TX Distance question
 

Hi Folks

I have limited experience (ok almost none really) with respect to
Amateur Radio outside of the 2M band. However I just recently got my
code ticket & installed a radio on my sailboat. I am using a TS-50 with
an automatic tuner and a long copper wire to the top of the mast
(probably 50 feet or so long).

My ground plane/counterpoise consists of tying the ground to a large
aluminium area in the stern of the boat with a copper foil.

My very first contacts were established with 2 land stations on 14300 at
100W that were about 1000 miles away. They both reported that my signal
was good and that it sounded like I was "sitting right next to them". I
have no idea if this was a good distance, great, or mediocre.

I realize that propogation variables prevent anyone from giving a really
clear answer to this question, but in general, what sort of distance
should I expect to achieve? I'm trying to decide whether I need to
improve my antenna ground by adding a dynaplate (costly and requies the
boat to be taken from the water for installation) or whether the range I
am getting is decent.

Can anyone comment?

Thanks

James wrote:
I have limited experience (ok almost none really) with respect to
Amateur Radio outside of the 2M band. However I just recently got my
code ticket & installed a radio on my sailboat. I am using a TS-50 with
an automatic tuner and a long copper wire to the top of the mast
(probably 50 feet or so long).

My ground plane/counterpoise consists of tying the ground to a large
aluminium area in the stern of the boat with a copper foil.

My very first contacts were established with 2 land stations on 14300 at
100W that were about 1000 miles away. They both reported that my signal
was good and that it sounded like I was "sitting right next to them". I
have no idea if this was a good distance, great, or mediocre.

I realize that propogation variables prevent anyone from giving a really
clear answer to this question, but in general, what sort of distance
should I expect to achieve? I'm trying to decide whether I need to
improve my antenna ground by adding a dynaplate (costly and requies the
boat to be taken from the water for installation) or whether the range I
am getting is decent.

Propagation will have a HUGE effect on your distance capability. Under
good conditions your station should be able to work any point on earth.
On the other hand, when the 14MHz band "goes out" (which at this point
in the sunspot cycle will happen pretty much every night) you'll be
lucky to work 30 miles.

I think the ground you describe should be more than adequate. (many
land-based mobiles settle for something MUCH, MUCH worse!)

You'll need lower frequencies for nighttime operation. 7MHz and 3.5MHz.
The antenna *may* (or may not) be too short for effective operation on
these bands. Try it, the worst that can happen is the automatic tuner
will refuse to make a match. (I think you'll probably be OK on 7, 3.5
may be a problem)

Good luck!
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

"James" wrote
an automatic tuner and a long copper wire to the top of the mast
(probably 50 feet or so long).

My ground plane/counterpoise consists of tying the ground to a large
aluminium area in the stern of the boat with a copper foil.

My very first contacts were established with 2 land stations on 14300 at
100W that were about 1000 miles away. They both reported that my signal
was good and that it sounded like I was "sitting right next to them". I
have no idea if this was a good distance, great, or mediocre.

I realize that propogation variables prevent anyone from giving a really
clear answer to this question, but in general, what sort of distance
should I expect to achieve? I'm trying to decide whether I need to
improve my antenna ground by adding a dynaplate (costly and requies the
boat to be taken from the water for installation) or whether the range I
am getting is decent.

James, considering you most likely have an ungrounded counterpoise instead
of a good ground commonly employed, I think that's outstanding distance from
a sailboat. In many cases during daytime operation, I have heard the Mobile
Maritime Nets have to shift around to various operators before they could
have copy as good as you describe, and from a lot less distance. If all you
intend to use the radio for is hobby work on the 40 meter band, why mess
with success? However your 50' of wire should typically also tune up on 2182
khz sufficiently for the distance commonly covered by USCG Groups and
Caribbean RCC's (about 200 miles). Canadian Coast Guard Radio stations will
often answer vessels as far as 500 miles away. Higher bands of maritime
mobile channels would be better of course. I'm sure you're aware those
require a separate station license on your vessel. Good job on installing
your station. If you come up on maritime mobile maybe we'll get to talk
someday.

Jack Painter
Oceana Radio
Virginia Beach VA

"Bill Turner" wrote in message
...
On Fri, 26 Nov 2004 10:14:46 -0500, James wrote:

I'm trying to decide whether I need to
improve my antenna ground by adding a dynaplate (costly and requies the
boat to be taken from the water for installation) or whether the range I
am getting is decent.

__________________________________________________ _______

I'd say your system is working pretty well. 50 feet is too long for a
20 meter antenna, however. Your auto tuner is correcting for it, but a
shorter length will actually work better, since the auto tuner won't
have to introduce as much correction and therefore will have lower loss
in the tuner itself.

The vertical part of a ground plane antenna (which is what you have) can
be determined by the formula Feet=234/Freq, or for 14.3 MHz, 16.4 feet
(rounded off). The exact footage depends on variables in the immediate
environment, but that should be close enough. If you have to have a 50
foot overall wire because of the height of the boat's mast, just put an
egg insulator at the 16.4 foot length to break it up. For multiple
bands, figure the length of each section and put egg insulators where
needed, and then to change bands, just connect a jumper wire across
various eggs to get the correct length. Neat, huh? :-)

Also, you can't have too much ground area, within reason. More aluminum
foil or copper is always better.

If you have access to an SWR analyzer such as the MFJ 259, so much the
better. They are highly recommended for making and troubleshooting
antennas.

--
73, Bill W6WRT

Bill,

50 foot is only too long if you are sticking with the resonant length
situation. Which is not really necessary with his setup. In fact he
probably gets better versatility with the longer length. Just an opinion.

Dan/W4NTI

....Keep the 50 feet, use a tuner. Quit wasting good
'worry' on tuner losses, they don't amount to enough
to worry about. The 'additional' length (and that
tuner) gives you access to other bands. Will it be the
'best' possible antenna? Of course not, but it'll
certainly be adequate...
'Doc

'Doc wrote:
...Keep the 50 feet, use a tuner. Quit wasting good
'worry' on tuner losses, they don't amount to enough
to worry about. The 'additional' length (and that
tuner) gives you access to other bands. Will it be the
'best' possible antenna? Of course not, but it'll
certainly be adequate...
'Doc


Thanks for the feedback folks. Doc is on the right track. THe tuner
works really well (way to go SGC, nice product!) and the antenna length
doesn't seem to be impeding transmission distance.

Furthermore, the length, although not electrically correct for all
frequencies, is convenient physically for a sail boat.

Glad to hear that the 1000 mile distance I attained was acceptable
performance. My actual planned use is for keeping in touch with other
vessels (friends) that are within a couple of thousand miles tops.
Hopefully it will do the trick.

Thanks for the feedback folks. Muuch appreciated.

Jimmy

"Bill Turner" wrote in message
...
On Fri, 26 Nov 2004 10:14:46 -0500, James wrote:

I'm trying to decide whether I need to
improve my antenna ground by adding a dynaplate (costly and requies the
boat to be taken from the water for installation) or whether the range I
am getting is decent.

__________________________________________________ _______

I'd say your system is working pretty well. 50 feet is too long for a
20 meter antenna, however. Your auto tuner is correcting for it, but a
shorter length will actually work better, since the auto tuner won't
have to introduce as much correction and therefore will have lower loss
in the tuner itself.

The vertical part of a ground plane antenna (which is what you have) can
be determined by the formula Feet=234/Freq, or for 14.3 MHz, 16.4 feet
(rounded off). The exact footage depends on variables in the immediate
environment, but that should be close enough. If you have to have a 50
foot overall wire because of the height of the boat's mast, just put an
egg insulator at the 16.4 foot length to break it up. For multiple
bands, figure the length of each section and put egg insulators where
needed, and then to change bands, just connect a jumper wire across
various eggs to get the correct length. Neat, huh? :-)

Exactly what I was going to suggest. This will be easy to do if you have a
pully on the top end so you can easily drop the wire to change the shorting
straps. With the 50 foot wire, I would be concerned about getting high angle
radiation on 10/15/20 metters. Dog bone insulators might put less capacitive
loading on the top of the disconnected section.

Tam/WB2TT

Also, you can't have too much ground area, within reason. More aluminum
foil or copper is always better.

If you have access to an SWR analyzer such as the MFJ 259, so much the
better. They are highly recommended for making and troubleshooting
antennas.

--
73, Bill W6WRT

Bill Turner wrote:
On Sat, 27 Nov 2004 06:35:49 GMT, 'Doc wrote:


Will it be the
'best' possible antenna? Of course not, but it'll
certainly be adequate...
'Doc


__________________________________________________ _______

More cost, less performance. Amazes me what some people think is
"adequate".

I'd lose the tuner and spend the money on more goodies for the boat.

Oh, well.

--
Bill W6WRT


How about adequate performance and convenience?

Ever been aboard an ocean going sail boat when the waves hit 5 meters
and the wind is howling like a freight train? If not you can't imagine
the fury. I've been there. It's exhilirating but not easy to endure. In
fact it's damned hard work. That is NOT the time to be playing with
knobs and switches trying to tune for a particular band. Believe me, I
will have more imporant things to do. But I do want to know that I can
tranmsit immediately if something terrible happens by just keying the
mic. No fuss.

No offence but I've always been intrigued watching amateur enthusiasts
wiggling knobs and waggling switches. Reminds me of a scene from the
wizard of oz for some reason. Seems so unnecessary in this day and age.

CONVENIENCE is a VERY good a reason as any to use a tuner. And they're
not all that costly either. A few hundred bucks at best.

Just my 2 cents worth.

Jimmy

In article ,
Bill Turner wrote:

If you're a purist, a simple L-network at the base will
transform whatever impedance you have to exactly 50 ohms. L-networks of
this type are quite broadbanded and one setting will usually cover the
whole band.

Tuners, begone! :-)

--
Bill W6WRT

In what world does an "L network" not equal exactly what a tuner does
for a wire antenna? An autotuner is nothing more than a binary
incremented L Network with autofeedback of directional power, and phase.
You suggestion is the same thing with no feedback or incremental changes.


Me

In article ,
James wrote:

Thanks for the feedback folks. Doc is on the right track. THe tuner
works really well (way to go SGC, nice product!) and the antenna length
doesn't seem to be impeding transmission distance.

Furthermore, the length, although not electrically correct for all
frequencies, is convenient physically for a sail boat.

Glad to hear that the 1000 mile distance I attained was acceptable
performance. My actual planned use is for keeping in touch with other
vessels (friends) that are within a couple of thousand miles tops.
Hopefully it will do the trick.

Thanks for the feedback folks. Muuch appreciated.

Jimmy

With a 50' antenna length and an adiquate RF Ground, one could
consider that a respectable Marine Radio Installation.

One thing that needs to be understood is that ALL Autotuners
have a REALLY BIG difficency that is inherent in their design.
They can NOT tune wires at the Half Wavelength point and 50Khz on each
side. At this point antenna impedance becomes Infinite and can't be
tuned. so a boater must make sure that he never intends to transmit
on the frequency that is at the electrical Half Wavelength of the
antenna. He may need to lengthen ot shorten the wire to adjust
for this condition.


Bruce in alaska
--
add a 2 before @

On Fri, 26 Nov 2004 10:14:46 -0500, James
wrote:

Can anyone comment?

Hi James,

Well, as to the DX range, that has been responded to. So, to add to
all the comments in regard to height of antenna, tuners, automatic
tuners and the rest - another comment.

Take a fishing reel full of the Wireman's Flex weave (no doubt this
will provoke comments about wire corrosion) and drive it. Use your
hoist to pull out the correct height for any band.

I do take note of your admonition about fumbling with knobs, dials,
switches when a rogue wave is overtaking you. Your knottage may vary.

73's
Richard Clark, KB7QHC

Bill Turner wrote:
On Sat, 27 Nov 2004 11:51:01 -0500, James wrote:


Ever been aboard an ocean going sail boat when the waves hit 5 meters
and the wind is howling like a freight train? If not you can't imagine
the fury. I've been there. It's exhilirating but not easy to endure. In
fact it's damned hard work. That is NOT the time to be playing with
knobs and switches trying to tune for a particular band.


__________________________________________________ _______

Your point is well taken, but this is also NOT the time for equipment
failure. If that nifty tuner gets dunked with a dollop of salt water,
you are dead, RF wise. The KISS principle is your friend.

Anyone who can do a sail change or heave to in 5 meter waves can clip or
unclip a jumper, or better yet, will have the jumper set beforehand.

To each his own.

--
Bill W6WRT




Thanks for the words of wisdom Bill.

In fact I made a point of purchasing a tuner that comes in a water tight
(read that water PROOF according to the manfacturer) case. It's high
up mounted in a lazerette that "theoretically" stays dry. The ground and
antenna stud are both 316 Stainless (highly corrosion resistant and
intended for use in salt air). Furthermore, the electrical connection
between antenna stud and wire is soldered, crimped, and then heat shrunk
with adhesive lined shrink. Instead of using high tension wire for the
antenna connection to the backstay wire, I used tinned copper heavy
gauge insulated electrical wire. The environment that I live in is so
corrosive that, believe it or not I had to strip back the jacket to
expose the tinned copper wire, and then seal the cut edge of the jacket
to prevent salt water ingress between jacket and wire. If that isn't
done even tinned copper wire will corrode. Salt water will creep under
the jacket and corrosion will occur for a few feet distance from the
stripped jacket.

All connections (RF, power and control) between tuner and radio are made
with crimp and solder, then sealed with liquid electrical tape, then
adhesive lined heat shrink. I bought really big insulators to go at both
ends of the wire antenna too. Salt water is conductive and the larger
insulator with heavy ribbing will hopefully reduce the surface coating
of salty water to a level that precludes conductivity. Hopefully. the
copper wire I ran up the mast is on it's own pulley (well it will be
when I find time to go up the mast) and is already a lovely shade of
green. I have a spare, and hope this one lasts a year before needing
replacement.

Even so, I expect to have to service the connections about once a year
or so.

And you thought putting a beam on a tower was hard! Just thought you'd
find the lengths we have to go to in the ocean environment interesting.

The KISS principle is followed where ever I can too. I sincerely agree.
When things go badly on board, it's rarely one big bad thing that bites
ya. It's a string of small problems that...when combined, lead to a bad
day. I guess that's true in a lot of endeavors come to think of it. Last
time I was in a bad storm (a really bad one at that) I was on the radio
seeking information from someone else who had radar (I do not). My
autohelm had failed (a lousy 25 cent pin broke) and so I had to hand
steer in heavy seas. I couldn't leave the wheel. Fortunately the mic on
my marine VHF radio ~just~ reached the wheel from inside. Unfortunately
that is when I discovered that if I pulled on the mic cable it became
very intermittent. And that led to me spending a half hour trying to
raise a nearby boat with radar to ask which way the storm appeared to be
moving. Then the lightning started hitting the water all around
me...from there...well...let's just say it went downhill some.

Simple is good.

Thanks again for the feedback.

Bill,
In most cases, anything you do on a boat is a compromise between
what it 'ought to be' and what's possible. Since the backstay (or
frontstay) is ~there~ anyway, why not use it? Certainly not the
'best' thing in the world (whatever that is), but 'better' than most
alternative$.
Some people have a 'phobia' about tuners. If you don't want to
use one, that's fine. They do make 'things' much easier and the
difference in performance is 'acceptible' in most cases (acceptible
being relative). Since there are alternatives, pick the one you think
you can 'live' with and go with it. "You pays your money and takes your
choice", as they used to say in the house with the red velvet wall paper...
'Doc

PS - Not that I've ever been in one of those houses, I've just read
about them...

Oops, sorry.

The idea is to make it as 'idiot' proof as possible. That does
not, and will never mean the 'best'...
- 'Doc

"'Doc" wrote in message
.. .
Oops, sorry.

The idea is to make it as 'idiot' proof as possible. That does
not, and will never mean the 'best'...
- 'Doc


Make something "idiot-proof" and Nature will just make a better idiot.

73 - H

In article ,
James wrote:

the
copper wire I ran up the mast is on it's own pulley (well it will be
when I find time to go up the mast) and is already a lovely shade of
green.

You should replace the copper wire with the stuff the BIG BOYS use.
It is called Phospher/Bronze Antenna wire and it Doesn't turn green
when in contact with Seawater or salt air. Stuff was designed for this
spacific purpose.


Bruce in alaska
--
add a 2 before @

Bill Turner wrote:
Once the antenna is resonant, a simple L-C network will transform the
impedance to 50 ohms resistive and you are all set. Simple, cheap and
reliable, all the things a tuner is not.

And single-banded, one thing a tuner is not. :-)

The antenna need not be resonant. Under certain easily obtainable
conditions, the length of the open-wire transmission line can tune
a non-resonant antenna to system resonance and better the losses in
the coax feeding a resonant antenna. How to do that is described
on my web page.
--
73, Cecil http://www.qsl.net/w5dxp

Back to TX distance - you really need to get a good book on propagation and
understand the solar cycle and the characteristics of each band.

For example -- on 10M with the right time in the 11 year solar cycle -- a
minimum antenna and a few watts will work the world (at the right time of
day)

On 160M in the day time in the summer with low power -- you ain't going
anywhere

--
The Anon Keyboard
I doubt, therefore I might be



"Cecil Moore" wrote in message
...
Bill Turner wrote:
Once the antenna is resonant, a simple L-C network will transform the
impedance to 50 ohms resistive and you are all set. Simple, cheap and
reliable, all the things a tuner is not.

And single-banded, one thing a tuner is not. :-)

The antenna need not be resonant. Under certain easily obtainable
conditions, the length of the open-wire transmission line can tune
a non-resonant antenna to system resonance and better the losses in
the coax feeding a resonant antenna. How to do that is described
on my web page.
--
73, Cecil http://www.qsl.net/w5dxp

On Sun, 28 Nov 2004 12:06:48 -0800, Bill Turner
wrote:

On Sun, 28 Nov 2004 15:17:53 GMT, 'Doc wrote:

Since the backstay (or
frontstay) is ~there~ anyway, why not use it? Certainly not the
'best' thing in the world (whatever that is), but 'better' than most
alternative$.

There are insulators designed just for backstays which one could place
at the 16.4 foot level for 20 meters, or multiple locations for multiple
bands. In a home situation, I wouldn't care much but on a small boat on
the open sea, KISS could save your life, IMO.


Some people have a 'phobia' about tuners. If you don't want to
use one, that's fine.

The word "phobia" means a fear of. I'm certainly not afraid of tuners,
but I believe making the antenna right is better than using a device to
compensate for one that isn't. "Bias" would be a better word.

Once the antenna is resonant, a simple L-C network will transform the
impedance to 50 ohms resistive and you are all set. Simple, cheap and
reliable, all the things a tuner is not.


They do make 'things' much easier and the
difference in performance is 'acceptible' in most cases (acceptible
being relative).

Sigh.

It's kind of difficult to get a resonant quarter wave into a back stay
as you don't usually know where ground is. Ground can be any number of
feet from where the feed point is on a boat. Every thing above real
ground is antenna.

73
Gary K4FMX

Bill Turner wrote:
A simple pigtail with a banana plug would make the L-network as multi
banded as you have L-networks. Still simple, cheap and reliable.

Let's see, would I rather switch knife switches at my operating
position or go outside in a Texas Thunder Storm to attach the
pigtails? At my age, I could develop pneumonia or catch the flu
(no flu shot this year). Pneumonia and/or flu is not simple or
cheap. Think I'll stick with my Ladder-Line Length Selector. :-)

Moral: Use virtually lossless transmission line and do all the
matching in the comfort of the shack.
--
73, Cecil http://www.qsl.net/w5dxp

Bill I agree But
The original poster sed:

"My very first contacts were established with 2 land stations on 14300 at
100W that were about 1000 miles away. They both reported that my signal
was good and that it sounded like I was "sitting right next to them". I
have no idea if this was a good distance, great, or mediocre."

So I assume he was after contacts of several hundred (thousand) miles - not
ground wave.

My point was this for the 160M band (From a book on propagation)

"160 meters. Daytime conditions for this band suffer from extreme D-layer
absorption, reducing the amount of signal to levels far below the noise
floor of our receivers. This limits daytime coverage to essentially
ground-wave coverage. At night, the D layer dissipates rapidly and worldwide
160-meter communication becomes possible via the F2-layer and in ducts in
the electron density valley above the E region peak. Depending on the
propagation mode, high or low elevation angles may be required. A limiting
factor is the noise levels prevalent at these frequencies, both atmospheric
and man-made as well as tropical and mid-latitude thunderstorms which cause
high levels of static in the summer season. Winter conditions are much
better, making winter evenings the best time to work 160-meter DX.

So you might have ground wave on 160M during the day to 100 miles or so.

See URL for details and formulas on ground wave distances
http://www.qsl.net/g3cwi/Downloads/Propagation%201.doc


As I sed --- way too much on propagation to put on a post and cover all the
variables and details -- the original poster needs to get a good book or at
least look at this free URL
http://www.ae4rv.com/tn/propflash.htm

And of course -- "on 10 meters at the
bottom of the sunspot cycle 10 is open nearly every day to
somewhere."

Sure -- ground wave and perhaps sporadic-E

--
The Anon Keyboard
I doubt, therefore I might be



"Bill Turner" wrote in message
...
On Sun, 28 Nov 2004 13:01:47 -0800, "Keyboard In The Wilderness"
wrote:

On 160M in the day time in the summer with low power -- you ain't going
anywhere

__________________________________________________ _______

This is true but not for the reason you might think. 160 meters has
excellent groundwave propagation; better than any other amateur band in
fact, but the lack of stations is the real reason 160 is mostly dead in
the daytime. It's a self fulfilling prophecy - nobody is on, so I'm not
going to get on either. The same thing happens on 10 meters at the
bottom of the sunspot cycle even though 10 is open nearly every day to
somewhere.

--
Bill W6WRT

OOppps you are right -- I shouldn't have sed anywhere.
Of course ground wave may get out to 100 miles.

See my other post

--
The Anon Keyboard
I doubt, therefore I might be



"Bill Turner" wrote in message
...
On Sun, 28 Nov 2004 13:01:47 -0800, "Keyboard In The Wilderness"
wrote:

On 160M in the day time in the summer with low power -- you ain't going
anywhere

__________________________________________________ _______

This is true but not for the reason you might think. 160 meters has
excellent groundwave propagation; better than any other amateur band in
fact, but the lack of stations is the real reason 160 is mostly dead in
the daytime. It's a self fulfilling prophecy - nobody is on, so I'm not
going to get on either. The same thing happens on 10 meters at the
bottom of the sunspot cycle even though 10 is open nearly every day to
somewhere.

--
Bill W6WRT

Bill Turner wrote:
On Sun, 28 Nov 2004 16:01:33 -0600, Cecil Moore
wrote:


Let's see, would I rather switch knife switches at my operating
position or go outside in a Texas Thunder Storm to attach the
pigtails? At my age, I could develop pneumonia or catch the flu
(no flu shot this year). Pneumonia and/or flu is not simple or
cheap. Think I'll stick with my Ladder-Line Length Selector. :-)


__________________________________________________ _______

You misunderstand. On a sailboat, the pigtails for selecting L-networks
could (and should) be inside the boat, right under the eyepad for the
antenna.

Pneumonia not required.

--
Bill W6WRT


No possible way that could be accomodated with any degree of safety or
convenience at all Bill.

On a sailboat, the conventional way to run a long piece of wire is up
the mast at the stern. Either a wire or an insultated backstay is used.
The backstay is the guy wire at the back of the boat holding the mast
up. Insulators can be cut into the backstay allowing it to be used as an
antenna. I don't care for that much as it seems possible for the
backstay insulators to fail (even though the manufacturers claim
otherwise), leading to a dismasting. People die that way. So I run a
simple copper wire up the back between the 2 backstays.

At the stern of most sailboats, there are exterior storage lockers. A
very heavy stainless steel "chain plate" is attached to the hull at the
stern, and the back stay (or in my case stays, as I have two) are
attached to those chain plates. My chain plates are right on the transom
which is typical of most sailboats. That's RIGHT at the back of the
boat. There is a stern locker nearby for storage of stuff you want to
use in the cockpit. That is a typical layout for most sailboats. Then,
heading forward there is a cockpit area, then the companionway down into
the cabin. Below the cockpit is engine, and no living space. The
livingspace typically begins at the companionway.

Typically, the radio is located at the nav station, which is midship in
the cabin, in my case about 15 feet from the stern locker where the
tuner is located. My boat is quite typical of most sailboats. There is
no living space in the vicinity of the transom nor is there living space
under the cockpit. Some sailboats feature a center cockpit, in which
case a large master stateroom is usually under the back of the boat.
That's not where a radio belongs either. It belongs at the nav station.

In other words, in order to use pigtails "right under the antenna" as
you suggest I would have to go outside of the cabin by climbing up the
companionway, walk to the very back of the boat (a place you do not want
to be when in heavy weather), open a stern locker, get down on my hands
and knees and fiddle with the pigtails whilst pitching about as if in a
washing machine of the spin cycle. Then go (stagger really) back inside
to use the radio. Switch bands? Do the whole thing again. By the way in
heavy weather, leaving the cabin also entails strapping on a heavy
safety harness, possibly foul weather wear, and then attaching the
safety harness to a line that is attached to the boat, before exiting
the cabin. As you can surely appreciate, pigtails or any other
mechanical connections to be messed with would simply not work in the
environmnent.

Simply put, the only practical solution on a sailboat is a tuner. That
is why I have never yet (in over 25 years of serious messing with boats
and countless sea miles under my keel) seen a ham or marine SSB equipped
boat without a tuner.

It is the ONLY practical solution.

There should be no problem at all with some of the antenna being below
deck. It would be good to keep it away from metal stuff of course.
Longer horizontal runs tend to raise issues, though. Probably a greater
chance of coupling rf into the boat's other electrical systems, and a
long run of 20 feet or so (say from the backstay to a nav station
amidships) can radically alter the radiation pattern. Maybe for the
good, maybe not. And that is the main reason that manual tuners are
questionable choices for use with backstay antennas. Nobody wants to try
to manually tune a backstay antenna located at the stern if the rig is
15=20 feet away.

To avoid this run, some of us have resorted to loading the shrouds (and
the whole rig as well) with an L-network quite successfully. I believe a
separate wire run up a flag halyard would be an easier antenna to tune,
but it would introduce other issues.

As Gary has said, it is difficult (but only mildly so) to get a resonant
quarter-wave in a backstay. It would probably require an antenna
impedance analyzer to find resonance. Make it a bit short and add a few
turns of wire (cheap and reliable) to bring it to resonance.


Chuck



Bill Turner wrote:
On Sun, 28 Nov 2004 21:15:13 GMT, Gary Schafer
wrote:


It's kind of difficult to get a resonant quarter wave into a back stay
as you don't usually know where ground is. Ground can be any number of
feet from where the feed point is on a boat. Every thing above real
ground is antenna.


__________________________________________________ _______

Correct. For simplicity, figure the feed point is right where the coax
shield connects to the ground plane. As you said, everything above that
is antenna. On a fiberglass sailboat, the hull is quite transparent to
RF on HF frequencies, so the presence of a few feet of antenna inside
the hull is of no consequence.

--
Bill W6WRT

On Sun, 28 Nov 2004 19:10:51 -0500, James wrote:

Bill Turner wrote:
On Sun, 28 Nov 2004 16:01:33 -0600, Cecil Moore
wrote:


Let's see, would I rather switch knife switches at my operating
position or go outside in a Texas Thunder Storm to attach the
pigtails? At my age, I could develop pneumonia or catch the flu
(no flu shot this year). Pneumonia and/or flu is not simple or
cheap. Think I'll stick with my Ladder-Line Length Selector. :-)


__________________________________________________ _______

You misunderstand. On a sailboat, the pigtails for selecting L-networks
could (and should) be inside the boat, right under the eyepad for the
antenna.

Pneumonia not required.

--
Bill W6WRT


No possible way that could be accomodated with any degree of safety or
convenience at all Bill.

On a sailboat, the conventional way to run a long piece of wire is up
the mast at the stern. Either a wire or an insultated backstay is used.
The backstay is the guy wire at the back of the boat holding the mast
up. Insulators can be cut into the backstay allowing it to be used as an
antenna. I don't care for that much as it seems possible for the
backstay insulators to fail (even though the manufacturers claim
otherwise), leading to a dismasting. People die that way. So I run a
simple copper wire up the back between the 2 backstays.

At the stern of most sailboats, there are exterior storage lockers. A
very heavy stainless steel "chain plate" is attached to the hull at the
stern, and the back stay (or in my case stays, as I have two) are
attached to those chain plates. My chain plates are right on the transom
which is typical of most sailboats. That's RIGHT at the back of the
boat. There is a stern locker nearby for storage of stuff you want to
use in the cockpit. That is a typical layout for most sailboats. Then,
heading forward there is a cockpit area, then the companionway down into
the cabin. Below the cockpit is engine, and no living space. The
livingspace typically begins at the companionway.

Typically, the radio is located at the nav station, which is midship in
the cabin, in my case about 15 feet from the stern locker where the
tuner is located. My boat is quite typical of most sailboats. There is
no living space in the vicinity of the transom nor is there living space
under the cockpit. Some sailboats feature a center cockpit, in which
case a large master stateroom is usually under the back of the boat.
That's not where a radio belongs either. It belongs at the nav station.

In other words, in order to use pigtails "right under the antenna" as
you suggest I would have to go outside of the cabin by climbing up the
companionway, walk to the very back of the boat (a place you do not want
to be when in heavy weather), open a stern locker, get down on my hands
and knees and fiddle with the pigtails whilst pitching about as if in a
washing machine of the spin cycle. Then go (stagger really) back inside
to use the radio. Switch bands? Do the whole thing again. By the way in
heavy weather, leaving the cabin also entails strapping on a heavy
safety harness, possibly foul weather wear, and then attaching the
safety harness to a line that is attached to the boat, before exiting
the cabin. As you can surely appreciate, pigtails or any other
mechanical connections to be messed with would simply not work in the
environmnent.

Simply put, the only practical solution on a sailboat is a tuner. That
is why I have never yet (in over 25 years of serious messing with boats
and countless sea miles under my keel) seen a ham or marine SSB equipped
boat without a tuner.

It is the ONLY practical solution.


Aman James! The autotuner is the bet thing since sliced bread for a
boat.

73
Gary K4FMX

On Sun, 28 Nov 2004 15:20:37 -0800, Bill Turner
wrote:

On Sun, 28 Nov 2004 21:15:13 GMT, Gary Schafer
wrote:

It's kind of difficult to get a resonant quarter wave into a back stay
as you don't usually know where ground is. Ground can be any number of
feet from where the feed point is on a boat. Every thing above real
ground is antenna.

_________________________________________________ ________

Correct. For simplicity, figure the feed point is right where the coax
shield connects to the ground plane. As you said, everything above that
is antenna. On a fiberglass sailboat, the hull is quite transparent to
RF on HF frequencies, so the presence of a few feet of antenna inside
the hull is of no consequence.

When I said "you don't usually know where ground is" I meant that on a
boat what may look like real ground may not be. Usually there are a
lot of different things tied together to try and get a decent ground
for the radio. The length of those leads are a factor. There is no way
to know for sure how long the actual ground lead is without measuring
where your antenna resonates.

Cut and try with a backstay is not practical.


73
Gary K4FMX

Cecil,
Changing feed line length is a viable option for a land
station, but a not-so-viable option for a sailboat. Where/how
do you place it to keep it out of the way?
'Doc

"James" wrote in message
.. .
Bill Turner wrote:
On Sun, 28 Nov 2004 16:01:33 -0600, Cecil Moore
wrote:


Let's see, would I rather switch knife switches at my operating
position or go outside in a Texas Thunder Storm to attach the
pigtails? At my age, I could develop pneumonia or catch the flu
(no flu shot this year). Pneumonia and/or flu is not simple or
cheap. Think I'll stick with my Ladder-Line Length Selector. :-)


__________________________________________________ _______

You misunderstand. On a sailboat, the pigtails for selecting L-networks
could (and should) be inside the boat, right under the eyepad for the
antenna.

Pneumonia not required.

--
Bill W6WRT


No possible way that could be accomodated with any degree of safety or
convenience at all Bill.

On a sailboat, the conventional way to run a long piece of wire is up the
mast at the stern. Either a wire or an insultated backstay is used. The
backstay is the guy wire at the back of the boat holding the mast up.
Insulators can be cut into the backstay allowing it to be used as an
antenna. I don't care for that much as it seems possible for the backstay
insulators to fail (even though the manufacturers claim otherwise),
leading to a dismasting. People die that way. So I run a simple copper
wire up the back between the 2 backstays.

At the stern of most sailboats, there are exterior storage lockers. A very
heavy stainless steel "chain plate" is attached to the hull at the stern,
and the back stay (or in my case stays, as I have two) are attached to
those chain plates. My chain plates are right on the transom which is
typical of most sailboats. That's RIGHT at the back of the boat. There is
a stern locker nearby for storage of stuff you want to use in the cockpit.
That is a typical layout for most sailboats. Then, heading forward there
is a cockpit area, then the companionway down into the cabin. Below the
cockpit is engine, and no living space. The livingspace typically begins
at the companionway.

Typically, the radio is located at the nav station, which is midship in
the cabin, in my case about 15 feet from the stern locker where the tuner
is located. My boat is quite typical of most sailboats. There is no living
space in the vicinity of the transom nor is there living space under the
cockpit. Some sailboats feature a center cockpit, in which case a large
master stateroom is usually under the back of the boat. That's not where a
radio belongs either. It belongs at the nav station.

In other words, in order to use pigtails "right under the antenna" as you
suggest I would have to go outside of the cabin by climbing up the
companionway, walk to the very back of the boat (a place you do not want
to be when in heavy weather), open a stern locker, get down on my hands
and knees and fiddle with the pigtails whilst pitching about as if in a
washing machine of the spin cycle. Then go (stagger really) back inside to
use the radio. Switch bands? Do the whole thing again. By the way in heavy
weather, leaving the cabin also entails strapping on a heavy safety
harness, possibly foul weather wear, and then attaching the safety harness
to a line that is attached to the boat, before exiting the cabin. As you
can surely appreciate, pigtails or any other mechanical connections to be
messed with would simply not work in the environmnent.

Simply put, the only practical solution on a sailboat is a tuner. That is
why I have never yet (in over 25 years of serious messing with boats and
countless sea miles under my keel) seen a ham or marine SSB equipped boat
without a tuner.

It is the ONLY practical solution.

I notice nobody has mentioned traps. That would be another way. 50 feet is
long enough to have it work 75 meters, if there are several traps in line.
From what I understand, the antenna is mostly vertical. Tuner or not, a 50
foot vertical is getting to be too long for low angle radiation at the
higher bands.

Tam/WB2TT

Not a bad idea, if Wireman's Flex Weave is stainless steel. Anything
else will be corroded before you know it. Perhaps stainless steel
aircraft cable?

Absolutely. Replace your 50 feet of copper with stainless steel wire. Mount it
carefully and you'll get 10 years out of that. Keep the tuner. Its one thing to
have resonant lengths or traps on the harmonically related ham bands but
someday, when the swell is 25 foot in a force 9 and your drifting towards
rocks, being able to instantly tune and call on 2182Khz or one of the higher
distress freqs may very well save your life, believe me, Im a lifeboat man.
But, taking others views on board, as part of your regular planned maintenance
(you do that dont you?), take the lid off your transciever AND tuner to check
for corrosion, youll recognise it as white flaky stuff where the shiny bits
were last year! Other than that, your tuner is no more likely to breakdown than
anything else on your boat.

John, G0WPA

"John - G0WPA" wrote in message
...
snip

Im a lifeboat man.

Oh if only I had your fortitude and courage.
Storms around the U.K.rocky shores require special men
who have no thoughts of mortality
Cheers
Art


Bsnip anything else on your boat.

John, G0WPA