December 27, 2001

Let me know how your ham installation works out. You might want to consider an insulated backstay - with proper ground and a good tuner (the SGC is one), it really works.

Dec 28, 2001

My Ham antenna consists of the port forward mizzen stay, a jumper and the triatic stay, or whatever you want to name the stay from the mizzen to main masthead. I have always gotten good signal reports. By using this combination of stays, the radiating elements are in the open, as opposed to the main backstay, which has the grounded triatic above it. I believe this rig is superior to using the main backstay. The antenna tuner (Icom) is mounted in the port cockpit locker, against the hull. The lead passes up through the deck to the mizzen stay. There is a jumper leading from the upper end of the mizzen stay to the triatic. It is held away from the head of the mizzen mast by a small strut, maybe 8 inches long. This installation requires four insulators, two at the ends of the mizzen stay and two at the ends of the triatic. Although it is not necessary, I made the antenna from a single piece of 5/32" 1 x 19 stainless wire, all the way from the mainmasthead to the deck, using nicropress fitting to attach the wire lead to the lower triatic insulator. I used nicro-press fittings to attach the lower part to the mizzen stay, in effect doubling that stay, but insuring there were no splices in the antenna from the lead-in wire to the mainmasthead. I attached the jumper to to the strut with an insulator. The insulators on the triatic are egg insulators, which might be found at a ham flea-market. Staylock insulators are used on the mizzen stay which has more stress on it. More important than the antenna rig is the grounding. In addition to engine, tank and grounding plate, I have grounded to the keel ballast by drilling and then screwing a stainless threaded rod into the ballast, all done in the originally concealed compartment beneath the mast and forward of the water tank. I think the latter is the most important part of the ground circuit.

Dec 28, 2001

If, after this sound plea for an antenna unshielded by the triatic, you still are interested in the Y back stay as antenna (if only to avoid jumper and multiple insulators), consider replacing the triatic wire (between the two mast heads) with a high tensile rope from main mast head to a block at the mizzen top and down to a cleat opposite to the mizzen sheet cleat. This should remove the shielding effect.

Jan 24, 2002

One thing I have learned using the ham radio Winlink system, is to ask my correspondents to delete the incoming message before launching their response. Sometimes, in our case, the incoming message may be necessary to maintain the continuity, but that can get out of hand and the bytes multiply.

4292

Nov 30, 2003

Why not use the triatic for the ssb antenna?

Gene Kohrman

PANACHE #60k, ASII

 

4293

Nov 30, 2003

The triatic is an excellent place for a SSB (or HAM in my case) antenna.

There is the question of where to put the antenna tuner. Some larger ketches have placed the automatic antenna tuner at the top of a mast, with one lead going to the triatic and the other (ground) going to the mast. Then coax must be led from the transceiver all the way to the masthead.

I have been using the triatic for years and get good signal reports. My antomatic antenna tuner is located in the port cockpit locker with a coax lead of 10 feet or so to the transceiver. I have insulators at the top and bottom of the port forward mizzen shroud and both ends of the triatic. The triatic is part of a continuous single 1x19 5/32" stainless rigging wire from the top of the mainmast all the way to the foot of the port forward mizzen shroud. I used nicropress sleeves to splice in an extension from this wire to the lower triatic insulator. I attached a metal strut to the top of the mizzen mast. It is directed to port and is about 10" long. The continuous antenna wire leads through an insulator attached to the end of the strut, then leads down towards the deck adjacent to the port forward mizzen
shroud. The port forward mizzen shroud and the antenna wire are held together with nicropress sleeves, 3 or 4 of them. At the lower end of the port forward mizzen shroud, just above the lower insulator, the antenna wire is spliced to a piece of automotive high voltage wire, such as used for spark plug leads. I have tried to waterproof this joint with exterior type electrical tape. It is led through the deck near the mizzen chainplate and thence to the antenna tuner. It is advantageous to keep the antenna wire distant from the mizzen mast and other grounded structures as much as possible. The length of the antenna, from the antenna tuner to the mainmast head is nice and long, an advantage. I am sure the radiation pattern is not symmetrical, but it does not seem to be a problem.

A good ground is also important for a good antenna system. I use 2" wide copper foil bonding to water tank, grounding plate, transceiver and lead keel ballast. You can access this ballast by drilling toward it in the bottom of the forward bilge. The mass of the ballast is an important positive in achieving a good ground.

Some have used the main backstay(s) for an antenna, but whether the triatic is wire or rope, that antenna has a lot of surrounding grounded structures.

Dick Weaver, SWII 75K

 

 

 

5066

Aug 14, 2004

Hi All,
A quick question: I have finally bit the bullet and bought an SSB.
Any advice on antennas? I am after both a quick and dirty solution
for right now and a good, permanent solution.
Alison and I are living in Sydney now and left True Blue in New
Caledonia for a prolonged cyclone season (and to make some money).
I am off to Noumea on Friday to get her. I will be bound for
Australia, probably Coffs, Hbr maybe Bundaberg, depending on the
weather. (The Pacific taught me one thing- don't fight the
weather). I'll be single handing so I want to keep it behind the
beam. The radio should provide a little company.
My engine is out (a perkins m30). It lost compression, so we are
putting in new rings and replacing a couple of the valves. I think
having salt water through it in the Marqueses didn't help.
I have also bought a Simrad tiller pilot to hook to my windvane when
there is no wind. I'll be motoring in the calms this time because
of work commitments. I plan to bind it to the aft railing and tie
the end of the piston to the vane sail bracket, and balance it with
bungee. If anyone is interested I'll let the group know how it
goes. The last few years we used a succession of autohelm 3000s,
attached to the wheel. Remarkable how people produce marine gear
that is not watertight. I wont do it again. Friends of mine swear
the simrads are submersible.

If anyone is ever Pacific bound feel free to drop a line and I'll
answer any questions. We left FL Feb 2002, spent a year in the
Caribbean, went through the canal, and stopped in New Cal. Nov last
year.

Cheers,
John Banfield
True Blue Voyager (#54)

 

 

5067

Aug 15, 2004

Ixchel has had the following Ham antenna for over 14 years. A SSB
antenna is the same. It has always received good signal strength
reports. Ixchel is a SeawindII Ketch.

The ideal antenna is high off the sea and not shielded by grounded
structures, such as masts of grounded rigging. On a SeawindII, the
triatic stay is the ideal member for an antenna.

Actually it is an antenna system, and the ground is equally important
with the aerial. The transceiver, water tank, automatic antenna tuner
and lead ballast keel should all be connected with 2 inch wide copper
foil. The lead can be accessed through the forward bilge compartment.
Drill down near the after end of this compartment, through the
fiberglass until uou penetrate at least a half inch of lead. Screw in
a threaded rod, or self tapping screw, seal with 5200 and attach the
foil to the screw head. The keel presents a large mass to the system
as well as a low inpedance path to seawater by way of capacitative
coupling through the fiberglass. Also connect the foil to a chainplate.

The use of an external ground plate is controversial, but if you use
one, it should also be connected with copper foil.

I mounted the antenna coupler adjacent to the port mizzen chainplate
and ran a lead of high tension wire (similar to spark plug wire)
through a gland at the deck and spliced to the remaining aerial
portion of the system. That system consists of a single piece of 1/8"
1x19 SS wire which runs from the mainmast head to the mizzenmast head
and then to the antenna coupler. It functions as the triatic stay,
so has little strain and can be constructed with nicopress fittings.

There is an insulator within 12 inches of the maimast head. Another
piece of wire must be spliced to the antenna before it reaches the
mizzen mast. This wire leads to an insulator and then to the triatic
turnbuckle. There is a metal strut attached to the port side of the
top of the mizzen mast. it is made of 7/8" stainless tubing, such as
might be used for deck stanchions, and attached to the mast with a
stanchion deck fitting. Wire an insulator to the end of the strut. I
use a cylindrical ceramic insulator, about 6 inches long with a hole
in each end. The upper end is held with monel wire to the strut, the
antenna passes through the hole in the lower end. The strut serves to
keep the antenna away from the mizzen mast.

The port forward mizzen shroud has two insulators, each abaout 3 feet
from the two ends. The antenna wire runs along the insulated portion
of the port forward mizzen shroud, and is attached to it with
nicopress fittings, although monel wire or even cable ties might
adequate. The bare end of the high tension wire is wrapped around the
end of the 1x19 wire, covered with conductive paste and carefully
wrapped with weatherproof insulating tape. The splice is slighly
above the lower insulator in the mizzen shroud. The high tension wire
is attched to the lowest portion of the mizzen shroud with cable ties
to keep it out of the way of persons exiting the cockpit. The
section of the mizzen shroud above the insulator is "hot" when
tranmitting, so avoid contact with the shroud at that time to prevent
rf burns.

The antenna consists of the high tension wire and the whole length of
1x19 all the way to the mainmast head.

I cannot imagine a more efficient antenna system on a Seawind II Ketch.

Dick Weaver, SWII 75K

 

 

5070

Aug 16, 2004

Dick,
Thanks heaps for the response. Lots of great advice. I have found
some earthing foil that i'll take with me.

Where you refer to the forward bilge compartment, are we talking just
behind the mast, or back level with the stove? I have a 'wine
locker' under the head floor that gives me some access forward. I
don't want to go prospecting for lead...

Thanks,
John

5072

Aug 16, 2004

My installation of a SSB is a bit different than Dick's. On Voyager we have
an insulator on one leg of the mainmast's backstay, just below the junction
of the two legs of the backstay. We feed the chainplate belowdeck from the
tuner. It's a short antenna but tunes just fine at all the usual ham and
marine frequencies. I had considered using the triactic but was worried
that the signal might have been too horizontally polarized - good to hear
there's no problem there!

For a ground I bonded the water tank to the engine and all, and connected
the SSB's and tuner's ground to that, using wide foil. The idea was that
the tank is large and would capacitively couple into the water and the lead
keel.

The entire installation works great and I get good signal reports from all
over. And when working at full power there's none of those strange effects
you find on bad installations - like the autopilot getting confused or
lamps glowing brightly. My Watchman radar detector does go "bing" if I
forget to turn it off, but that is so sensitive that it's not surprising.

We do use a manual tuner, which is probably a mistake since I'm the only
one who knows how to drive the darn thing. But too many decades of being a
ham led me to look for the "optimum" solution. It's sort of silly; like
driving a manual transmission instead of an automatic...

Jack, N3ALO, Voyager 057K

 

 

5726

Mar 10, 2005

Bert, Is there a way to hook up an SSB antenna in conjunction with the triatic under your configuration? AK

 

 

5727

Mar 10, 2005

Dear Andreszj: I have not given it a thought, as I gave up on the idea of SSB transmitting, just have a receiver. But it seems to me you could attach an antenna parallel to the line between the masts. That support system could avoid vulnerable load bearing insulators. The link to your SSB system.would be supported close to the sheave at the top of the mast.

Alternatively, you could use the Y backstay instead of the triatic for a more conventional antenna (that was my approach before I gave up on SSB transmission. I have not regretted that, silence being a boon to me when offshore, except for classical music or Cesarina of the Cape Verdes at anchor.

Be well, Bert dF

 

 

5732

Mar 10, 2005

Andrzej,

I'm an electronics engineer, so have thought about this a bit.

Using the triatic will make the radiated signal nearly horizontally
polarized, as the wire is arranged more fore and aft than up and down. Most
antennas on other boats will use the backstay, which is nearly vertically
polarized. Thus, your signal will be much less efficient; other boats will
have trouble copying you.

At the moment Voyager uses one lower leg of the backstay as the SSB
antenna. There's an insulator just below the plate that joins the two legs.
At the bottom there's no insulator; I removed the ground bonding wire and
feed the chain plate from below deck. The result is very satisfactory. But
someday I'll change this and insulate the very top of the backstay, and the
opposite lower leg. That will result in a much longer antenna.

At Bert's suggestion I changed Voyager's triatic to the adjustable
synthetic rope arrangement he uses. I find I get a better adjustment of the
rake of the mizzen this way, as well as the other benefits he has cited.

Jack 057K Voyager

 

 

5733

Mar 10, 2005

Jack,

Is this insulator above or below the split in the backstay? In other words, are you using only the bottom section of the backstay from the chain plate to the split? I plan on installing an Icom 706MKIIG on Integrity shortly and am trying to figure out the best way to rig the antenna. What are you using for an RF ground? My chain plates are not grounded except through the mast which is grounded for lightning protection via two dynaplates. I am debating whether to also connect the RF ground to the dynaplates (and so to the lighting ground). The advice I have read so far on this issue of connecting the RF ground to the lightning ground is mixed. Any thoughts or comments would be appreciated.

Regards,

Tony Torphy (AB2OZ)

Integrity, 126K

 

 

5735

Mar 10, 2005

Jack,

Thanks for your thoughts, especially since I know next to nothing about Ham/SSB comm, (yet I represent myself as a court recognized networking expert).

If I understand your advice, I should be able to install an insulator at the masthead, a 2nd insulator at one chainplate connector below the split and the antenna connector at the opposite chainplate. Is my understanding correct ?

As for lightning ground, I mounted a 1" wide, 1/8" thick, and 18' long copper strip along the lower portion of my keel. I've attached a 3/0 copper wire from the mast base to a thru bolt at the head of this strip. Also, I ran 4 gauge wire from each chainplate to the common bolt. I don't plan to attach my thruhulls to this. Should I attach my stanchions?
Also, do I need to attach the mizzen and back chainplates to the same bolt as the mast, or can I attach them to a bolt at the opposite end of the the grounding copper strip?

Thanks for your thoughts
AK

 

 

5737

Mar 11, 2005

Tony,

Currently the insulator is just below the backstay split, so the antenna is
just one lower leg (starboard) of the backstay. I think a better
arrangement, one I plan to install someday, is to insulate the other leg
just below the split, remove the current insulator, and put an insulator on
the upper backstay about 3 feet down from the top of the mast. That would
result in a long antenna.

For ground I bonded the aluminum water tank to the engine and the rest of
the boat's bonding system (all chain plates except the one that's part of
the antenna are grounded). The tank is rather huge, and acts like those
copper areas some boat builders place inside the fiberglass layup.

Jack

 

 

5738

Mar 11, 2005

Andrzej,

This is hard to visualize, so I've attached a very crude drawing of
Voyager's current and future antenna configurations.

As you can see the current setup uses just one leg of the split backstay.
The feed is to the chainplate from below decks, just out of the tuner. It
works great but the engineer in me wants to monkey with it and improve things.

The future configuration uses two insulators to yield one long antenna. The
jumper wire is a small bit of stainless wire, probably hose-clamped in
place, to eliminate contact resistance through the pins in the split plate.

As far as lightening grounds go, no one really knows a lot about this,
despite all of the hype. Your solutions sounds very effective. It will
probably dissipate the corona energy the builds and that can draw a strike,
and may even deal with a real strike. When a real hit occurs, though,
anything can happen. Since the VHF antenna is above the ground system it
may draw energy below and fry stuff.

Jack

 

 

 

5739

Mar 11, 2005

Tony: You have plenty of ideas now. I would add that when I was studying grounding, I was to combine the aluminum fuel tanks with the SS water tank for good measure, with copper sheet band links.

Do I hear aluminum water tank, Jack? Anyone who has one should try to replace it with stainless whenever possible (if leaks etc.), just in case the increasing evidence that aluminum intake is linked to Altzheimer, becomes incontrovertible fact.

Be well, bert dF Pianissimo 80K

 

 

 

5740

Mar 11, 2005

Bert,

Whoops! You're right, it's a stainless tank. I'm still groggy from getting
home from San Francisco at 0200 this AM.

Jack

 

 

 

5744

Mar 11, 2005

All,

Thank you all for the responses.

Bert,

I also plan on connecting the SS water tank, fuel tank and engine as part of my RF ground. I used the 3" copper foil from Defender to connect them together. As far as lightning and the VHF antenna is concerned I plan on installing a Polyphaser surge arrestor (Polyphaser make excellent arrestors which also have a DC block feature). The DC block is useful because the coax ground connection at the VHF antenna can inadvertently create a ground loop. They cost about $60.00 or so but may well save an expensive VHF radio.

Jack,

Many thanks for the info and the sketch. I will probably go with a Ham Stick for this season and install insulators next winter (too many projects still to be done this Spring!). I think I will also install a 2 meter/70 cm dual band antenna on the mizzen mast.

Andrzej,

From what you have described I think you have an excellent lightning protection system. Integrity has the main mast bonded with # 8 copper conductor to two "Guest" bronze plates. Your cable is much heavier and that is better. I would recommend that the cable be kept as straight as possible. In general a good lightning grounding system is really about minimizing the damage from a strike and protecting the people on board. One school of thought is to have the main mast grounded directly to the grounding plate and the chain-plates and other large metal objects bonded using horizontal runs with smaller diameter cable leading to the grounding plate. The thinking is that you need to create an equal potential zone but avoid having multiple paths for the strike to travel to ground. The horizontal conductors for the chain-plates would look like a high impedance path to a lightning strike. On the other hand, there are other folks who believe that the chain-plates should be left ungrounded. In any event, I think the mast should be connected to the sea via a low impedance ground and the insurance policy paid should be up to date J

Regards,

Tony

Integrity, 126K

 

 

5745

Mar 11, 2005

Tony: to this great summary, I would like to add the cheap additional protection of an ion dissipator on top of each mast:a simple flyswish of metal that sticks up from each mast. Even the military now has some hightech ones, but on the same principle as the cheap version. Some people use a bottlewasher type that is quite more expensive, but again same principle. Be well, Bert dF, Pianissimo 80K.

 

 

 

6527

Jan 24, 2006

I am considering replacing the Loran antenna at the top of my mizzen mast with an SSB antenna for Ham and Marine HF. Any thoughts on the effectiveness of an SSB whip versus an insulated backstay? Also, any thoughts on whether or not to give up the Loran (mine is not working so I thought it would be a good time to remove it).
Regards,
Tony Torphy (AB2OZ)
Integrity, 126K

 

 

6528

Jan 24, 2006

My original whip was 16' high. I had a tuner on it and it worked ok but not great. I think they stopped making it and replaced it with a 23' whip. Before I go down that road I started considering using a shroud and the triatic isolating them with 4 insulators. Being cheap and simplistic, it occured to me that I could run a wire from the main mast back to the mizzen shroud. I measured that at 38'. Figuring 3' at the top and 5' at the bottom made of non conducting line and tapping in with GTO-15 to the tuner I would have a 30' almost vertical. I'm planning to tap into the keel just forward of the water tank and run either braid or copper strip to the tuner. Cheap and simple. I'll let you know how it works unless someone advises me that the plan is ill conceived.

Howard

 

 

6529

Jan 24, 2006

Size matters.

The ham/maritime SSB freqs are a few MHz to 30 Mhz. The ideal antenna
is 1/2 or 1/4 wavelength, which at 30 MHz (1/4 wavelength) is
15meters, more than we can usually do on a Seawind. Thus we use
tuners to try to compensate for our inadequate antennas. It's all a tradeoff.

On Voyager we insulated one leg of the main backstay. Only one
insulator is needed; the feed is at the chainplate. The result has
been excellent coverage. We routinely get all of the usual maritime
freqs, and do phone patches on 20 meters on the ham bands all the
time at sea. That does require a ham license, though. But it's a
great way to stay in touch with the family even when 1000 nm
offshore. Once the ham licenses were difficult; now the Morse code
requirement is only 5 words a minute, which is quite easy.

Most ham and maritime antennas are vertically polarized, which means
an antenna that's more or less vertical will be the most efficient.
So the backstay is pretty good. The triatic is less so. A decent
ground is just as important, but we Seawind owners are lucky. The
water tank is a huge metal array below the water line. On Voyager
we use that as the ground, bonded carefully to the engine and seacocks.

Jack, 057K Voyager and ham N3ALO

 

 

 

6531

Jan 25, 2006

Howard:

The antenna you describe is essentially the one I have used for 15
years. I use it for Ham frequencies but SSB would use the same antenna.

I think you will need a small horizontal athwarships strut from the
top of the mizzen mast to keep the antenna away from the mast when it
transfers from the triatic stay to the mizzen shroud. Mine is about
10 inches long, made from aluminum tubing. The antenna is hung from
an insulator at the end of the strut.

I have always gotten excellent signal reports.

Dick Weaver, SWII 75K

 

 

6535

Jan 25, 2006

Bert,

Thanks for the advice on shedding the Loran, I think I will do likewise.

Jack,

Alas, once again it seems that size does matter! I also considered insulating the backstay. However, I was planning on installing two insulators one at the top and one where the backstay splits. It would be grat if I could get away with one. Is your backstay insulated at the top near the main mast or below the backstay split? My thoughts were to install the tuner in the starboard lazarette and feed the stay via the chainplate. My concerns were the cost of insulators and adding weak points into the rigging. So far I have limited my maritime HF work to 20 and 40 meters using ham sticks. I recently bought a 20 meter Zepp antenna (end fed dipole End Fedz made by Par Electronics). It is fed at one end via 50 ohm coax and is about 33 feet long. The Zepp can be hauled up using a spare halyard and connected directly to the transceiver (without the need for a tuner). I plan on having some Zepp and bazooka antennas on board to play around with (also useful if you lose your main antenna). I have been using the Zepp from home for the last few weeks and it seems to work very well. You can read some reviews on the Par Electronics End Fedz at http://www.eham.net/reviews/detail/3632.

Howard,

I have read that braid corrodes very quickly in a marine environment. I used 0.003" copper foil from Defender and ran it from the starboard lazzarette to the engine, bonded to the water tank and connected to two dnyaplates (one port and one starboard) in the bilge area directly under the mast (the dynaplates were installed by a previous owner for the Loran and for lightning protection. I found the 0.003" copper foil to be too thin and believe it will corrode quickly. I would recommend thicker foil. I have also considered buying some copper flashing at Home Depot and glassing it into the inside of the lazarette to add to the RF ground. Once we get the boats back into the water we should arrange a sked to check out our installations.

73 (Regards),

Tony Torphy AB2OZ

Integrity, 126K

 

 

6536

Jan 26, 2006

Tony,

I used one insulator, place at the top end of the starboard leg of the split backstay (right below
the triangular plate that links the three backstay pieces). I drive the chainplate from under the deck. The rule is --- don't touch the backstay while transmitting!

But eventually I want to change this, and put an insulator on the upper backstay maybe three feet down, and another on the port leg near the triangular plate. That'll result in a much longer antenna. I'll probably go to all 1/4" wire for
strength purposes. The insulators are quite strong.

At the moment Voyager has a MFJ manual tuner under the radio. It gets really low SWR readings, but is a pain to use, and I'm the only person who can tune up. So eventually I want to put in an auto-tuner.

73,
Jack N3ALO, Voyager 057K

 

 

6538

Jan 26, 2006

Jack,

If I understand it correctly, your antenna includes only the starboard side of the split back stay. I think that might be too short for my rig and tuner. I have an Icom 706 MkIIG and an AH4 tuner. The AH4 tuner requires a minimum antenna length of 23 feet. Eventually, I plan on installing an Icom M802 or similar. An insulator at the top of the back stay (3 or so from the mast) would add considerably to your antenna. I have also considered using one of the mizzen stays and the triatic (similar to the system on Ixchel). I think that may be the best way to go if using an insulated stay. I will probably end up replacing the Loran antenna with either an SSB or VHF/UHF (144 mhz 440 mhz) antenna.

73,

Tony Torphy (AB2OZ)

Integrity, 126K

 

 

6539

Jan 26, 2006

Jack,

As I'm in the midst of rerigging this is very interesting to me.
Though pardon my ignorance, but, could I use one of those insulators
from Hyan and place it at the top of the back stay?

Perhaps I'm misunderstanding Tony's refrence to the "3 feet from the
mast" comment. Is it necessary to install a length of wire between the
mast and the insulator, or can I attach the insulator directly to the
fitting at the mast?

Thanks,
AK

 

 

6540

Jan 27, 2006

Andrzej,

I don't know the Hyan brand but imagine it's OK.

You don't want the insulator all the way at the top of the backstay;
it needs a short length of wire between it and the mast. Otherwise
the mast, which is grounded, gets coupled to the antenna. In effect,
at RF frequencies, the top of the antenna is almost grounded. Sounds
odd, I know, but RF is sort of magical.

Jack

 

 

6541

Jan 27, 2006

Understood.

Since the SW1 has slightly different dimensions than the SW2, is there an ideal length?

I read a prior post that quoted 15 meters. Does the length have to be linear?

As always, thanks for the advice.

AK

 

 

6543

Jan 27, 2006

Andrzej,

The length of the antenna depends on the frequency to be used. The lower the frequency, the longer the antenna needed. To compensate for the wire not being resonant (the right length) at a particular frequency, the tuner inserts inductance and capacitance into the circuit. An insulated backstay coupled to an antenna tuner allows the wire to behave as if it is a longer (or shorter) wire. The length does not have to linear; however, bending the antenna will make it radiate its signal in different directions (not necessarily a bad thing). Antenna theory can be complex and there are several computer programs designed to predict antenna performance. The RF ground system is another critical component of an HF antenna system. The following links give some good info on marine SSB radios.

http://www.icomamerica.com/ Select "downloads" and then "misc. files" from the main menu. The "Marine SSB Single Sideband Simplified PDF" is an excellent reference.

http://www.sailmail.com/grounds.htm

http://www.geocities.com/bill_dietrich/Radio.html

http://www.sgcworld.com/Publications/Books/hfguidebook.pdf

Regards,

Tony Torphy (AB2OZ)

Integrity, 126K

 

6547

Jan 30, 2006

Andrzej,

Tony sent some excellent references, so I'll just comment that an "ideal" length is 1/4 of the wavelength you're transmitting on. But we're on so many frequencies it's impossible to achieve this. The tuner essentially fools the antenna into thinking it's the right length, which is why you have to retune as you change frequencies.

Jack


7032

Oct 4, 2006

Hi All- I am replacing all my standing rigging and want to set it up for a future ssb radio. I seem to remember some words from Jack and Dick on the pro's and con's of using insulators around the delta plate on the split backstay versus using the triatic stay. My computer crashed and I lost my notes on this..Does anyone remember or can anyone advise me which way to go?
Thanks...
Bill S. , k113