A number of issues have been raised here
that deserve some further comment.

Regarding RF coupling to the standing
rigging, don't be overly concerned. You
will be coupled to the rigging no matter
where you place the antenna. Some
geometries will doubtless be worse than
others, but it will be difficult to
predict in advance. Moreover, such
coupling is not necessarily a bad thing.
It is just a difficult thing to model
and thus more of an unknown.

Regarding antenna length, more is not
necessarily better and may be worse! But
whether worse or better, changing the
length of an antenna may make it
different. For example, if you are
crossing oceans and want reliable skip
communication over great distances, you
want low radiation angles. A
quarter-wave or 5/8-wave vertical will
be your best choice. That would be about
16 feet in length at 14 MHz. Make your
antenna 32 feet long and you have a
half-wave vertical with very little
low-angle radiation at 14 MHz, but at 7
MHz and below, low-angle radiation will
be plentiful.

Which is better depends on your
objectives. Operating near the coast,
you may find that higher radiation
angles produce shorter skip zones to
your advantage.

Were your boat fiberglass or wood
instead of steel, it is possible that a
horizontal antenna laid on the deck
would outperform any vertical antenna
for high radiation angle communications
with a range of say 400 miles. Think
about maintaining solid ssb contact with
boats scattered throughout the Bahamas,
for example. With vertical antennas such
a task would be quite difficult.

Start out your planning with some
consideration of which distances are
most important. From that, move to which
frequencies and radiation angles provide
the appropriate skip zones to achieve
those distances, and from there,
consider antenna options that further
those objectives.

Good luck

Chuck

"Chuck" wrote in message
ink.net...
A number of issues have been raised here that deserve some further comment.

Regarding RF coupling to the standing rigging, don't be overly concerned.
You will be coupled to the rigging no matter where you place the antenna.
Some geometries will doubtless be worse than others, but it will be
difficult to predict in advance. Moreover, such coupling is not
necessarily a bad thing. It is just a difficult thing to model and thus
more of an unknown.

This is my experience.

Regarding antenna length, more is not necessarily better and may be worse!
But whether worse or better, changing the length of an antenna may make it
different. For example, if you are crossing oceans and want reliable skip
communication over great distances, you want low radiation angles. A
quarter-wave or 5/8-wave vertical will be your best choice. That would be
about 16 feet in length at 14 MHz. Make your antenna 32 feet long and you
have a half-wave vertical with very little low-angle radiation at 14 MHz,
but at 7 MHz and below, low-angle radiation will be plentiful.

I think the OP mentioned an automatic tuner. From my experience
both the ICOM and SGC tuners require at least 23'. Not sure how a
longer antenna fairs. Shorter will definitely not tune well.


Good luck

Chuck

In article ,
"Doug Dotson" wrote:

I think the OP mentioned an automatic tuner. From my experience
both the ICOM and SGC tuners require at least 23'. Not sure how a
longer antenna fairs. Shorter will definitely not tune well.

As I posted eslewhere, autotuners have some very specific flaws
that keep them from having optimum preformance. 23' isn't near
long enough for ANY reasonable comm's below 8Mhz. The tuners
get get VERY lossy as input capacitance is increased, in order to tune
short antennas.

Bruce in alaska
--
add a 2 before @

Antennas are really a lot like boats: No
boat will do everything well and no
antenna will either. Boats and antennas
that try to do everything usually fail
across the board.

FWIW, SGC-237, -230, and -231 tuners
need 23 feet only to tune from 1.6 MHz
to 3.3 MHz. Above 3.3 MHz, these SGC
tuners require only eight (8) feet.

The Icom AH-4, for example, needs 23
feet only to tune down to 3.5 MHz, but
will tune from 7 MHz up with Icom's
AH-2b whip (8.2 feet long).

But it doesn't matter what lengths the
tuners require if there is no desire to
operate in that frequency range, and
chances are excellent that recreational
boaters will not be found at the very
low frequencies.

As has been pointed out, some antenna
lengths will be more taxing for an
autotuner than other lengths. Your
objective is not to make life easier for
your tuner, especially when doing so may
move you farther from your real needs.
You may not even need a tuner! Your
objective is to achieve your
communication goals.

You might give some thought to posting
on one of the cruising newsgroups to ask
experienced cruisers for their thoughts
on things like "if you had only one
frequency to operate on, what would it
be? Among other things, that might be
the basis for an antenna you can stow
for emergencies. But tell them where and
how you'll be cruising and what you want
the ssb for (email, emergencies,
boat-to-boat communication, etc.) Then
return to the antenna design questions.

Keep to it!

Chuck

I've been able to do reasonably well on 40 and 80 meters with my
23' whip. I do get more side effects like twinkling lights and sometimes
the LectraSan activates itself

Doug, k3qt
s/v Callista

"Bruce in Alaska" wrote in message
...
In article ,
"Doug Dotson" wrote:

I think the OP mentioned an automatic tuner. From my experience
both the ICOM and SGC tuners require at least 23'. Not sure how a
longer antenna fairs. Shorter will definitely not tune well.

As I posted eslewhere, autotuners have some very specific flaws
that keep them from having optimum preformance. 23' isn't near
long enough for ANY reasonable comm's below 8Mhz. The tuners
get get VERY lossy as input capacitance is increased, in order to tune
short antennas.

Bruce in alaska
--
add a 2 before @

In article . net,
Chuck wrote:

Regarding antenna length, more is not
necessarily better and may be worse! But
whether worse or better, changing the
length of an antenna may make it
different. For example, if you are
crossing oceans and want reliable skip
communication over great distances, you
want low radiation angles. A
quarter-wave or 5/8-wave vertical will
be your best choice. That would be about
16 feet in length at 14 MHz. Make your
antenna 32 feet long and you have a
half-wave vertical with very little
low-angle radiation at 14 MHz, but at 7
MHz and below, low-angle radiation will
be plentiful.

Also be aware that autotuners CAN"T tune antennas that
are within 50Khz of 1/2 wavelength. So inlight of this
one must pick a length of antenna that puts the 1/2
wavelength point on a frequency band that will never be used for
transmitting. Also understand that short antennas preform
very BADLY, as the Input Capacitance on the L tuner model
is increased. So your preformance below 4 Mhz will be drastically
reduced with antennas of less than 50 ft of electrical length.
If your using MF Frequencies for comms of less than 400 miles,
which is what they are there for, you will need a longer
antenna.

Bruce in alaska
--
add a 2 before @

"Bruce in Alaska" wrote in message
...

So your preformance below 4 Mhz will be drastically
reduced with antennas of less than 50 ft of electrical length.
If your using MF Frequencies for comms of less than 400 miles,
which is what they are there for, you will need a longer
antenna.

Bruce in alaska
--
add a 2 before @

Theres been some really good discussion here. In my experiance cruising we
used a whole range of frequencies as sometimes we were communicating with
boats in the same area, and other times with boats back in home port. With
regard to the need for a longer antenna for short range (definatly required)
what are your thoughts on tying the triatic into the backstay as part of the
antenna system (the triatic is 14' long - although as the mizzen is shorter
than the main mast, the angle between the triatic and backstay is only about
30 degrees).

In article ,
"David Swindon" wrote:

"Bruce in Alaska" wrote in message
...

So your preformance below 4 Mhz will be drastically
reduced with antennas of less than 50 ft of electrical length.
If your using MF Frequencies for comms of less than 400 miles,
which is what they are there for, you will need a longer
antenna.

Bruce in alaska
--
add a 2 before @

Theres been some really good discussion here. In my experiance cruising we
used a whole range of frequencies as sometimes we were communicating with
boats in the same area, and other times with boats back in home port. With
regard to the need for a longer antenna for short range (definatly required)
what are your thoughts on tying the triatic into the backstay as part of the
antenna system (the triatic is 14' long - although as the mizzen is shorter
than the main mast, the angle between the triatic and backstay is only about
30 degrees).



Is that the rigging that goes between the mizzenmast and the mainmast
near their tops?

Bruce in alaska
--
add a 2 before @

I've seen quite a few rigged this way. Must be worth something.

Doug
s/v Callista

"David Swindon" wrote in message
...

"Bruce in Alaska" wrote in message
...

So your preformance below 4 Mhz will be drastically
reduced with antennas of less than 50 ft of electrical length.
If your using MF Frequencies for comms of less than 400 miles,
which is what they are there for, you will need a longer
antenna.

Bruce in alaska
--
add a 2 before @

Theres been some really good discussion here. In my experiance cruising we
used a whole range of frequencies as sometimes we were communicating with
boats in the same area, and other times with boats back in home port. With
regard to the need for a longer antenna for short range (definatly
required)
what are your thoughts on tying the triatic into the backstay as part of
the
antenna system (the triatic is 14' long - although as the mizzen is
shorter
than the main mast, the angle between the triatic and backstay is only
about
30 degrees).