triadic stay ssb

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13 years 3 months ago #701 by Lisa Cornelius
Replied by Lisa Cornelius on topic Re:triadic stay ssb
Hi Again, Joe describes the way most people have installed their SSB. This setup is traditional. It does work...sort of. It does waste most of the performance of your SSB. A 150 watt transmitter may have very poor performance and still work, but it is wasting much of its output. I could use a 5 watt transmitter on my setup and probably get similar performance. Most of the efficiency is in the Antennae system. If one takes a fluorescent tube and checks for example... the 90 deg bend of the wide copper foil... one sees a significant portion the RF energy emitted straight out and not following the bend. The Electric Field and Magnetic Field of the RF wave is pulsing millions of times per second. It is high frequency Alternating Current. It interacts with the surface electron cloud of the copper foil via Inductive and Capactive Reactance in a manner that is not intuitive to most humans. The surface electron fog on the copper foil almost acts as a wave guide to the RF wave. No sharp bends please. Also any connection is an interface. A significant portion of the RF energy is reflected at that junction. Best to not have connections. When I was at the Amundsen South Pole station I had a oscilloscope, spectrum analyzer, absorptive power meter, and a very nice crossed needle Standing Wave Ratio meter. I measured and experimented a great deal. A good lay overview of REFLECTIONS and SWR here: www.ycars.org/EFRA/Module%20C/TLSWR.htm Click on the Animations to see the principles. click back to continue reading. Animations are much better than using the math tools.

That rope antennae link is your best bet. http:\\www.ropeantnnae.com It is a compromise. All things on a sailboat are compromise. One must raise the antennae to use it. Not a good thing in a ice storm. But I can select appropriate lengths by gently bending the "7" shape of my raised GTO-15 wire (high voltage wire used in Neon Signs) for the frequency I am using at that moment. I can modify the geometry as needed for that use. The Hallard is attached at the gentle bend in the seven shape. The SKY Wave is sprung and launched out into space at that bend. The GROUND WAVE is emitted horizontal and parallel to the sea surface for shorter distances.
One can use lower frequencies and GROUND WAVE to talk to past the VHF range of 25 miles or so...up to several hundred miles with HF.
I use this ground wave many times when using my Proctor III modem and Sailmail to send an email in noisy conditions.

If anyone wants to experiment. I would be glad to try contact. I could send an email test too via Saimail if you want.
This software calculates the best frequencies and times to try.
greg-hand.com/hf.html Greg Hand is really smart! This software works great.

background info for education: www.weather.nps.navy.mil/~psguest/EMEO_o...le3/module_3_2b.html
This shows the layers of the ionsphere and how to find the optimum freq. FOT and others... MUF LUF etc...




BEST COMPROMISE on a sailboat
I made one but you can buy one here:

www.ropeantenna.com/
Dr. John Gregory, a RF designer, with a specialty in marine RF communications. The antenna has been tested extremely successfully on many different sizes and models of vessels. www.ropeantenna.com/Technical%20details.htm Read this to get the Technical Details of why it is worth the effort.

p.s.
When I was at South Pole we ONLY had HF Radio. We had a beamed Yagi and Log Periodic anteannae.
Grounding was a problem sitting on 9000 feet on almost insulating dielectric ice. \
So we had a Counterpoise challenge too.

No satellite, no internet like now.

Sometimes we could not hear the world for days or weeks due to solar storms.
OAE used to be a term used as a term of endearment between winter-overs.

Patrick on Gaia,
Old Antarctic Explorer OAE from the South Pole Radio Shack

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13 years 3 months ago #702 by Joe Barnes
Replied by Joe Barnes on topic Re:triadic stay ssb
It is always fun and interesting to learn about better techniques and materials. In the boating world, a lot of things have remained the same, but electronics have definitely made a huge difference and the technology and understanding is improving fast. Patrick gave info that I was not aware of in 2003 when I put in our SSB radio system. The information that he has may have been available back then, but I did not find it. Kudos to Patrick for bringing the latest and greatest thought on the installation of SSB's, and especially the links to RopeAntenna and the other online articles.

I have no doubt that the "rope antenna" would be far superior to using a stay with a GTO-15 cable attached such as what I installed. I do wonder how well it would do in a gale, and whether it would be fun to run it up during one if it weren't permanently mounted. It would have windage like any other rigging and would have to be properly tensioned to avoid whipping around. I would want to have my antenna up all the time since weather is unpredictable and often the time you most need good radio contacts (weather faxes, other stations, etc.) is when the sea is at its worst.

I would be interested in anyone's experience or preferences on this.

I was not aware of sharp angles on copper strip to be bad. This was the common, and recommended, practice 7 years ago. The issue is to be able to route the strip in such a way to avoid any sharp bends. If I had to do it over again, I would have installed an exterior ground plane, and I would use the "ladder" strip as noted in one of the articles.

But again, very informative information. If I were fitting out a boat now, I would implement Patrick's advice, but with some concern on raising and lowering a rope antenna.

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13 years 3 months ago #703 by Lisa Cornelius
Replied by Lisa Cornelius on topic Re:triadic stay ssb
Good Morning Joe and all Captains,

Joe, Wish I had all the experiences you have had in your real world sailing across the Pacific, New Zealand, Australia.
Please call me sometime to chat. 302-286-7134 Come sailing with me anytime in the Chesapeake, Please.
Do you know about towed HydroGenerators?

Joe is absolutely correct. During bad weather is just the time you may need the SSB and going out on deck to fiddle with raising an antennae is not optimum. I simply could not do it last week during the ice storm...too dangerous.
But what if the mast is gone? What if the backstay is gone? Options? Backups?

Rope Antannae can be put up in an emergency situation in just a few minutes...hooked to whatever.

The Rope Antennae has a permanent option too. It uses Stayset from New England Ropes. One can tension it well to keep flapping, flopping to a minimum and it can be kept up permanently. The outer braiding can take up to 3000lbs of tension without straining the wire inside. I will buy two as a backups to my braided GTO-15 high voltage wire that I currently use. The disadvantage will be a static geometry and of course, it will be at the mercy of the weather/corrosion. Currently my antennae is kept stowed and away from salt, sun, and water 99.9 % of the time. With a static geometry one will be optimized for only one frequency range. What if the sun and/or the ionosphere is not cooperating on that frequency range? Then you simply will not get that weather info you desperately need. That E layer and F layer change all the time folks. The Ground Wave changes too. Look at the software link I sent last time. It predicts the optimum FREQUENCIES and TIMES to try.

Options are good! Backups are good! Especially if your mast has just gone away...no backstay...no SSB antennae just when you need it most.

OTHER IMPORTANT DETAILS...the devil is in the details...Silicon Bronze studs, washers, nuts please, Gold Coated please.
Seal well. No moisture please. Go thru the entire slide show to see the details(see the slide controls at bottom)
....VERY IMPORTANT DETAILS. No connections best...just continuous...eliminates reflections of RF that simply go to heat your boat. i.e. Connect SSB RADIO DIRECTLY to BATTERIES via fuse not circuit breaker and use very heavy wire... minimize voltage drop please.

A nice circular gold foil tapering to a point at the end inside a 30,000 volt insulator cover would be the very best rope antannae, but we do not live in Utopia.
So use braid copper/silver/nickel that is tinned...marine grade inside the Stayset New England Rope ...or buy one already made.

The permanent installation of the Rope Antennae is Here: www.cruiseEmail.com or
www.ropeantenna.com/
Dr. John Gregory, a RF designer, with a specialty in marine RF communications. The antenna has been tested extremely successfully on many different sizes and models of vessels.
www.ropeantenna.com/Technical%20details.htm
Read this to get the Technical Details of why it is worth the effort.

Questions:

Dr. John Gregory John Sloop

w3ate@att.net jsloop@austin.rr.com

954-815-8411 512-779-5695

p.s. this link did not come out correctly in my last email

background info for education:
www.weather.nps.navy.mil/~psguest/EMEO_o...le3/module_3_2b.html
This shows the layers of the ionsphere and how to find the optimum freq. FOT and others... MUF LUF etc...


Any takers on attempting contact via SSB?
When Al Hales and Ellen (Phoenix) were in the Bahamas (Exhumas) we made contact nicely from Delaware.

Patrick on Gaia

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13 years 3 months ago #704 by Lisa Cornelius
Replied by Lisa Cornelius on topic Re:triadic stay ssb
Hi Again,

The important education link still did not come out correctly on the Whitby site:

Please copy this entire line and paste it into your browser.


background info for education:



www.weather.nps.navy.mil/~psguest/EMEO_o...le3/module_3_2b.html




This shows the layers of the ionsphere and how to find the optimum freq. FOT and others... MUF LUF etc...

www.weather.nps.navy.mil/~psguest/EMEO_o...le3/module_3_2b.html


=====> EXERPT ======= see the animations too....this info is from the NAVY post grad school...good stuff!

HF Radiation - Choosing the Right Frequency
Learning Objectives

* Be able to explain to radio operators and other technicians what controls HF propagation under normal conditions.
* Be able to explain how various environmental and engineering factors control the values of the plasma frequency, the critical frequency (fo), the maximum usable frequency (MUF), the lowest usable frequency (LUF) and the frequency of optimum transmission (FOT) and why these parameters are important to HF.
* Be able to use model predictions of these parameters to determine the best HF frequency to use for a particular situation or mission.

Introduction
We've seen HF frequencies make use of the skywave mode that allows long distance transmissions. The specific frequency to use depends on ionospheric conditions, which are constantly changing. Choosing the best frequency to use for a given situation is not a trivial task. Most HF radio operators have a general idea how frequencies change as a function of the time of day, and they know that sometimes there are problems. But many of them don't understand the nature of the required frequency changes and the problems that sometimes occur. This web page will describe how you can make the best choice for frequency. This requires the use of computer models that can been run locally or from model and observed data available on the Internet. In order to use these models and Internet sources, you need to know something about how the ionosphere affects HF radiation. You also need to understand the terminology that is used by the models and sources providing information on HF communications. This page concerns normal conditions that we can expect most of the time. Later, we will consider "space weather" which creates less frequent but potentially disruptive events.
Plasma Frequency

All matter consists of positively-charged protons and negatively-charged electrons. (There are other "subatomic" particles, but we don't need to concern ourselves with these here.) For most matter that we are familiar with (gases, liquids and solids) one or more protons are grouped together to form a nucleus while electrons swarm around them; this is called an atom. A "neutral" atom has the same number of electrons and protons; this it the typical situation here on the surface of the earth. Earlier we discussed how in the ionosphere, radiation and particles from the sun can knock electrons away from atoms, resulting in negatively-charged "free electrons" and positively-charged ions. The amount of free electrons that are present is called the electron density.

Free electrons are not attached to a particular nucleus. Matter in this form is called "plasma". In a plasma, the negative free electrons and the positive ions are attracted to each other by the electromagnetic force, but they are too energetic to stay fixed together an atom. As a result the free electrons and ions vibrate back and forth. The frequency of vibration depends on the number of free electrons (see Figure 1).

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13 years 3 months ago #705 by Joe Barnes
Replied by Joe Barnes on topic Re:triadic stay ssb
Thanks for the much more expert, and more recent, thoughts about the best way to install SSB's and antennas on boats. No one should take my comments as from an expert, as I am not, and I hope no one took my comments as such. We met many people who had much more sophisticated setups than we did, but ours met our needs at the time. I am somewhat an expert on electric systems on boats, but anything else I contribute will be solely based on our personal experience. For radios and specifically SSB's,we would defer to the people who have studied this far more than we have. That is one of the best things about this forum.

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13 years 3 months ago #708 by Lisa Cornelius
Eureka, I finally found this from the Australian Govt.

Very good info on the Ionosphere and HF comms ...with diagrams

www.ips.gov.au/Category/Educational/Othe...0to%20HF%20Radio.pdf


When one knows the concepts of how the signal propagates, it allows the operator to choose the TIME/FREQ to optimize the communications. The propagation models are a necessity as well as the Solar Conditions reports.


Perhaps of Interest:

One of our National Science Foundation experiments my second winter-over in Antarctica was on "Whistlers"
en.wikipedia.org/wiki/Whistler_%28radio%29

RF from Lightning discharges in the Northern Hemisphere propagate in "wave guides" and
appear at the conjugate points in the Southern Hemisphere as WHISTLERS.
We had a VLF and ELF antennae. Nuclear Subs use these frequencies.
There are recordings of how they sound on these links.
Mike Trimpi from Standford Univ. was working for the Principal Investigator PI
Mike is famous for discovery of the Trimpi Effect (electron bubbles in the E layer)
en.wikipedia.org/wiki/Whistler_%28radio%29
Miek saw these Sferic signals propagated via the "wave guide" of our planet's inosphere layers.
en.wikipedia.org/wiki/Sferic

When one listens on HF on your SSB in the various modes AM, SSB, CW, etc...
One can hear the Over the Horizon Radar = the Russian Woodpecker
Whistlers, and many other interesting sources of noise, even noise of our Sun and other suns and objects in space

Patrick

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