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  #21   Report Post  
Old November 28th 04, 10:31 PM
Keyboard In The Wilderness
 
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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



  #22   Report Post  
Old November 28th 04, 10:36 PM
Keyboard In The Wilderness
 
Posts: n/a
Default

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



  #23   Report Post  
Old November 29th 04, 12:10 AM
James
 
Posts: n/a
Default

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.
  #24   Report Post  
Old November 29th 04, 12:49 AM
Chuck
 
Posts: n/a
Default

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

  #25   Report Post  
Old November 29th 04, 03:10 AM
Gary Schafer
 
Posts: n/a
Default

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


  #26   Report Post  
Old November 29th 04, 03:18 AM
Gary Schafer
 
Posts: n/a
Default

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
  #27   Report Post  
Old November 29th 04, 01:55 PM
'Doc
 
Posts: n/a
Default

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

  #28   Report Post  
Old November 29th 04, 03:25 PM
Tam/WB2TT
 
Posts: n/a
Default


"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


  #29   Report Post  
Old December 10th 04, 12:09 AM
John - G0WPA
 
Posts: n/a
Default

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


  #30   Report Post  
Old December 10th 04, 02:22 AM
 
Posts: n/a
Default


"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




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