Rope Antenna for SSB

[Brisa]

I am about to buy an ICOM M710 radio and a rope antenna seems the least expensive and simplest antenna solution for me. Do they work well? Or too cheap to be real? I have 2 dynaplates installed and my through-hulls linked with copper. I would like to know what others have experienced with rope antennas.

Brisa

[svHyLyte]

Click on the Search Button (between "New Posts" and "Quick Links") above and insert "Rope Antenna" in the Search For window and hit "Enter". There are already upward of 100 discussions of the subject.

[Hannah on 'Rita T']

A quick answer is that ours works fine on an Icom 802 with a dynaplate and linked thru-hulls.

[velero]

Mine works great with copper foil between the tuner and one thruhull.

[sailordiver]

Does anyone have experience using a rope antenna on a Whitby 42 Ketch? Where did you place the antenna?

[Tony B]

This has got to be the greatest con job ever.
It's a wire antenna stuck inside of rope. For what reason other than a marketing gimmick is beyond me. Maybe it's a magic rope.
The rest is no different than any other antenna.

[mlibkind]

There is an easy to install alternative to the rope antenna. It's called a GAM. It is permanent on the back stay, but does not require cutting the stay and installing insulators. Unlike the rope antenna, the GAM is always installed and connected. In an emergency you don't want to be having to hoist the antenna. You should also look at the KISS alternative to traditional grounding.

Also, take a look at Sea-Tech if you are interested in an ICOM 802 package. They probably have the best price going.

[Jimbo485]

Anyone want to buy my rope antenna?

$100.

We are in Brisbane and I will throw in a non-working ICOM IC-725 and tuner and manual as well. No shipping but I will help you uninstall it all.

[Goudurix]

Answering Brisa's original question:

Transceiver and RF-ground systems looks really OK!

I have nothing against commercial products like the "Rope-Tenna" or the GAM but you can make this yourself far more cheaply! Do a search for "alternate backstay antenna" this is just it.

You can use either:
- SS wire (slightly less conducting off course then copper but not significant in this applciation and very strong)
- insulated copper clad steel wire or other type of wire antenna that can be found in your typical HAM store

You will need also:
- an isolator at the top from where you hoist up this wire antenna from a spare hayard (just the nylon wire might be enough but it is certainly best practice to use a lightweight RF isolator -HAM store again)
- some easy-built plastic or nylon standoffs (I used some of the HAM-style isolators for this) if you need to lead the lower part of your antenna wire along a pulpit rail or other SS hardware
- an isolated watertight through hull to lead your antenna wire through the deck to the automatic antenna tuner
- and off course (you did not mention it: an ATU (automatic antenna tuner) like Icom AH4, SGC-230 or similar) IF you want to use this type of "sloping end-fed wire antenna" on multiple frequncies. If you chose a suitable Icom atu you will be able to steer it from the Icom marine SSB for tuning

One remark:
The big advantage of own-built sloping wire antenna over fixed length Gam's RopeTenna's and isolated backstay is that you can chose an optimal wire length according to your target frequencies!

The typical 43 feet of isolated backstay + the typical GTO wire running down to the ATU will favour the lower frequencies until 14 Mhz hence the main marine SSB frequencies for llong distance communication.
If on the other hand you want to favour HAM DX frequencies like 40 m band up till 21 Mhz/15m band a total wire length (top of wire until the antenna connection lug on the ATU) of about 9.2 metres should work OK. For frequencies lower than 6 Mhz you will lose effeiciency but it will still work! For the latter setup (9.2 m) my SGC230 atu still tunes 2.2Mhz easily.

Jan
ON3ZTT

[S/V Alchemy]

^ ^ ^

I think this is good advice. The deeper you get into SSB, the more likely you're going to learn which frequencies you frequent (so to speak) and will want to optimize your antenna to those. Making your own antenna is a fraction of the cost, too.

It's like the argument about using a splitter to run an AIS and VHF. That will work, but there's a few arguments in favour of using an AIS only whip antenna that is cut for the rather particular AIS frequencies. That way, you get the most in terms of range.

[Tony B]

I don't use marine band SSB only HAM band SSB. I don't even know the frequencies of marine SSB but I would bet they are close to HAM band frequencies. If they are close, you can probably use Ham Sticks.
All I use are HAM Sticks. These are loaded whip antennas that screw into a base that that can be handrail mounted or on a flat surface. The sticks are between 4 and 5 foot long with an adjustable 'stinger' on top. Usually adjust one time and that's it forever. Each stick is for a different band of frequencies, can be screwed in place in seconds if you change bands and are under $20 each. There is no real construction or wiring involved other than running your coax, screwing the base to a handrail and screwing the whip antenna in place.
NO ANTENNA TUNER NECESSARY.
As for a ground plane, they are not necessary over water. The ocean becomes your ground plane. A ground plane is nothing more than a reflector. It reflects the radio waves off the surface and onto your antenna.
Not wanting to get into antenna design here but to simplify this - most wire or vertical antennas are what are called quarter wave antennas. With a ground plane reflecting back at it, you have created a mirror image so to speak. This reflected image added to the actual antenna now creates what is called a half wave antenna.
The ground plane does not have to be electrically connected to the antenna.
I talk can around the world with this set-up. Try this first, if not happy, hang a wire into the water. You probably wont be able to tell the difference.
Try this with any antenna system over the water. Start out without the gimmick ground plane and make a contact. Then hook up the store bought ground plane and see if you can tell the difference.

[Goudurix]

Tony,

sorry but on a sailing boat having the advantage of the mast I would certainly go for a long wire antenna over hamstick.

One might argue that the efficiency you loose in the coils of your hamsticks we might loose in the ATU.

If one wants the best efficiency and no tuner than vertical wire dipoles specific per frequency are by far the best solution.

Since int this case the coax cable is not running perpendicular fom the dipole and since I only use them in temporary setup (quietly on anchor with a good cold beer at hand) I built them "along the book" with 1:1 current balun at the dipole center. (I know Bill Trayfors doesn't think this is worth the trouble).

Jan
ON3ZTT

[NahanniV]

Originally Posted by sailordiver

Does anyone have experience using a rope antenna on a Whitby 42 Ketch? Where did you place the antenna?

I asked a similar question, for a boat with a similar rig, here:

http://www.cruisersforum.com/forums/...tch-94909.html

I have not decided what to do yet.

Cheers,
JM.

[Tony B]

We are planning on coastal cruising this Sun or Monday.
I haven't been on HAM radio in over 7 years. I bought some HAM sticks on Sat and mounted it on the end of my Dinghy Davits so it would be over the water about 9 feet or so.
It was about 3PM CST and decided to see if my equipment still worked. First call I contacted a man in Ontario, Can. on 28.350MHz (10 meter band). OK everything seems good so far. Next call I went to 14.300Mhz - the mariners net. It was a clear call to a guy in Seattle area. I had other things to do so I decided not to even fool with the 40 meter whip because I am sure it will be good.
I used simple HAM stick clamped to the dinghy davit arm with no ground plane except the water itself with no direct connection to it. I do not own or have an antenna tuner.
There may be better systems than this, but how much better do I need?

Considerations with using back stays and other high rigging:
1). Lots of extra work with maybe as good a performance as a whip.
2). Are you guys aware that the terminal connections will corrode in a salt water environment? They will and then how will you clean them? Re-rigging all over again?
3) Here is a biggie - HAM frequencies are not that far from marine frequencies. The whips have adjustable stingers. They can work - or just buy SSB whips if it will make you feel better.

Goudurix: "If one wants the best efficiency and no tuner than vertical wire dipoles specific per frequency are by far the best solution."
I can change whips in under 20 seconds. Can you do that with vertical dipoles?

One more note to marine band radio folks. The reason some of us are talking about different frequencies is because the higher frequencies are only good during the daylight hours. The lower frequencies are better during the night hours.
Has to do with the ionosphere and radio wave propagation.

[Goudurix]

Tony,

if you are happy with your system, that is what matters!
Anyhow on your type of boat it's either a large 23 ft whip or larger, or something like your hamsticks.

I do not really need marine SSB for the short coastal cruising cruises and cross channel( Belgium-UK or France-UK) cruises I do, so it is HAM radio for fun and the good low take-off angles on gets over seawater.
But then again I don't get excited over a 2.000 mile DX contact to Greece or Casablanca...I get excited about DX to Japan, Alaska, Buenos Aires, Djakarta or Perth. I expect this will work better with my 17m vertical dipole over seawater.
Indeed it takes about 10 minutes overall to hoist a vertical dipole. 2 more minutes to get my fresh (belgian!!!) beer.

And if I'm honest...on 17m the results are also very good on my end-fed sloping wire and ATU.

Good winds (or wintersleep)
Good DX

Jan
ON3ZTT