# SSB antenna



## Omatako (Sep 14, 2003)

Hi guys

I am soon going to be collecting a boat from California and sailing it to New Zealand. The boat doesn't have an SSB (has a Global Star phone) and consequently doesn't have an antenna incorporated into the backstay or any form of ground plane (Dynaplate). I also won't have the time between arriving in the US and leaving for NZ to have the required mods done to the backstay oir absence of ground plane(too much other stuff to do).

Has anybody had any experience with whip antennea for SSB and their effectiveness for long range communication?

I've sort of established that there is a combination of radio, antenna tuner and 16 foot whip antenna that produces results. The question obviously is: How good are those results. . . . really. . . . not dealer opinion.

Any ideas (or even better, actual experience) out there? And given that I know squat from radios, let's try and keep this down to single syllables please. 

Cheers
Andre


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## sailingdog (Mar 19, 2006)

While you don't say what the boat is, there are other ways to setup an antenna and ground plane for SSB. If the boat has a metal hull or large metal tanks down below, for fuel and water, you can often use those to create a large ground plane fairly quickly. 

There are also antenna designs that do not require a ground plane.


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## Bill Mc (Apr 10, 2006)

*Antenna's*

Try this for an antenna. Gam Antennas If you are just doing a delivery you can take it with you when your done.

Fair Winds,

Bill


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## btrayfors (Aug 25, 2006)

Omatako,

It would be easier to answer your query if you had mentioned the type/size of boat and whether you're talking about ham SSB or marine SSB or both.

The easiest way to put a HF/SSB rig on the air with RELIABLE long-distance communication is to construct one or more vertical dipole antennas. See my posts on constructing a marine dipole: Gallery :: Constructing a Marine Dipole Antenna

and on tuning a marine dipole antenna:

SSCA Discussion Board :: View topic - How to Tune a Marine Dipole Antenna

A vertical dipole antenna will outperform any other seagoing antenna you can put on a sailboat. Period. They are, however, limited to single-band operation for transmitting; they receive well on all bands.

For many years when chartering, I carried a small HF transceiver with big alligator clips on the power cord, and a dipole antenna. It took only a few minutes after stepping aboard to be QRV (ready) to transmit on the ham bands, and to talk with friends around the world.

Good luck on your delivery.

Bill
WA6CCA
S/V Born Free


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## TSOJOURNER (Dec 16, 1999)

*Inverted V*

I was thinking of using an inverted V antenna using a wire cored halyard. Over the top of the mast either abeam or length wise.

I want to install some of my ham gear on my boat as well. There a several installation options and what makes me think the most is the termination of the coaxial connection section of the antenna to a point where it will be easy to hook to the back of the radio. The most obvious that comes to mind is to create a termination block on the cabin top above the nav station, with strain relief for the antenna halyard, and cover it when the antenna is disconnected.

I know for your case you might just want to just run the cable through the companionway to the radio and not modify the cabin top.

Just my 1/2 cents worth...


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## Omatako (Sep 14, 2003)

Hi guys

The boat is a Morgan 44 GRP, sloop, what more can I add? The radio I was thinking of is an Icom IC-M700 or something like that. It'll not be HAM, just marine SSB. Unfortunatley I have no idea what tanks etc. are fitted. Believe it or not I haven't seen the boat in the flesh yet. On my previous boat I had a Kenwood, can't remember the model, with an antenna tuner and it worked a treat on the backstay with no real ground plane to speak of. I spoke to South Africa and Australia from Maldives with pretty clear voice.

Bill Mc
The GAM thing looks pretty good to install in a hurry and then make it more permanent when I get the boat home. Oh, and it's not a delivery, I am buying the boat for myself. I'll get a hold of those guys and have a yarn with them. Thanks for the link.

Btrayfors (Bill)
Can an antenna like this be used with a tuner? If the dipole is cut for a certain frequency then (to me) that's no different to a backstay which is fixed length. If a tuner is used with this, is it fair to believe that more than one frequency can be transmitted? And how would one install one of these on a boat? I guess the two legs of the dipole need to be running in opposite directions so it seems this setup would take up some space.

I also have seen catamarans with long whips (16 feet) on the back of the boat and this is why I figured this may be the easiest way. I'm just not sure about range for transmitting. There'll be times when I'm going to be a heck of a long way from anybody else but HF really doesn't care about that does it?

You guys can probably tell by now that I don't know a whole lot about these things.

Thanks for info so far.
Andre


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## SimonV (Jul 6, 2006)

Andre.

Your not on your own there with HF/SSB/HAM, my question is does the GAM antenna need to go on the back stay could it go on one of the side stays. I have seen these automatic antenna tuners for @$450us, I take it, they will adjust the length or the antenna internaly ! the radio is $999us.


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## mandovai (Nov 28, 2006)

If you want to do it fast and cheap, just put a linear electric cable with two plastic isolators that reaches the tuner, if you have one, Not the best performance, but fast and simple! You rig it with an halyard when you need it or you mount it permanently on the mast. Mine is mounted on the spi halyard and comes down close to the shrouds. Works ok allround. 
good luck


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## btrayfors (Aug 25, 2006)

Andre,

OK. With the additional info you provided (boat size, it's YOUR boat, the M700 and tuner, your interest is in the marine bands, not ham, etc.), here are some options:

(1) Most versatile. Install either a Gam antenna (I can't believe I'm saying this) or, better, an "alternate backstay" antenna consisting of a length of insulated s/s lifeline at least 23' long. This can be hoisted with a spare halyard, and the lower end tied off to one side of the pushpit. With either option, locate the tuner under the deck as close to the base of the antenna as possible. With both options you need a good RF ground. Easiest of all, but not very efficient: run a wide copper strap from the tuner to the nearest bronze thru-hull. To increase efficiency, add radials under the deck (insulated wire, any size, the more the better). A couple of 1/4 wave radials (length in feet = 234/Freq in mHz) for each desired band would be sufficient. 

(2) Most efficient for long-distance communications -- one or two vertical dipole antennas, constructed according to data referenced in the links I provided above. This is an extremely effective long-distance antenna. A vertical dipole is best rigged forward of the mast, about halfway between the mast and the forestay, tied off to a toerail. This placement works well when at anchor, in a marina, or when under power. When sailing, it's only necessary to undo the lower end of the dipole and pull it back into the shrouds. It will work fine there, but with a bit less efficiency. The coax feedline should be run off at a right angle, or as close to that as can be easily done. Usually, this means running it back to the mast high above the deck, then down the mast to the rig. On my boat, I've fitted a little custom-built "black box" attached just below the gooseneck, which contains connections for the coax and which is permanent. You may find it easier to feed the coax thru a deck ventilator, or a hatch or a s/s coax deck fitting or anything handy.

The dipole is a single-band only antenna. When tuned, it does not require a separate tuner...attaches direct to the radio. While it is possible with a tuner to transmit on additional bands, this is not a good idea and is very inefficient.

If I were making the trip you contemplate, I'd choose both: a versatile backstay antenna with tuner and good RF ground system which could be used on any frequency, and vertical dipoles for 14mHz (MM net) and 21mHz (Pacific Maritime Net) ham bands for really efficient long-distance communication. If you are not a ham or there's no ham aboard you can listen to these nets which have a wealth of information and, in an emergency, you could use them to seek help. For the trip you're about to take, ham radio is much more useful than marine SSB, IMHO.

Re: verticals, they can be very effective. However, for a very long ocean voyage I wouldn't want a 23' vertical (or even a 16' vertical) whipping around back there in a seaway. Not a good idea, IMO. They do make good emergency antennas, though, in case you lose your mast. I have a Hustler mobile antenna mounted on my pushpit and wired to an antenna switch near the rig. I carry the mast and resonators for several bands below, ready to deploy in an emergency.

Bill
WA6CCA


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## Omatako (Sep 14, 2003)

Btrayfors

The dipole seems to be (with great respect to the design and your recommendation) a bit messy with wires all over the place. It is also my belief FWIW that you're going to need this radio thingy most when there's 80 knots across the deck and all hell is breaking loose. So the prospect of loose wires in the rig and on the mast and running through hatches that as a result don't really close (remember this is a temporary fitting for one trip only) runs deeply counter to my fetish for neat and tidy.

I'll be more comfortable with the GAM pasted onto the backstay for this trip which by the sounds of your comment will probably give me reasonably good performance across all the bands. I did understand that correctly, didn't I? I am not a ham and SWMBO knows only about ham that goes between slices of bread so those other freqencies you mention are probably of no value to me.

And in your opinion, is the Icom M700 with a suitable tuner satisfactory for this type of setup?

SimonV, what radio are you recommending at $900? A new IC M700 costs about $1900. Your estimate on the tuner is about what the dealer I spoke to came up with. And while I'm on the cost of the radio, who knows of a good used-radio dealer in the San Diego area that may have a good and reliable used unit for sale? 

Please keep in mind that when I get to the US, I have two weeks to prepare a boat that I am seeing for the very first time when I arrive, for the voyage. This is very definitely not just about radios!! I need something that finds the best balance between speed of installation, reliability and performance. Gam starts to sound better each time I say it .

Thanks so far
Andre


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## SimonV (Jul 6, 2006)

I have been looking around on the net in the states not knowing what I want or need the ICOM IC-M700 Is available on line for $900 + postage and the m710 for $1300 all us$ you have to search I found these on EBAY store from one of the outlets you have to work through them, they were advertising a second hand unit I cant remember what radio and it popped up on their web page. Something else they stated was that due to the large number of requests for different channels, ICOM was now supplying the units with all channels installed. 
Now my question. Automatic antenna tuners do you need them? 

I too will be getting a boat from the states in the next 18mths.

WEST MARINE (the robbers) advertise on line the M700 for $1099.


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## SimonV (Jul 6, 2006)

Andre
You’re not giving your self much time to prepare. What I have been told is if you need to do work on the boat on the hard, not many yards let you do the work yourself and its very expensive. It was recommended to me, do as much of your work in Mexico its less then half the cost, and the workmanship is better!!.


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## btrayfors (Aug 25, 2006)

Guys,

You're talking about the Icom M700 PRO, not the M700 which is a much older rig that was the standard for awhile. It sells used for about $400-600, but doesn't have the flexibility of the newer rigs.

Yes, you need a tuner. No practical way around that. Figure another $300-500.

And, if you're going to use an end-fed antenna like a backstay or alternate backstay, you'll need a good RF ground system as well.

Andre....I, too, think you've got far too little time to prepare a new-to-you boat for a 10,000 mile trip. The radio will be the least of your worries.

Bill


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## Omatako (Sep 14, 2003)

Thanks for the concern about my preparation guys but the vessel was taken out in August last year coincidentally in Mexico and the bottom was painted and antifouled, through hulls serviced and a new prop fitted. One would assume they wouldn't not fix things like cutlass bearings etc while it was out. OK that is a little while ago but the underside should still be OK. In any case the boat is undergoing a full survey (hull, engine and rig) so I guess that'll tell it all. The way I see it is if I got a professional delivery done, the person doing it wouldn't sit around waiting for a month while repairs are done to his satisfaction. You check the critical systems are OK and the rest you live with. This is not a holiday voyage, it's a "delivery" voyage. A straight dash for home.

Whilst I haven't done any research yet, I'm astonished that the dealer I went to on-line has a price of $1900 and you guys are getting prices of half that. Seems I need to do some work. Thanks for the heads-up on that one.

And by the way, unless NZ has moved recently, it's only 6000 miles (rhumb line)


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## sailingdog (Mar 19, 2006)

I think bill's estimate of 10,000 miles is far more accurate... the chance of you being able to sail a straight rhumb line course, without deviating is about zero. Given the fact that a sailboat has serious limitations in the directions in which it can go, determined by the wind... estimating that it will take the boat 10,000 miles of actual travel to move 6,000 as the crow flies is actually rather optimistic IMHO.


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## Omatako (Sep 14, 2003)

I reckon on this one we'll have to agree to disagree.

All of the reports that I have read of people doing trips from Panama and the US westwards across the Pacific (and I've read pretty much everything that I could find) indicate that the voyages they did in total distance, supported by the time it took them to cover the distances of the assorted legs didn't vary much from the rhumb line distances. I've even gone to the trouble of visiting a chandler in NZ who deals in used charts that he buys from passing cruising boats. Their courses are still on many of the charts and they're about as staight a line across the ocean as you can get. And not just one lucky fellow, all of them.

Remember this is the Coconut Milk Run. This is a world of following currents that are actually invariable and trade winds that pretty much stay the way you expect them to (mostly on the beam). Yes there will be weather cells that will have you changing course for a day or two but this is not a voyage where you're beating all or even most of the way. This is a downhill run in the truest sense of the sailing world.

And the routing charts I have examined that are created from many decades of accumulated data support this contention. Whilst I don't expect to use a ruler to plot my course from one end to the other, 60% more than the rhumb line distance is just plain wrong. Sorry. 

Andre


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## sailingdog (Mar 19, 2006)

Andre-

I'm on my laptop working, and don't have VPP2 installed on this machine, since it is my work machine, not my boat machine. When I get a chance tomorrow, I'll plug in the route from San Diego to Opua... and see what it says.


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## SimonV (Jul 6, 2006)

SD
What is vpp2?


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## Omatako (Sep 14, 2003)

SD,

If it's anything like my system (Seapro) it'll probably come in at around 5890 miles (rhumb line). At least I hope so else my system is lying.
Andre


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## Bill Mc (Apr 10, 2006)

SimonV said:


> Andre.
> 
> Your not on your own there with HF/SSB/HAM, my question is does the GAM antenna need to go on the back stay could it go on one of the side stays. I have seen these automatic antenna tuners for @$450us, I take it, they will adjust the length or the antenna internaly ! the radio is $999us.


The GAM antenna can be mounted anywhere as long as it is vertical, (yes a slope is fine too.) Mine is on the back stay. My neighbor has a catamaran and has his on the port stay and keeps an extra to haul up with a halyard in case of emergency. Yes, these definitely go thru an antenna tuner..

Hope this helps.

Asking a ham about antennas will usually heat up a conversation the same way as asking a sailor what the best anchor is. 

Fair Winds,

Bill


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## do335 (Jul 27, 2003)

*Backstay Antenna Installation*

I'm preparing to convert my backstay for use as a SSB and HF antenna. I've noticed that sometimes people install the lower insulator high off the deck and run the feed from the tuner to above this insulator. Why not install the insulator lower? If you cover the antenna above the insulator with a plastic pipe you should be able to avoid any shocks.

I'm planning on using swageless fittings to convert my backstay. Any recommendation on which brands of fitting and insulators and why?

Thanks


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## sailingdog (Mar 19, 2006)

Do335-

Why do you want to cut the backstay and introduce the possibility of rigging failure due to the modification. They also make backstay antennas that are mounted in parallel to the existing backstay, that don't run these risks.

If you really must cut the backstay, I would recommend that you use the Hayn Hi-mod type swageless fittings and their insulator, since it is supposedly failsafe. 

The problem isn't really shocks, but RF-induced burns. While I don't recall the maximum distance this can happen at, IIRC, a plastic pipe isn't enough to stop it from happening. 

Also, putting a plastic pipe around your backstay is a good way to trap water against it and increase the risks of corrosion-induced failure.


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## do335 (Jul 27, 2003)

I've considered a seperate wire to the masthead but that's adding more windage and doesn't seem as reliable. A whip is possible, but has some of the same issues. I've read about the antenna that mounts next to the backstay, but no one who has used one. All HAM's I've spoken to don't believe they will work. The tubing I'm thinking of would be 1" or more in diameter. That should have enough space to allow air between the wire and tube.


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## sailingdog (Mar 19, 2006)

Ummm... Do335, _*you're worried about the windage from adding a separate wire to the masthead... but not worried about the effects of windage that adding a 1" diameter tube over the backstay.*_.. Hmmm...strikes me as flawed thinking in many ways.


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## do335 (Jul 27, 2003)

The tube only covers the backstay to a height that person could accidently touch the active section of the antenna, approx 7'. This should eliminate or reduce chance of shock when transmitting.


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## GailDixon (Feb 22, 2011)

Has anybody mounted the GAM split-lead antenna on a shroud rather than on the backstay? My Hunter 49 has no backstay!
Gaildixon


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## Brezzin (Dec 4, 2006)

Old thread but Yes. A good friend has one mounted on a port stay on his lagoon 440. He also has no backstay. The kicker is this. The GAM is 34 feet long and on our boats you will have to set it up to go around the spreader.


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## windward54 (Apr 12, 2000)

Another option I've seen on some of the Hunters was a fake backstay, which was used as the antenna. Since Hunters use a mainsail with a large roach, just have to make sure the sail will clear the fake backstay.

I usually warn people that are thinking about a GAM that there is one issue to consider. The GTO-15 feed line wicks moisture and can corrode out. The antenna then has to be taken down and sent back to the manufacturer, as this part is not replaceable by the user. If you are close to a port where this is no problem, fine. If you are doing extended cruising, something to consider. Other than that, the antenna works great.


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