Tagged: SSB Install
28th December 2016 at 3:46 pm #19942
I am planning to install an ICom m-802, antenna tuner and plan to use main mast backstab as the antenna.
It would be very helpful to learn the placement of components others have chosen, as well as what has been done for a successful counterpoise. Lastly, any thoughts about RF exposure depending upon placement of the antenna tuner.
David28th December 2016 at 5:35 pm #20200
There seems to be a lot of misinformation on the counterpoise subject. Here is an example of a patented commercially available system for use in any size boat: http://www.kiss-ssb.com/index.html
It appears to be a collection of different length wires in a plastic sheath. The reason for this is that a single length of wire will be resonant at a single frequency so in order to cover the large frequency range used in marine SSB they have used a collection of different length wires to cover the bandwidth required.
Many people have over the years just installed a copper strap to the bronze through hull fittings thinking that the HF signal needs a ground to the water but really all that is required is a length of wire to provide an opposing signal to the main transmitting antenna.
You could probably simulate the Kiss-SSB system by putting a number of different length wires onto the ground connection of the tuner.
Obviously the back stay needs to be insulated with ceramic insulators and I would place the antenna tuner as close as possible to where the actual antenna lead comes into the boat to minimise radiation inside the vessel.
Antony29th December 2016 at 1:49 am #20224
Thank you for your reply!
KISS has been promoted as a simple and somewhat effective counter poise. The idea that one can produce similar results with measured lengths of wire has also has generated interest. However, some testing has caused some questions about effectiveness of each approach. (Will look for this research and post.)
Gordon West conducted extensive testing of counterpoise that I consider more substantive:
http://www.carsonhowe.com/files/GordonWest_on_ground.pdf this is a thoughtful read. Or to learn more, just google Gordon West and see impressive list of material.
Again, thank you for the thoughtful reply.
What works most effectively on NC33 remains my challenge. Hoping to also hear from Those who have installed before.
Thank you, again.
David29th December 2016 at 10:21 am #20233
I have read some of Gordon Wests posts on the subject although not the particular article you mentioned.
Unfortunately the patent number does not appear on the Kiss-SSB web site or I would look it up.
My experience has been installing and commissioning HF radios and Antenna Tuners on aircraft in Australia during the 80’s. If you think about it aircraft have a similar problem to GRP yachts in that the air-frame becomes the counterpoise by default since its not very convenient to ground it at 20,000 feet 😉
I always believe in keeping things as simple as possible and learning from other peoples experiences so I too would be interested to hear from members who have successfully installed an HF SSB transmitter on a Nauticat.
Regards Antony30th December 2016 at 3:13 pm #20275Vic CrowhurstParticipant
On our two Oyster 15m ketches used in the “Tall Ships “races, we have Icom802’s, auto tuner nearby and coax out of the cabin to the port main mast midstay aerial (running backstays), starting 2m above the deck to reduce the risk of rf burns and shock. The ground is a thru hull outer bronze plate 25cm x 15 cm x1.5cm connected to the tuner ground with copper foil 7.5mm wide. The plate is 20cm above the keel/hull junction and in line vertically with the aerial and this reduces the chance of un-wetting when on Port tack. The plate is cleaned and abraided religiously at each annual refit.
I had considered putting ssb on my Nauticat 37 but doing the sums, It would be cheaper to hire a sat-phone for the brief times I would use really long range coms.
Having sailed from Kristiansand to Southend in a straight line, nonstop, I was amazed at how often I could hear and talk to Ships and Rigs in the North sea on VHF ch16.
I would commend to you the principle of allowing radio wattage to flow in the shortest straightest route by the widest possible conductors. I anticipate you could fit the Icom black box and tuner in the space above the microwave oven with the head and mic in the passage way above the 3 storage drawers, to be used from the helm position maybe.
I’d be interested in your results.
Vic Crowhurst2nd January 2017 at 3:47 am #20611
Thank you all, for your responses.
Below is link directly to Gordon West White Paper on counterpoise.
Very interesting read.
Still looking for previously read analysis of KISS by a skeptical, and obviously technically savvy US amateur radio operator.
Antony: I agree with the simplicity issue. The KISS offers this and has advocates. There are also those who claim they had terrible experience until they added a seawater based connection.
Vic: I do not know the layout of the Oyster 15. I assume your installation of the radio and control head is on the Oyster 15? Based upon your description, our NC 33 configuration options appear to be different.
I have considered mounting the radio transceiver below the salon seating in main salon, and control head at the pilot house Helm. The issue with this is that sitting and using controls might be mildly awkward when sitting and communicating in harbor, getting weather fax, etc. The advantage is the controls would be accessible while underway.
Re: counterpoise: I have several options for using copper foil to connect to underwater thru- hulls as well as a bronze plate near keel. I admit concerns regarding electrolysis.
However, my biggest question has to do with the antenna tuner (AT-140), antenna lead and the related potential for RF exposure to humans within cabin. If AT is installed in the aft hanging locker, and antenna lead wire is run up to main mast backstay located on cabin top, there appears potential for RF in area of aft cabin and in seating within the pilot house. So, as a less elegant option, I am considering installing AT on cabin ceiling directly below where antenna lead would exit to connect to main mast backstay. This would be less aesthetic, but shorten antenna lead and put RF above people sitting in Pilot House. Does my description make sense? Open to suggestions and again, appreciate comments.
Again, thank you for assisting me with thinking about this. I still hope to get photos and hear from people who have installed SSB in NC33.2nd January 2017 at 6:54 pm #20629
RE: Counterpoise, KISS, etc.
For those willing to slog through a long discussion, consider:
Cruisers Forum. It starts at:
and goes on for about 25 pages.
There is a lengthy, sometimes heated, sometimes overly technical discussion, that does provide very interesting perspectives, experiences, RF tests and solutions regarding KISS and other counterpoise methods such as Direct to Earth, Capacitive, Bulk and Resonant (which is what KISS employs).
I am continuing my research. Thanks all. (hope it is ok to post links to other forums while in search to solutions.???) best,
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