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Old 30-04-2013, 11:43   #46
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Re: My SSB Install Was a Breeze

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Originally Posted by SeaBuffalo View Post
.......

Bill when you saw vertical dipole can you give specifics like length, center fed , commercial made support structure and a picture.
Sure. Pics and construction details are here:
Marine Antennas

Just click on each pic twice for full resolution.

Been using and writing about vertical dipoles for decades, beginning with an article in QST Magazine in December 1976.

Bill
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Old 30-04-2013, 11:45   #47
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Re: My SSB Install Was a Breeze

Bill is the man.
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Old 30-04-2013, 13:01   #48
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Excellent pictures and info. For some reason when your said dipole I pictured a freestanding fiberglass dipole that's center fed.

I had thought of what you did in the past but always had concerns about the interaction with the rigging on both a SWR / impedance issue and radiation pattern. Does the mast, rigging or other dipole cause any yagi effect with radiation direction or do they pretty much act as a omni?

Also what kind of tuner are you using for the dipoles to move around the band and have you had any luck with getting either dipole to work effectively in other bands with manual tuner?
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Old 30-04-2013, 13:03   #49
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Re: My SSB Install Was a Breeze

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Originally Posted by btrayfors View Post
The magic of GTO-15 wire is the "15". It stands for 15,000 volts, which is the voltage it will withstand before breaking down.

There are high voltage points along the antenna and its feedline....nothing like 15,000 volts....but still potentially troublesome. These could cause insulation breakdown and arcing in the proximity of standing rigging. Hence the prescription to use GTO-15 which is CHEAP and READILY AVAILABLE from West Marine, many online sites, etc. It's essentially neon sign wire, so you could find some at any electric sign shop.

Most GTO-15 used in SSB installations has a single AWG14 stranded wire conductor. Thus, any AWG14 or larger feedline could easily carry the 150 RF watts. It's just that plain old stranded wire doesn't normally have insulation which will handle the higher voltages without the potential for breakdown as well as GTO-15.

High voltage points and high current points are distributed all along the antenna feedline and the antenna itself, with the highest voltage point being at the very end. With a 100-150 watt transmitter such as those in common SSB use, these can be as much as several thousand volts. They are normally much lower along the antenna itself, but typically are still several hundred volts.

Bill
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Sent from my boat in a freshwater marina where I just checked into the MM Net on 14300 kHz using a vertical dipole antenna on the bow and where I always receive very strong signal reports....you can't beat a vertical dipole!

For comparison, I asked the Net Control Station in Minneapolis (KC0YHM)for a comparative signal report, using first the vertical dipole and next the traditional backstay antenna. He said, "Night and day; you were S9 on the vertical dipole, and S3-4 on the backstay antenna".

B.
Bill...thanx for all your info and constructive help. What I'm not understanding is the voltage thing. I am aware of the RF energy generated but not the voltage. Could you elaborate?...CS
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Old 30-04-2013, 14:44   #50
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Re: My SSB Install Was a Breeze

Quote:
Originally Posted by SeaBuffalo View Post
Excellent pictures and info. For some reason when your said dipole I pictured a freestanding fiberglass dipole that's center fed.

I had thought of what you did in the past but always had concerns about the interaction with the rigging on both a SWR / impedance issue and radiation pattern. Does the mast, rigging or other dipole cause any yagi effect with radiation direction or do they pretty much act as a omni?

Also what kind of tuner are you using for the dipoles to move around the band and have you had any luck with getting either dipole to work effectively in other bands with manual tuner?
The dipoles I use are single-band only. They do not require a tuner or external counterpoise/RF ground of any kind.

I believe strongly that an antenna on a boat must be able to stand up to the marine environment, including major storms. These dipoles will do that. They can be left in place when at anchor or dockside, and are quickly set up for sailing by simply undoing the lower end and moving it back into the shrouds (where they will work OK, but with some de-tuning).

It is possible to set up multi-band dipoles using traps or open wire feedline and a tuner. However, in my judgment and experience these are not real seagoing antennas because traps are messy and add windage and flop around in a seaway, and because open wire feeders won't stand up to high wind and sea conditions. They're OK at anchor or dockside though...like the G5RV Junior if you have a big enough boat.

Re: radiation pattern, you can't do much about horizontal patterns. They are what they are, they differ with each boat, and are largely a function of the standing rigging, mast(s), etc. However, vertical dipoles rigged low (with the lower end close to the deck) have a very low vertical angle of radiation which is why they are such great antennas for DX. A vertical dipole will put most of its radiated energy just a few degrees above the horizon, which is what you want for DX.

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Old 30-04-2013, 14:55   #51
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Re: My SSB Install Was a Breeze

Bill as always is correct. I'm now using a delta loop at home with a SG 230 tuner and its design doesn't require a counterpoise. Fed at the center of the horizontal leg it is a cloud burner, giving good results for short distances due to its high angle radiation pattern. Fed at a corner, running the hot side of the auto tuner to the "vertical" (if you can call it that as a delta loop) side, it becomes more vertically polarized with a lower angle of radiation and sings quite well for much longer distances.
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Old 30-04-2013, 15:07   #52
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Re: My SSB Install Was a Breeze

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Originally Posted by Celestialsailor View Post
Bill...thanx for all your info and constructive help. What I'm not understanding is the voltage thing. I am aware of the RF energy generated but not the voltage. Could you elaborate?...CS
Here's a simplified explanation.

RF energy (power) has both voltage and current components, just like any other electrical circuit. RF is alternating current (AC) at a high frequency.

If you were to pass RF thru a purely resistive circuit, the highest peak voltage and highest peak current would occur at exactly the same time. This would be called in-phase.

However, the antennas we're talking about here are not purely resistive. They are reactive, having both capacitive and inductive reactance, causing the RF to be out-of-phase. That is, the peak RF voltage and peak RF current occur at different times. So, RF voltage peaks and RF current peaks are distributed at different points along the antenna and its feedline.

You can find in-depth information in many good electrical theory sources, and in radio "bibles" such as the ARRL Handbook. Many graduate electrical and electronics engineers, after eight years of study or so, spend their lives delving deeply into this stuff, analyzing antennas, designing antennas, etc., etc. I don't pretend to be in their league.

And, the good news is that you don't have to dig in that deep, but rather just reap the benefits of thousands of hams who have experimented with HF antennas of every conceivable type for nearly a century, and have shared and published their findings for others to emulate :-)

Bill
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Old 30-04-2013, 15:10   #53
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Re: My SSB Install Was a Breeze

Quote:
Originally Posted by deckofficer View Post
Bill as always is correct. I'm now using a delta loop at home with a SG 230 tuner and its design doesn't require a counterpoise. Fed at the center of the horizontal leg it is a cloud burner, giving good results for short distances due to its high angle radiation pattern. Fed at a corner, running the hot side of the auto tuner to the "vertical" (if you can call it that as a delta loop) side, it becomes more vertically polarized with a lower angle of radiation and sings quite well for much longer distances.
Wish you could convince my XYL that I'm "always correct" :-)

The Delta Loop is a GREAT antenna. Wish I had room for one.

Congratulations!

Bill
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Old 30-04-2013, 15:21   #54
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Re: My SSB Install Was a Breeze

When it comes to your domestic duties at home I have no idea (so the misses could be right, lol), but when it comes to RF, your the one I would seek out on the forum.

I'm now moving it from the 2nd story balcony to the roof top. Should do even better 90' off the ground and no trees or house lumber to absorb some signal. A clear 360* shot to the horizon 100+ miles away.
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Old 30-04-2013, 19:22   #55
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Re: my ssb install was a breeze

Bill,
You have more patience than I do, today at least!!!
Quote:
Originally Posted by btrayfors View Post
As a ham for over 40 years and as a professional SSB installer, I don't know whether to laugh or to cry when reading this thread.
I simply hung my head, with my palm holding my forehead, and let out a big frustrating sigh!!!



To others reading this thread, PLEASE do yourself a favor and READ what Bill wrote in this thread.....and take his words to heart!!!
Quote:
Originally Posted by btrayfors View Post
No, it's not rocket science. But there is a lot of science involved, as well as art and actual experience and practice.

Hey, anybody can hook up an SSB radio just any old way using just any old thing and, with luck, make some contacts. Especially on nets with lots of folks on frequency listening. EVEN THE WORST INSTALLATION will allow you to get thru sometimes.

How do I know this? Many thousands, nay tens of thousands of contacts with boats over many many years on the various maritime nets all around the world.

Making a few contacts proves almost nothing. Making reliable contacts when you want to in many places and times and on various bands means much more.

Haven't the time or energy to respond to all the bad info in this thread.

The most egregious...

1. tuner to backstay.....use GTO-15 wire, NOT coax; failure to do so will result in possible shock hazard and in certain attenuation of the transmitted signal;

2. length of backstay.....it doesn't matter that much. Modern tuners can tune just about any length over 23' or so. Longer lengths favor lower bands; shorter lengths favor the higher bands.

3. "dipole" ... backstay antennas are not dipoles, nor are they "one half of a dipole". A dipole is a balanced antenna. A backstay is an unbalanced, end-fed random length antenna.

4. the KISS-SSB counterpoise (I'm a dealer)....yes, it's incredibly easy to install and works fairly well. It's not the best RF ground or radial system you can install, but it's not bad, and will help to tune on all bands.

FWIW,

Bill
WA6CCA

BTW, Capt Don has it just about right! Guess some folks do learn from the reading :-)
B.




Re: radiation pattern, you can't do much about horizontal patterns. They are what they are, they differ with each boat, and are largely a function of the standing rigging, mast(s), etc. However, vertical dipoles rigged low (with the lower end close to the deck) have a very low vertical angle of radiation which is why they are such great antennas for DX. A vertical dipole will put most of its radiated energy just a few degrees above the horizon, which is what you want for DX.






Here's a simplified explanation.

RF energy (power) has both voltage and current components, just like any other electrical circuit. RF is alternating current (AC) at a high frequency.

If you were to pass RF thru a purely resistive circuit, the highest peak voltage and highest peak current would occur at exactly the same time. This would be called in-phase.

However, the antennas we're talking about here are not purely resistive. They are reactive, having both capacitive and inductive reactance, causing the RF to be out-of-phase. That is, the peak RF voltage and peak RF current occur at different times. So, RF voltage peaks and RF current peaks are distributed at different points along the antenna and its feedline.

You can find in-depth information in many good electrical theory sources, and in radio "bibles" such as the ARRL Handbook. Many graduate electrical and electronics engineers, after eight years of study or so, spend their lives delving deeply into this stuff, analyzing antennas, designing antennas, etc., etc. I don't pretend to be in their league.

And, the good news is that you don't have to dig in that deep, but rather just reap the benefits of thousands of hams who have experimented with HF antennas of every conceivable type for nearly a century, and have shared and published their findings for others to emulate :-)

Bill
WA6CCA



Fair winds to all!!

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Old 01-05-2013, 05:58   #56
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I'm on a passage and just got into 4g coverage 5 miles offshore. I'm sitting on the head laughing at a multipage radio thread.

Regarding the coax, I'm just using the inner wire, the shield isn't touching anything. And I made this thread not to say what people should do but rather what I hobbled together in banderas bay and made work.

I'm going to start an anchoring thread now.
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Old 01-05-2013, 08:00   #57
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Re: My SSB Install Was a Breeze

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Originally Posted by rebel heart View Post
I'm on a passage and just got into 4g coverage 5 miles offshore. I'm sitting on the head laughing at a multipage radio thread.

Regarding the coax, I'm just using the inner wire, the shield isn't touching anything. And I made this thread not to say what people should do but rather what I hobbled together in banderas bay and made work.

I'm going to start an anchoring thread now.
Hi Eric...Glad to here everything (radio-wise) is working for you. I was also entertained with the amount of people "shivering in their timbers", over the topic. My set-up is the same as yours and with similar results. There are probably dozens of way to set up a rig if one is open-minded and wants to pursue them. Myself, I have many boat projects and once one project is complete, I move onto the next. This week is compartmentalizing the lazarette's for more stowage...It never ends does it...
P.S. I think on my next boat, I will have 200ft. of GTO 15 shackled to a Rocna anchor on my Cat with a lug-rig ketch protected by an AR15...
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Old 01-05-2013, 08:42   #58
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Re: My SSB Install Was a Breeze

Now that we have found the headwaters of the Nile, thru alchemy, voodoo, and shouting louder than other posters . . . . .

I think I read over 1000 posts before doing my own install, and a few books. I also drove over to Icom in Bellevue to question them. Although many said the KISS would not work, it does, and does well. Perhaps I did not earn the right to a good signal as I did not spend three weekends crawling in the bilge with copper foil?

One feature to consider is a separate power supply. I have a 24v house bank, and thought it easier to simply have a designated battery to power the 12v Icom 802. No noise, and no interference with the autopilot.
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Old 01-05-2013, 09:03   #59
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Re: My SSB Install Was a Breeze

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Originally Posted by rebel heart View Post
I'm on a passage and just got into 4g coverage 5 miles offshore. I'm sitting on the head laughing at a multipage radio thread.

Regarding the coax, I'm just using the inner wire, the shield isn't touching anything. And I made this thread not to say what people should do but rather what I hobbled together in banderas bay and made work.

I'm going to start an anchoring thread now.
Let's face it Eric, it isn't the subject material, its you. Remember this thread you started? The Advantages of Being a 100 Ton Captain

I outed myself for the 1st time on it. lol
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Old 03-05-2013, 10:11   #60
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Technical clarification: Special case of LONG feed line

I would like a clarification of a purely technical point regarding Tuner to Antenna connection when the feed line is unusually long.

I am considering placing my Antenna Tuner far away from the Antenna base (physical installation constraints). So, I found a 2008 post from forum member "Fairbank56" where he addressed precisely this situation:

Quote: "Most manual tuners either have a balanced output or coaxial output or both. On a boat, placing the tuner near the radio, we would use coaxial cable to feed the antenna, connecting the center conductor to the backstay lead-in wire and the shield to the ground plane. In this case, the coax does NOT radiate the signal. The signal travels between the center conductor and the inside surface of the shield til it gets to the feed point. Some of the signal can then travel back down the outside of the shield which can be radiated. To prevent this we would use a choke balun in the form of ferrite beads or several turns of the coax onto a cylindrycal form whose diameter is several inches." End quote.

Earlier in that thread he also cautions about high voltage nodes and possible damage to the coax. I am not sure how that relates to the above quotation.

Where do we locate the choke balun - at which end? I assume you must use ultra heavy duty coax?

And any expert opinions - will the proposal work; i.e. will signal loss be minimized and antenna radiation maximized by this type of feed line?
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