SSB Antenna Installation
 

I am going to be installing a 23' whip antenna for a new SSB radio installation on my boat. My vessel is all-aluminum construction with a center pilot house. How would you suggest mounting this antenna on this vessel? I understand that it is important to keep the whip from coming too close to any metal. This is an obvious problem, since this boat is all aluminum. Any suggestions or references would be appreciated.

SSB Antenna Installation
 

You didn't mention how large the vessel is or whether she is power or
sail. I assume she is power the pilot house is on the order of seven
feet above deck.

If you are able to keep the antenna at least two feet from the pilot
house, you shouldn't experience too much signal loss. The proximity of
the pilot house is likely to cause some directivity in the antenna's
radiation pattern, but with two-thirds of the antenna above the pilot
house, it will probably be ok. I have seen cases where the antenna is
insulated to just above the height where it is supported so the antenna
actually starts seven feet above the deck. It is only 16 feet long in
that case but the entire 16 feet would radiate efficiently. Most auto
tuners should handle that on all but the lowest frequencies, and there
are workarounds available.

Your alternatives to the above are to mount the antenna farther from the
pilot house (e.g., at the stern), giving up the support attachment, or
mounting it atop the pilot house (ugh) and guying it. Of course,
depending upon your frequencies of interest, a much shorter whip could
be the solution, maybe obviating the need for guys.

On a calm day, you should be able to do some experimentation before
actually installing the antenna.

Good luck,

Chuck

bradleyj wrote:
I am going to be installing a 23' whip antenna for a new SSB radio
installation on my boat. My vessel is all-aluminum construction with a
center pilot house. How would you suggest mounting this antenna on this
vessel? I understand that it is important to keep the whip from coming
too close to any metal. This is an obvious problem, since this boat is
all aluminum. Any suggestions or references would be appreciated.

SSB Antenna Installation
 

I am going to be installing a 23' whip antenna for a new SSB radio
installation on my boat. My vessel is all-aluminum construction with a
center pilot house. How would you suggest mounting this antenna on this
vessel? I understand that it is important to keep the whip from coming
too close to any metal. This is an obvious problem, since this boat is
all aluminum. Any suggestions or references would be appreciated.

Well, I don't know if you are talking about something like a metal
Morad WH-23 or a fiberglass 23' Shakespeare or equivalent, but both need a
two piece mount. Probably some swivel bottom mount so it can be laid down at
times, and an upper support mount at least two feet up from the bottom.
Placing these two mounts as high as possible on the metal side of the pilot
house is fairly common. If you really want to gain all that length above the
pilot house, a fabricated aluminum tripod or sturdy welded post about three
feet high is cool.
The lead-in from the antenna to the tuner should be almost all outside
the aluminum pilothouse. Lots of boats (and ships) put the tuner outside the
pilothouse, near the antenna base to avoid any lead-in inside the
pilothouse. If you do the latter, very careful attention to sealing of the
coupler, and if you elect to vent it (Usually a plus), be sure the vent hole
is where the manufacturer recommends (at the very bottom, of course).
It would make suggestions a lot easier if you could post a picture or
drawing of your boat.
Tell us when you test so we can listen and report!
Old Chief Lynn

SSB Antenna Installation
 

bradleyj wrote in
:

I understand that it is important to keep the whip from coming
too close to any metal. This is an obvious problem, since this boat is
all aluminum. Any suggestions or references would be appreciated.



You're very lucky, as HF operators go. The metal boat will make an
excellent "ground plane", the counterpoise plastic boat owners dream of.

What kills HF is any PARALLEL metal which the RF waves intercept on their
way out of the boat. This actually creates a capacitor, its two plates
being the mast at boat ground and the whip, with the air as its
insulator, thus shunting the RF energy off to ground. Two feet is not
enough, infinity is. The further you can get the whip away from any
metal rising over it, the better. The best place is atop the mast with
the whip sticking way up above it, but this isn't very practical as
you'll be going under overhead obstructions. So, let's mount the whip as
far away from the mast as we can get, including its guy wires and other
metal/wire/conductive things going aloft.

Let's put the base for the whip on TOP of the nice metal pilot house
ground plane (which ends up perpendicular to the whip). This makes USE
of the excellent ground plane effect of the horizontal pilot house roof,
while keeping the E-field from intersecting it.

PLEASE DO NOT MOUNT THE WHIP ON THE SIDE OF ANY METAL HOUSE if you can at
all help it. The shunt capacitance of the whip near the wall of the
pilot house exterior mounted for convenience on the side somewhere is
just awful...sucking your signal off to that metal along side the whip.
Signals suck like that.

You didn't mention a flybridge atop the pilot house so I'll assume you
don't have one. So, let's mount the whip dead centerline of the pilot
house roof, about a foot from the forward edge of it, with the
weatherproof tuner right next to it. The tuner's output wire to the whip
should be as short as you can possibly make it as that becomes part of
the antenna (and part of the shunt signal off to metal problem).

The ideal mount would be a hole in the pilot house roof with an insulator
mounted THROUGH the roof with the tuner mounted safely INSIDE the pilot
house right next to where the feed-thru mount's "hot" bolt protrudes
inside. Of course, though I'd be proud as hell of it, myself, the
yachties would scowl, seeing the tuner overhead of the pilothouse...(c;

Be sure, wherever you mount the whip/tuner to put a heavy metal stainless
strap from the tuner's ground bolt to the BARE METAL under the closest
leg of the tuner where it's bolted to the pilot house roof, a fantastic
ground.

I'm green with envy. Lionheart has a long strap ground to the engine
block...the only metal mass of any consequence in the plastic ketch....
(sigh).

Larry W4CSC
Lionheart WDB-6254
Icom M802, Icom AT-130, 55' long insulated backstay....poorly
grounded...dammit.

SSB Antenna Installation
 

On Sun, 29 Jan 2006 22:41:06 -0500, Larry wrote:

bradleyj wrote in
:

I understand that it is important to keep the whip from coming
too close to any metal. This is an obvious problem, since this boat is
all aluminum. Any suggestions or references would be appreciated.



You're very lucky, as HF operators go. The metal boat will make an
excellent "ground plane", the counterpoise plastic boat owners dream of.

What kills HF is any PARALLEL metal which the RF waves intercept on their
way out of the boat. This actually creates a capacitor, its two plates
being the mast at boat ground and the whip, with the air as its
insulator, thus shunting the RF energy off to ground. Two feet is not
enough, infinity is. The further you can get the whip away from any
metal rising over it, the better. The best place is atop the mast with
the whip sticking way up above it, but this isn't very practical as
you'll be going under overhead obstructions. So, let's mount the whip as
far away from the mast as we can get, including its guy wires and other
metal/wire/conductive things going aloft.

Let's put the base for the whip on TOP of the nice metal pilot house
ground plane (which ends up perpendicular to the whip). This makes USE
of the excellent ground plane effect of the horizontal pilot house roof,
while keeping the E-field from intersecting it.

PLEASE DO NOT MOUNT THE WHIP ON THE SIDE OF ANY METAL HOUSE if you can at
all help it. The shunt capacitance of the whip near the wall of the
pilot house exterior mounted for convenience on the side somewhere is
just awful...sucking your signal off to that metal along side the whip.
Signals suck like that.

You didn't mention a flybridge atop the pilot house so I'll assume you
don't have one. So, let's mount the whip dead centerline of the pilot
house roof, about a foot from the forward edge of it, with the
weatherproof tuner right next to it. The tuner's output wire to the whip
should be as short as you can possibly make it as that becomes part of
the antenna (and part of the shunt signal off to metal problem).

The ideal mount would be a hole in the pilot house roof with an insulator
mounted THROUGH the roof with the tuner mounted safely INSIDE the pilot
house right next to where the feed-thru mount's "hot" bolt protrudes
inside. Of course, though I'd be proud as hell of it, myself, the
yachties would scowl, seeing the tuner overhead of the pilothouse...(c;

Be sure, wherever you mount the whip/tuner to put a heavy metal stainless
strap from the tuner's ground bolt to the BARE METAL under the closest
leg of the tuner where it's bolted to the pilot house roof, a fantastic
ground.

I'm green with envy. Lionheart has a long strap ground to the engine
block...the only metal mass of any consequence in the plastic ketch....
(sigh).

Larry W4CSC
Lionheart WDB-6254
Icom M802, Icom AT-130, 55' long insulated backstay....poorly
grounded...dammit.

And just how would you recommend supporting that 23 foot whip mounted
on top of the pilot house?

regards
Gary

SSB Antenna Installation
 

Gary Schafer wrote in
:

And just how would you recommend supporting that 23 foot whip mounted
on top of the pilot house?

regards
Gary



Shrouds?....(c;

The discussion was about where to mount the antenna for best radiation.
There are many antennas and mounts that require no cheap little plastic
support like Shakespeare uses on their antennas.

What I'd like to see mounted on top of his pilot house is an antenna like
the Moonraker 18B, with a proper, supportive deck mounting:
http://www.moonraker.com.au/marine.htm#MFHF
Click on 18B for the PDF file. Get the untuned version.

I'd mount this antenna THROUGH the cabin roof so it comes out in the
overhead panel or a cabinet with the tuner mounted out of the weather
inside the pilot house inside the panel. We have no pictures of his
pilot house so we can't see where that might happen. With the tuner
inside the boat, it'd take a direct lightning hit to destroy it, not
seawater. No cables, connectors, wires only the whip would be in the
weather, solving the big corrosion problems completely. This antenna
mount is designed to do just that, feeding the RF through the roof into
the dry tuner inside.

No extra "support" for the bassboat swingdown is necessary....

All this depends on other data we don't have. Where does he go
boating?....Is he going to be going to sea, or is he going up and down
the ditch with all the drawbridges? (If he's not going to sea, there's no
point in HF comms, anyway, so I assume he's going to sea.)....How high is
his mast over the pilothouse?....Does he need a swingdown mount, really,
or are we doing this just because that's the way it's always been done?

We don't have all the data. I was just responding to where the antenna
would be best mounted for best radiation. That's not necessarily the
best for his situation....

Boy, I never expected to get so much great advice so fast!! I'm digesting it all now. I've known since I started looking in to this that I'd have an awesome ground plane, but I never gave much thought to problems I'd have mounting the antenna. I'll let you know how I decide to go. By the way, I tried to post photos of the boat, but this server kept giving me errors. Here's a web site with a pictu

http://www.specmar.com/boatpics/boatpic55.jpg

SSB Antenna Installation
 

Larry makes some good points, although they are couched a little too
heavily in absolutes. I don't agree that the losses with a two-foot
separation would necessarily be unacceptable.

Leaving aside whether the near-field losses will arise from electric
(displacement currents as Larry suggests) or magnetic fields, almost all
metal structures above the deck will alter the near-field properties of
a deck-mounted antenna.

Regarding the sufficiency of a two-foot separation, I would point out
that most HF mobile antennas are mounted well within two feet of the
vehicle's vertical metal components for something like two feet of
vertical rise. There is ample evidence that these installations "work",
or if they do not, it is usually not because of proximity to the
vehicle's vertical surfaces. HF antennas on aircraft have been run
entirely along the metal fuselage with separations on the order of two
feet. These "work" also.

So before rejecting the customary deck-mounting of a 23-foot whip with a
horizontal support, it would be useful to provide the OP with some
concrete indication of how well the antenna is likely to perform
compared to the next best alternative. While I can't do that
quantitatively, (I did suggest an experiment, which a competent tech
could do fairly quickly) it is my experience that such an installation
could be satisfactory.

With only the top 16 feet as a radiator, near-field losses become
negligible but tuner losses predominate. At higher frequencies (above 8
MHz, for example) 16 feet in the clear will probably outperform 23 feet
mounted next to the pilothouse. At lower frequencies it is more
difficult to say which would be better.

Lacking further information from the OP, that is probably the best we
can offer. The antenna, tuner, and SSB manufacturers should be contacted
to mine their experience.

For the strong of heart, center- and/or top-loading could even be
employed in some circumstances to shape the current distribution on the
whip in such a way as to reduce losses near the pilothouse.

Out of curiosity, did the boat's designer/naval architect not address
this design detail? Surely it is not an out-of-the-ordinary design question.

Chuck

Larry wrote:
bradleyj wrote in
:


I understand that it is important to keep the whip from coming
too close to any metal. This is an obvious problem, since this boat is
all aluminum. Any suggestions or references would be appreciated.




You're very lucky, as HF operators go. The metal boat will make an
excellent "ground plane", the counterpoise plastic boat owners dream of.

What kills HF is any PARALLEL metal which the RF waves intercept on their
way out of the boat. This actually creates a capacitor, its two plates
being the mast at boat ground and the whip, with the air as its
insulator, thus shunting the RF energy off to ground. Two feet is not
enough, infinity is. The further you can get the whip away from any
metal rising over it, the better. The best place is atop the mast with
the whip sticking way up above it, but this isn't very practical as
you'll be going under overhead obstructions. So, let's mount the whip as
far away from the mast as we can get, including its guy wires and other
metal/wire/conductive things going aloft.

Let's put the base for the whip on TOP of the nice metal pilot house
ground plane (which ends up perpendicular to the whip). This makes USE
of the excellent ground plane effect of the horizontal pilot house roof,
while keeping the E-field from intersecting it.

PLEASE DO NOT MOUNT THE WHIP ON THE SIDE OF ANY METAL HOUSE if you can at
all help it. The shunt capacitance of the whip near the wall of the
pilot house exterior mounted for convenience on the side somewhere is
just awful...sucking your signal off to that metal along side the whip.
Signals suck like that.

You didn't mention a flybridge atop the pilot house so I'll assume you
don't have one. So, let's mount the whip dead centerline of the pilot
house roof, about a foot from the forward edge of it, with the
weatherproof tuner right next to it. The tuner's output wire to the whip
should be as short as you can possibly make it as that becomes part of
the antenna (and part of the shunt signal off to metal problem).

The ideal mount would be a hole in the pilot house roof with an insulator
mounted THROUGH the roof with the tuner mounted safely INSIDE the pilot
house right next to where the feed-thru mount's "hot" bolt protrudes
inside. Of course, though I'd be proud as hell of it, myself, the
yachties would scowl, seeing the tuner overhead of the pilothouse...(c;

Be sure, wherever you mount the whip/tuner to put a heavy metal stainless
strap from the tuner's ground bolt to the BARE METAL under the closest
leg of the tuner where it's bolted to the pilot house roof, a fantastic
ground.

I'm green with envy. Lionheart has a long strap ground to the engine
block...the only metal mass of any consequence in the plastic ketch....
(sigh).

Larry W4CSC
Lionheart WDB-6254
Icom M802, Icom AT-130, 55' long insulated backstay....poorly
grounded...dammit.

SSB Antenna Installation
 

bradleyj wrote:
Boy, I never expected to get so much great advice so fast!! I'm
digesting it all now. I've known since I started looking in to this
that I'd have an awesome ground plane, but I never gave much thought to
problems I'd have mounting the antenna. I'll let you know how I decide
to go. By the way, I tried to post photos of the boat, but this server
kept giving me errors. Here's a web site with a pictu

http://www.specmar.com/boatpics/boatpic55.jpg


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

SSB Antenna Installation
 

In article ,
"Lynn Coffelt" wrote:

I am going to be installing a 23' whip antenna for a new SSB radio
installation on my boat. My vessel is all-aluminum construction with a
center pilot house. How would you suggest mounting this antenna on this
vessel? I understand that it is important to keep the whip from coming
too close to any metal. This is an obvious problem, since this boat is
all aluminum. Any suggestions or references would be appreciated.

Well, I don't know if you are talking about something like a metal
Morad WH-23 or a fiberglass 23' Shakespeare or equivalent, but both need a
two piece mount. Probably some swivel bottom mount so it can be laid down at
times, and an upper support mount at least two feet up from the bottom.
Placing these two mounts as high as possible on the metal side of the pilot
house is fairly common. If you really want to gain all that length above the
pilot house, a fabricated aluminum tripod or sturdy welded post about three
feet high is cool.
The lead-in from the antenna to the tuner should be almost all outside
the aluminum pilothouse. Lots of boats (and ships) put the tuner outside the
pilothouse, near the antenna base to avoid any lead-in inside the
pilothouse. If you do the latter, very careful attention to sealing of the
coupler, and if you elect to vent it (Usually a plus), be sure the vent hole
is where the manufacturer recommends (at the very bottom, of course).
It would make suggestions a lot easier if you could post a picture or
drawing of your boat.
Tell us when you test so we can listen and report!
Old Chief Lynn



After looking at the Jpeg of the boat in question, I would like to ask
only one question. What would be the purpose of a MF/HF Marine Radio
Installation aboard this vessel? It hardly looks big enough to do any
High Seas operations, but if one could come up with a reasonable answer,
then Old Chief Lynn, makes a good case for the best MF/HF Antenna
installation for this vessel. All the above not withstanding, understand
that any 23Ft unloaded antenna isn't really long enough to provide
quality communications below about 6 Mhz. Also understand that in order
to fit a MF/HF Marine Radio System, you MUST apply for, and be granted,
a Vessel Radio Station License, by the FCC, as this type of radio is
NOT covered by the Blanket Station License granted to all non-commercial
vessels of US flag. All Radio Operators who use this radio, MUST also
apply for, and be Granted, a Restricted Marine Radiotelephone Operators
Permit. (unless you are operating the vessel in alaska)


Bruce in alaska
--
add a 2 before @

SSB Antenna Installation
 

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.

SSB Antenna Installation
 

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

SSB Antenna Installation
 

"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

SSB Antenna Installation
 

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

SSB Antenna Installation
 

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.

SSB Antenna Installation
 

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 @

SSB Antenna Installation
 

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....

SSB Antenna Installation
 

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.

SSB Antenna Installation
 

Bruce in Alaska wrote in news:bruceg-
:

best you get lots
of Life Insurance, and buy a Plot before you go out past VHF
coverage.


ESPECIALLY if those are Ficht engines!

SSB Antenna Installation
 

On Wed, 1 Feb 2006 14:08:56 +0000, bradleyj
wrote:

The only really
important frequency for me is 2182 kHz

Actually not since it is not much used anymore, lots of reasons.

4125 khz is probably your best bet under most conditions. Here is
more information:

http://www.navcen.uscg.gov/marcomms/...ewFreq2005.htm

Regarding engine noise, time will tell. At idle with a good radio and
noise supression circuitry, it may not be that bad. You can get noise
supressed plugs and wires if need be. Alternators can be an issue
also.

Yes everyone, they are Ficht engines. After doing a tremendous amount of research on these motors prior to buying them (including conversations with mechanics who have worked on them), I came to the conclusion that the modifications that OMC made to address the design defects originally present in these motors did the trick. As part of these mods, these particular motors were refitted with redesigned cylinder heads, fuel system modifications and new ECU software. These motors were installed on a NMFS vessel in Alaska for four years. When they repowered their fleet in 2003, I purchased them with about 325 hours on them and put another 100 trouble-free hours on them myself last year. I do the vast majority of my fishing within 20 miles of shore and when I do go offshore, I never go out more than about 100 miles. The chances of both engines failing simultaneously is pretty remote.

If any one of you badmouthing the Fichts has ever owned one and had problems with it I'd like to hear your story. I'll be a bit surprised if anyone can offer anything more than "I know someone who knows someone....". The original design of these motors was definitely deficient and their fix came too late. It contributed substantially to the ruination of OMC, more through the loss of reputation than the quality of their products.

SSB Antenna Installation
 

I am going to be installing a 23' whip antenna for a new SSB radio
installation on my boat. My vessel is all-aluminum construction with a
center pilot house. How would you suggest mounting this antenna on this
vessel? I understand that it is important to keep the whip from coming
too close to any metal. This is an obvious problem, since this boat is
all aluminum. Any suggestions or references would be appreciated.
bradleyj

Ho Boy! Lots of feedback again, here. I would try to keep in mind that
the lower frequencies are what will be useful in attracting USCG and
commercial vessels in the 100 mile range. Not too familiar with East Coast
HF traffic, but here 4125KHZ would be useful. On these lower frequencies the
17' whip isn't likely to perform any thing like the 23' whip you mentioned
earlier. Some auto tuners will be jumping in and out of tune as you transmit
with either the 17' or 23' as your craft rolls and pitches in a stormy sea.
I'd opt for the 23'er for 4125 any day.
Look closely at the lower swivel mount you intend to use..... I'm not
sure there are any stainless swivel mounts on the market that will allow
free movement in more than one plane. If you use non-metallic line (I guess
we're talking synthetic braided rope here) for guy wire/line support,
there's GOING to be movement judging from the size and shape of the vessel
in the picture you posted. REAL MOVEMENT! It will surely make short work of
that lower mount.
As a practical matter, when the seas get snotty, and your engines are
swamped out, you don't need a downed antenna thrashing around the gunnels
after the bottom end of the antenna has suffered a failed mount, or one of
the guys has parted.......... now is when the radio is supposed to earn it's
keep. More than one of my old customers can tell you all about why the SSB
using a well anchored emergency battery is worth all the fish you've got in
the box.
I still think the best compromise, by far, is the old hat system of a
two-piece mount on a vertical surface, metallic or not. You may lose a
percent or two of efficiency, but at least you'll have an antenna. If you
absolutely must use guys, (perish the thought), use good stainless steel
aircraft type cable, available at most larger general hardware stores, and
insulators at the lower end of the cable. "Egg" or "aircraft" in-line
insulators work ok, and they prevent the guy wire/cable from being part of
the ground system. From the looks of your picture, the guys are not going to
be long enough to be any substantial part of a wavelength on the lower HF
bands, so a single insulator at the end nearest the pilothouse overhang
would do it. The "egg" or "aircraft" type insulator, if you are not
familiar, is designed so if the insulator cracks, breaks or disappears, the
two cable or wire ends find themselves looped together and the guy only
gains about an inch or so in length.
Another thought, The Shakespeares (smashed by heavy seas) that I've
seen, have the radiating wires, four, usually, imbedded in the fiberglass
shell fairly near the surface. If you drop a plate over the fiberglass to
attach guys, try to provide something to keep the plate from working around
and wearing through to the radiators not far under the gelcoat.

That's my story, and I'm sticking to it......
Old Chief Lynn

SSB Antenna Installation
 

I was surprised to find your post in this NG, but what the heck. :=)

I have owned and operated a 1998 FICHT since buying it new in 1999. I've
had no parts failures and the only work ever done on the OB was spark plug
replacement and ECU updates.

The engine is quiet, efficient, and clean burning. There is no soot on my
prop hub and the thing never smokes.

There is an interesting thread by FICHT owners on either thehulltruth.com or
boatfix.com forums, sorry I don't remember which.

Butch
"bradleyj" wrote in message
...

Yes everyone, they are Ficht engines. After doing a tremendous amount
of research on these motors prior to buying them (including
conversations with mechanics who have worked on them), I came to the
conclusion that the modifications that OMC made to address the design
defects originally present in these motors did the trick. As part of
these mods, these particular motors were refitted with redesigned
cylinder heads, fuel system modifications and new ECU software. These
motors were installed on a NMFS vessel in Alaska for four years. When
they repowered their fleet in 2003, I purchased them with about 325
hours on them and put another 100 trouble-free hours on them myself
last year. I do the vast majority of my fishing within 20 miles of
shore and when I do go offshore, I never go out more than about 100
miles. The chances of both engines failing simultaneously is pretty
remote.

If any one of you badmouthing the Fichts has ever owned one and had
problems with it I'd like to hear your story. I'll be a bit surprised
if anyone can offer anything more than "I know someone who knows
someone....". The original design of these motors was definitely
deficient and their fix came too late. It contributed substantially to
the ruination of OMC, more through the loss of reputation than the
quality of their products.


--
bradleyj