HF Whip antenna for a sailing yacht?!

Discussion in 'General Technical Questions and Answers' started by KJ4CRY, May 11, 2008.

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  1. KJ4CRY

    KJ4CRY Ham Member QRZ Page

    I am new to HAM and want to operate an IC 706 with AT 180 on my 50' saling sloop.
    What would be the best antenna to warrant long distance reception? Anybody ou there with experience?
    Last edited: May 11, 2008
  2. AD5ND

    AD5ND Ham Member QRZ Page

    If the mast is aluminum. You might be able to disconnect the ground and feed it there.
  3. K5END

    K5END Ham Member QRZ Page

    The best method would depend on how your sloop is rigged and the material of the masts. At least you won't have to worry about tall buildings or the landscape. :cool:

    I've heard of insulated stays used as a sloper or inverted V, and they say it works pretty well if done right. You could have different stays tuned for various bands as long as they are sufficiently separated from each other.

    If you're rigged as a yawl, the mizzen, with some radials added, could work as a monopole. I've heard that has been done, but never have seen it. That may work for a ketch also, but it may be too close to the main.

    edit added. by the way, there is a group or website, or two, or three, for land lubbers and blue-water sailors to get together & set up appointment contacts, for several obvious reasons. i'll ask my sailing-ham friends and get back with you. surely someone on the forum knows how to do this.
    Last edited: May 11, 2008
  4. KW7RF

    KW7RF Ham Member QRZ Page

    Yes, Inverted V

    I would have to agree that an inverted V would be the best choice.
  5. K3WRV

    K3WRV Guest

    I've done a few of these for friends or folk who dropped into our local 15 M net in Annapolis many years ago. From experience, I cann tell you that there is no one "Cut and dried" method that both radiates well and doesn't screw up ur boat speed (think 10 M groundplane on top of the mast) or get in the way of something. Feeding the backstay sometimes works, but running the feedline can be a pain. Feeding the backstay and the jibstay as an inverted OCF v also works, but you'll need to insulate things or run a "pseudo gamma match" which sometimes interferes with the sails going up and down.

    If you're new to ham radio, try building some antennas on land and see how they work before trying it on a boat. Buy an antenna analyzer (or at least a grid dipmeter) and get ready to play with antennas rather than sail for a Summer. You WILL get it figured out, and you'll learn a lot in the process, but itr won't be easy!

    One hint that often worked, is to run a length of coax around the inside of the hull, right at the wterline, and bond everything to it - keel, engine block, and whatever else there is.

    In full disclosure - I set one guy up for a "round the woreld" trip, and have never heard from him since!

    de Bob
    Last edited by a moderator: May 11, 2008
  6. KA4DPO

    KA4DPO Platinum Subscriber Platinum Subscriber QRZ Page

    A couple of things here. First, you can certainly use the 706 on your boat but it won't last. I know a lot of guys who used regular HF rigs on their boats and evetually the salt air will take it's toll. Get a marine rig if you wan't reliable operation.

    Next, the best maritime antenna for any sailboat (in my experience is a backstay antenna from the main mast to a point on the stern or backstay. you will of course need a different tuner and the AH4 is perfect for this application and the price won't hurt your wallet.

    Whatever you do, don't unground the mast.....Ever...
  7. N3EF

    N3EF Ham Member QRZ Page

    Check over on the Seven Seas Cruising Association web site on their communications discussion board. Here's a quote from someone on there, Bill Trayfors WA6CCA, who has a lot of experience testing different antenna configurations on sailboats:

    "Antenna System. The most effective long distance antenna you can put aboard your sailboat is a vertical dipole. In it’s elementary form, this is a single band antenna which is completely self-contained and doesn’t require any sort of external RF ground or counterpoise. That’s right: you don’t need to put 100sq feet of copper in your bilge, connect all the tanks together, hook up to your lead keel or through hulls, or any of that stuff. Just construct a robust dipole, tune it for the intended band, and you’re good to go. Dipoles can be built for pennies, using any available wire. However, real seagoing dipoles which will stand up to anything the marine environment can throw at them will cost a bit more. I use 1/8" insulated stainless steel lifeline and a special molded center insulator. You can build a dipole for 20 meters for under $35 (about $25 for 35' of lifeline and $8 for the insulator, plus a bit for the Nicopress sleeves). See construction details here:

    Why spend $35 to build such a rugged antenna when you can build a dipole for $5? Because the marinized dipole will last at least 10-15 years, while the cheaper one might not last until next week.

    OK, a 20m dipole will see you across oceans. You can sit in Tahiti or in the Med and communicate with stations Stateside. But, there is value in being able to use other bands as well, so what about that?

    You can build additional dipoles for some other bands, depending on the size of your boat. A 40m dipole will wind up being about 65' long, and most boats couldn’t hoist one as a vertical antenna. You could use it as an inverted vee however, or as an “L” antenna.

    You could also build an “alternate backstay” antenna, using the same s/s lifeline. Treat this like a regular insulated backstay antenna. You’ll now need two more things: a tuner, and an RF ground system. The tuner can be manual to cut costs, but this won’t be as efficient or as easy to use as a fully automatic one. The RF ground system could be as simple as using your aluminum toerails or the s/s pulpit/pushpit/lifeline complex, or radial wires strung under the decks. Or, you could go the more traditional route and build an RF ground system coupled to the seawater.

    All this can be done incrementally, as you need to. But a simple transceiver and vertical dipole will work great, and even after you have a more complex, expensive, and versatile system aboard the dipole will likely continue to do the heavy lifting."

    Link to communications discussion board

    Eric N3EF
  8. K1VSK

    K1VSK Ham Member QRZ Page

    This guy who continually argues in favor of vertical dipoles makes me wonder if he ever really cruised - when i discussed this with him, he sounded quite oblivious to the practical aspects of antenna construction and boat management.

    The vertical dipole is certainly one option but not necessarily practical or useful on more than it's resonant frequency. Consequently, I'd put that option at the bottom of my list as it's only really useful to the dock-bound boater community.

    Over the years, we have used just about every conceivable antenna on our sloop, a pic of which you can see by looking me up here on qrz.com. Among the most effective and practical are the ubiquitous end-fed insulated backstay and the stand-alone whip. As you q pertains to the latter category, my experience is limited to the Icom AH-4 whip/tuner combination which worked well for over 10 years of cruising. The only objection we ever had which was the reason for going from it to the backstay was the humming wind generated noise we could never mitigate.

    Either antenna will work well and my IC735 has survived 17,000 cruising miles so be leary of anyone who advocates the use of so-called marine radios.

    Have fun with the RF field generated effects onboard and the ground loops.
  9. W7GIB

    W7GIB Ham Member QRZ Page

    I spent many years in the Navy and we used verticle Whip antennaes on 65 foot patrol boats for HF work. Mark III Patrol boats for anybody who is curious.

    The Idea of UNGROUNDING the mast is not only silly, but very dangerous. Think very large rod and fur trick.

    Luckily being a sail boat, you actually have a naturally high point to work with, complete with rigging to get you to the top safely.

    Good Luck.
  10. KA4DPO

    KA4DPO Platinum Subscriber Platinum Subscriber QRZ Page

    If your IC-735 has lasted that long consider yourself lucky. Several friends of mine in Florida tried to run ham rigs and none of them lasted more than a year and a half before corrosion began to cause problems.

    I'm not advocating a marine radio but I am suggesting it since they are built for that environment. All of the newer marine rigs will operate in the ham bands, granted programming can be a pain on some of them. I never had any RF problems and only used the engine and a copper strip in the quadrant compartment as my ground.

    By the way, I saw the picture of your boat. She's a beauty.
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