.
3. You maybe are thinking that the local USCG will actually be
listening to the High Seas Calling Frequencies, and they
actually, may be, but for your operational area, the MF and low
HF Frequencies give the comm's for that area, and your
antenna isn't actually going to preform good enough to allow
resonable expectation of succesful communications.
4. As Larry states, it is a very good thing that you have a 406
EPIRB aboard for Distress Alerting, because if you are depending
on the above MF/HF Radio to save your life, best you get lots
of Life Insurance, and buy a Plot before you go out past VHF
coverage.
5. I suppose you could have a Wx Ballon and Hydrogen Canister aboard
and use that to lift a decent length MF Antenna for Emergency
Communications, but just how well are you going to be able to do
that while in an Emergency Situation.

Yea, Yea I know that the FVSA says you have to fit a MF/HF Radio in order
to be out passed VHF Coverage, in Sea Area A2, but in that area it is
designated that MF comms should be used, and your Antenna System
is going to be more like a Dummy Load, at MF Frequencies than an
antenna.

Bruce in alaska
--
add a 2 before @

bradleyj wrote in
:

These are relatively new direct injected, computer controlled 2-strokes
and the boat is pretty light (about 5000 lbs dry), so I get great gas
mileage; about 2 mpg crusing at 25 knots. What I'd really love would be


Oh, God.....Please tell me they are NOT Ficht engines that you're going to
sea with...Please....

bradleyj wrote in
:

One of the earlier posts mentions RF noise concerns from the motors. Any
other opinions on this? I could line the motor cowls with aluminum foil
if this would help.



If these are Ficht engines, I doubt you'll ever hear anything, foil or not,
on an HF radio. Hell, they wipe out a 5KW AM on 1250 in the harbor! The
computers and that stupid injection system blowtorch eating the heads off
the spark plugs..all those make incredible RF noise. You'd never be able
to shield it all as it sneaks out every wire going to the console, its own
antenna.

Please tell me those are not Ficht engines....How awful.