Hi, new guy here.
I'm contemplating operating from a sail boat and was wondering if and hoping for some folks experienced in Marine HF operations. Especially in the antenna department. I'm half tempted to hoist a vertical and use the water as my radial component, but I'm really interested in hearing what's worked, what's not worked so well and what's just not to be expected in a marine environment. So far my most exotic marine operation has been vhf. Very Vanilla.
Thanks much.
There's a lot of people operating "maritime mobile". Google around and you'll find lots of info. I think most sailors insulate those front-back cables holding up the mast and use them as the antenna.
Listen in to 14.300MHz and look up www.14300.net (http://www.14300.net/) on the web. It's a daily maritime net.
If I had a sail boat I would absolutely have HF on the boat so I could talk to people while I was "going nowhere slowly at great expense". ::)
I am very interested in the subject as well, having recently bought a set of drawings to build a 13ft. boat designed by John Welsford, called a Fafnir: http://www.duckworksmagazine.com/08/designs/fafnir/index.htm (http://www.duckworksmagazine.com/08/designs/fafnir/index.htm) A friend of mine is digitizing the plans right now and should be sending me cutting files soon. I absolutely want HF on board, at least 20m. My mast will be free-standing. Welsford has a Chinese lug sail plan for it, which I have.. So the mast is wooden. There is no rigging. It is about 16ft. above deck.
My issue is twofold: The short length of the mast and lightning protection. A wire could be run inside the mast but in case of lightning, the mast explodes.. Even run on the mast surface, lightning would probably destroy the mast, but why risk it? I think it would be better to hoist a wire antenna when needed.. I love end-feds, but they are supposed to be a half-wave long.. Maybe with a coil at the bottom..? Maybe with a trap it would be possible to make a 20/40 reduce-length end-fed?
Another solution I have seen proposed for boats is a loop which goes from inside the cabin to the bow, then top of the mast, stern and back inside.. For a larger boat, I would run an end-fed from the top of the mast to the stern.
I also thought about the Buddistick.. It would need to be reinforced but would probably work fine with all that salt water around.
A whole aluminum mast could be used with an end-fed matching box if the rigging could be isolated or not made of metal..
For lower bands a kite might be a good idea..
I am curious as to what other ideas might be posted here though :)
Gil.
Having lived over a thousand miles from the nearest ocean my entire life, I'll have to defer the question to the members on here with sailing experience ;D . I will say welcome to the forum though.
The most common arrangement I've seen is the back stay antenna whereby one isolates and uses the backstay itself or runs an antenna further aft of the backstay on a stern spar of some kind. Which seems sub optimal to me since thats going to require a good deal of tuning especially on the lower bands. A windom would be nice but 147' of the long side means I'd have to aquire a very very large boat to make that fit. (not that I'd complain) My terrestrial windom ocf is a longstanding favorite. But it seems to me with the exceptional grounding a vertical of some kind might be a higher performer with a lower angle of radiation.... But I've not found good testimony to back that theory.
Lightning and masts.... Just keep out from underneath ominous clouds(?)
If the boat had a wooden mast, I would instal hamsticks with a counter poise. For sailboats the most common HF antenna is using the backstay to support a 40meter wire vertical or a 20meter dipole. A friend of mine is sailing from Mexico to Tahiti and this is what he uses.
73'S KA5SIW
Quote from: WillieNelsonMandella on January 15, 2014, 03:43:18 PM
Hi, new guy here.
I'm contemplating operating from a sail boat and was wondering if and hoping for some folks experienced in Marine HF operations. Especially in the antenna department. I'm half tempted to hoist a vertical and use the water as my radial component, but I'm really interested in hearing what's worked, what's not worked so well and what's just not to be expected in a marine environment. So far my most exotic marine operation has been vhf. Very Vanilla.
Thanks much.
One thing to consider for the counterpoise is that water doesn't really make a good one unless its salt water - fresh water has very little conductance if any at all ! But for the antenna, us a wire backstay and feed it with one of the autotuners from SGC like the SG-237. WIth a 28' wire you can work 6 thru 160 meters with the SG-237 but is also needs a good counterpoise like the metal hull of a boat or at least a copper or brass keel strip or even a wire ran around the perimeter of the gunwale.
Shakespere made boat antenna's at one time, but i would imagine that they were mainly designed for the marine bands.
I would imagine that it would take a pretty long wire antenna to transmit on 160 meters and have someone hear you, or be able to receive much on 160 meters with a short wire antenna.
There are antenna designs that takes advantage of using smaller loops - one looks much like a spider web while others are diamond shaped called a Fan Dipole. There are designs for both in back issues of QST Magazine.
WillieNelsonMandella (love the name)
I lived aboard for about 5 years and I operated HF a few different ways.
1. My QUICK set-up was: When on the hook or at my home marina I just ran a wire up the mast from astern using any available halyard. "ground" was usually the grounding strap for the engine block that ran straight to the big, lead keel. Because of the mains'l boom movement, I could not sail like this.
2. I made a 3-4 foot stainless tubing extension to the starboard, aft railing. It had a home made insulator in it. Using a SPARE halyard I was able to haul the antenna wire up AND clear the mains'l . "Grounds" were constantly experimented with, none were great but again, the engine block to lead keel was the most successful when augmented with counterpoise wires of various lengths run below the cabin sole.
3. My last boat, I just decided to do it right and installed two Norseman "replaceable" insulators into the back stay and 'ground' was as usual. This worked very well down to about 5 MHz, and was usable, though not efficient, all the way down to 2182 USB calling freq with the antenna coupler that was mounted below decks, right at the stay plate. I ran e-mail over radio, HF voice and CW with NO RF PROBLEMS at all with this set-up. Naturally, this worked fine whether the boat was at rest or sailing.
This was our home -
(http://www.cruisedealss.com/wp-content/uploads/2013/02/1988-bayfield-32c-1.jpg)
You can imagine how much RUM it took to sail her THAT far up onto dry land!!! ha ha
de RadioRay ..._ ._
more pics after she was cleaned-out for sale. :'(
http://www.boats.com/listing/gallery.jsp?entityid=120951011&mid=1127&ceid=216294&galleryBack=%2Fboat-details%2FBayfield-32C%2F120951011%3Fr%3D120951011%26entityid%3D120951011&pic=5 (http://www.boats.com/listing/gallery.jsp?entityid=120951011&mid=1127&ceid=216294&galleryBack=%2Fboat-details%2FBayfield-32C%2F120951011%3Fr%3D120951011%26entityid%3D120951011&pic=5)
Thanks RR! That's exactly the kind of 'been there done that' I was looking for.
My primary concern was winlink. Sounds like you nailed it more or less (more than less). I'm moored in brackish but spend most of my sail time in salt, and was curious about the grounding. But it sounds like the engine is going to be the better bet. I was imagining zincs or something even more elaborate. Let's see... now just google Norseman insulators...
Providence is a beauty!
PS, I've been running your clock for contacts in the field off and on for five or so years now; It's how my family finds each other on HF. It's nice to finally meet the man himself.
WNMdella-
Ha! To tell you the truth, the brackish thing is what we have up here on the Chesapeake Bay,. depending upon whether you're near the entrance or up one of the creeks. The same applies the further north/UP you go, away from the sea and toward the large Susquehanna River. The key for me was to think of -surface area- in contact with the water as well as just having as much 'counterpoise' as possible for your 'ground'. Because radio frequency energy runs along the surface of the conductor, grounding is best with copper strapping, or wide coax type braid & etc. I'd even occasionally toss a 'grounded' piece over the stern rail for very good drain of RF - THEN I began to think about electrolysis... I never reached a final decision about that last part. I ran PACTOR III aboard even my first boat from day one, using my manpack set-up! ha ha
Glad to hear that the calling clock idea has worked for you. That makes me smile, to know that I've helped someone who is out there doing it. I loved being out on the hook with nothing electronic running except the ham station. It was AMAZING what you can hear with NO local electrical noise! Reminded me of being up in the Rockies or in the wilderness in Idaho.
If you are ever on the Chesapeake, PM me and we'll swap lies
(http://torontosportsmedia.com/wp-content/uploads/2013/05/BS-Detector.jpg)
oh, I mean TRUE Tales of The Sea.
de RadioRay ..._ ._
Ps. I don't know whether you're a CW addict of not, but shore station KSM - Bolinas California (formerly KPH) STILL takes CW radiogrammes over the air for FREE delivery on Saturdays. You can easily get the morse/narrow band direct printing endorsement on your marine license for free. It's fun to do it 'the old way too.
www.radiomarine.org
Quote from: RadioRay on January 22, 2014, 06:03:23 PMor up one of the creeks.
I seem to spend a lot of time up a creek. But, sadly, I don't own a boat.
Wally
We lived on our Luger 30' home built kit boat for 6 years. When it came time to instal a marine SSB, this is what I came up with from the sailing magazines and trial and error.
We ended up using a aft mounted whip around 25' tall. The antenna tuner was mounted directly under the antenna as close as possible per radio manufacturers instructions. The tuner was accessible from the aft berth.
All metal deck fittings, winches, mast, engine etc was bonded with #6 battery cable to a through hull ground made of a copper or bronze sponge like material.
The radio and tuner were also grounded to this using 2" wide copper strap. This metal sponge, engine prop shaft and 14" 4 blade prop gave a pretty good size ground exposure to the sea water. Grounding surface area is critical for good radio performance said all articles I read.
This configuration worked well. At the time, the whip antenna cost less than the back stay insulators, necessary for using the back stay as an antenna.
One thing I would change is to use conductive corrosion preventing grease on all grounding connections. Over time the connections started to go bad and needed cleaning up.
This was all 20 years ago so I may have forgotten something by now.
Good sailing and good luck to you.
QuoteWe ended up using a aft mounted whip around 25' tall.
What kind of whip Mike?
Gil.
It was an antenna sold by West Marine. I can't remember the brand name, but I do remember it was a well known marine electronics company or a well known antenna company. It's been too many years. I know the label is gone from the antenna because grabbing it bare handed will give you a hand full of fiberglass. I need to varnish it.
There was an HF marine whip made by Shakespeare and here is one example. They were usually on power boats, but I did see one sailboat that had one on her stern. Should have named her the 'Scorpion"! ha ha
de Ray
I used to have a Shakespeare CB antenna in the early 80s on my parent's house. It's still there! So i know they last! It has wethered countless storms and high winds fo thirty years.
Gil.
Quote from: gil on January 25, 2014, 01:38:54 AM
QuoteWe ended up using a aft mounted whip around 25' tall.
What kind of whip Mike?
Gil.
Gil, and anyone else interested,
You might want to take a look at the Eagle One Vertical at www.w8afx.com Its a 31' fiberglass telescopic whip that works well as a permanent mounted or portable antenna that collapses down to 44 inches when not in use. Alone it is self resonant on 40 meters being a quarter wave but I use mine with an Icom AH4 autotuner at the feedpoint for 10 thru 80 meter operations and yes it does work fairly well on 80 !
QuoteGil, and anyone else interested,
You might want to take a look at the Eagle One Vertical at www.w8afx.com
Thanks, interesting. It could definitely be useful on a boat!
Gil.
Truthfully, having been in more than a few gales/storms ina sailboat, I would not use a whip. Boat motion in a rough sea must be experienced to be believed! Having the boat pushed through >90 degrees of motion on all axis in a VERY short period of time puts tremendous stress on anything not bolted to the boat at both ends - including crew.
(http://i1.ytimg.com/vi/KhMjlcE_UxQ/hqdefault.jpg)
The motion arm of a looooong whip (which is also a compromise antenna on many bands) exerts tremendous force. The backstay antenna is used because it has a proven record of survivability and adequate efficiency. Think of torque on the mount of a 25-30 foot whip with that much moment arm... Even in a calm sea, it's work hardening the metal and one day SNIP!
MY 0.02 cents worth - Please correct for inflation,
>Ray
That makes sense Ray. I was thinking or a removable whip, but problem is, you might need to radio especially in a storm!
The problem with my project (see attached photo) is that the mast is unstayed. It's about 15ft above deck. Boat is 13ft long, all wood. I can hoist a wire up the mast, or have one inside or against the mast, but it's still only 15ft, 16 at the most. I don't like the idea of a lightning rod on a 13ft wooden boat... There doesn't seem to be an easy option there...
Gil.
If I did this correctly, the link below has a pic of my transom with part of the bottom section of my whip. It mounts to the top of the transom and to the stern rail. We have been knocked down, beat up in all kinds of weather and all day long in sickening waves from all directions.
Go to the second page, top pic. This will give you an idea of the size of these antennas.
http://www.natconet.com/~mdmc/Personal1/index1.html (http://www.natconet.com/~mdmc/Personal1/index1.html)
Shakespear used to make a 2section CB dipole vertical. That antenna could be used on 15 meters tuned with a tuner. I used one back in my novice days.
73'S KA5SIW
I would say that a Magnetic loop antenna would work well. It is small enough and it can be mounted horizontally (up high) for omni-directional use and vertically (can be on the deck) for directional use. Up high and horizontal puts you inside of a null. This is nice for reducing EMI. Usually these antennas do not need radial grounds.
You probably should carry a set of dipole wires and a balun as a backup or for coverage in bands not covered by a mag loop.
Good grounding of the radio, tuners, and the power supply is important. This is hard to come by in a sailboat.
Oh, I forgot to mention something else of entertainment value. Watch the movie All is Lost. It is a great sailing movie. A radio is featured in this movie. The sailor does some pretty boneheaded things in the movie.
Luigi