Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 28-10-2010, 12:49   #16
Registered User
 
cburger's Avatar

Join Date: May 2006
Location: Nyack, NY
Boat: Westsail 32
Posts: 1,547
Images: 1
Thanks Bill, the old Sea 222 ssb on my boat needs a new ground and am planning on trying the KISS. As an update my client called me the other day from Virginia and has indicated that he has finally getting up to speed with his new radio install. Was able to make contact with a base in Alabama.
__________________

__________________
cburger is offline   Reply With Quote
Old 28-10-2010, 12:59   #17
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
A word about Instructions and "manuals" and "texts" on SSB, since it was mentioned above.

Do not believe for one instant that the manufacturers of SSB equipment -- even very large ones like Icom -- always get it right when it comes to antennas. They don't. In fact, more often than not their advice is misleading or just plain wrong. Antenna systems, particularly those on sailboats, are very complex indeed and all too often what you'll see are the same old tired impreachments:

- you need 100 square feet of copper for an effective ground;
- wire won't work since RF travels on the outside of metals; you must use wide copper straps;
- tie your tuner into the boat's ground system;
- tie it into the keel;
- tie it into water tanks;
- connect it to the engine;
- don't connect it to the engine;
- connect the radio ground lug to the tuner ground lug;
- you must have one or two external ground plates for an effective ground;
- you can capacitatively tie your RF ground to seawater without a direct connection
- etc., etc., etc.

ad nauseum

Much of this advice is just plain wrong and, as in the case of grounding to the engine or "the boat's DC ground system" positively conflicting advice.

An example of this is in Icom's 12-page instruction manual for their popular AT-130 tuner. Under the section entitled, "Ground and Counterpoise" on page 2, they mostly got it right. But the ship's ground terminal is given as an "Ideal Ground Point", while the engine block is given as an "Undesirable Ground Point", with the note that this may cause "noise or electrolysis". Well, the ship's ground point and the engine block may well be one and the same, or at least effectively the same if there's a buss bar nearby which serves as the ship's ground.

Good for Icom, though, in the next paragraph entitled, "Counterpoise", they got that mostly right! And, FWIW, this is precisely the mechanism which the KISS-SSB radial ground system is based upon.

Bill
__________________

__________________
btrayfors is offline   Reply With Quote
Old 29-10-2010, 10:01   #18
Registered User

Join Date: Sep 2008
Location: Camden, ME
Boat: A Thistle and a Hallberg-Rassy 36
Posts: 661
Lets keep in mind that a 50 ohm dummy load will give 1:1 SWR and allow full power output from a transmitter while radiating no power at all. So your transceiver or outboard power and SWR meters do not tell you how well you are actually radiating power, just that your transmitter is happy that all the power it is generating is going into a load somewhere - but not necessarily into free space where you want it. If you are getting a match with your antenna tuner but have a poor antenna/counterpoise system, much of that power is being dissipated in the antenna tuner itself, functioning like an expensive dummy load.

Using the Reverse Beacon Network, I can see my ham transceiver delivering readable signals 1000 miles away with the power set to zero. In fact it is still putting out 1 to 2 watts or so, but my power meter doesn't read that low. As hams who love QRP (low power operating) will tell you, you don't have to radiate much power to make very long distance contacts with somebody. It is when conditions for a point to point contact are poor that radiating most of your 150 watts, instead of just a few, will make a difference.

Point being that SWR and power output indication on the transceiver, and the ability to make some long distance contacts, are not reliable indicators of effective radiated power.

The KISS SSB is not equivalent to a resonant elevated radial system for a vertical. It is typically sitting down in the hold inches away from seawater and below the water line, where it cannot deliver radiated power with the same efficiency as a vertical dipole, or a vertical with elevated radials. Coil it up to save space like some do, and you are probably making matters worse.

I suspect that the KISS SSB is working with about the same efficiency as a copper ribbon run to a bronze through hull. Its built in coils may well make it easier for an antenna tuner to deliver a match, but in that capacity it is simply acting as a crutch for a tuner which might or might not have the right inductors to make the match on its own.

Apparently the device works well enough to make many people happy, particularly given the ease with which it is "installed". Thats great. Its only $140, a pittance compared to so many other parts on our vessels. What we really do not know is how it objectively compares to a wire run to the bronze through hull or other traditionally recommended ground systems. It would be a huge project to study this in a rigorous and reproducible fashion, so I doubt we will ever really know. In the spirit of amateur radio, I would say go ahead and give it a try and see if it meets your needs. I am certain it will not match the radiating efficiency of the vertical dipoles that Bill T. touts, or a backstay antenna system with truly resonant elevated radials, and I doubt it will prove to work better than many easy and much cheaper alternatives.

I'll just conclude by saying that if you buy and install this thing thinking you have made your radio ground plane/counterpoise system as good as it can be, you are probably wrong. If you are lucky, it will be good enough for your purposes.

Chip
__________________
SoonerSailor is offline   Reply With Quote
Old 29-10-2010, 10:30   #19
Registered User

Join Date: Apr 2007
Posts: 718
Very well said. Modern automatic tuner's will match just about anything you connect to them and even nothing at all at low power. As Iv'e said before on this and other forums, I have bench tested Icom tuner's in my shop and they will tune all bands with nothing connected to the antenna and ground connection. Now, you wouldn't want to use full power under this condition but the tuner only gets 10 watts in tune mode and the tuner easily handles that with no antenna. I make long distance (hundreds to thousands of miles) contacts in my vehicle all the time with one of these tuner's and just an 8' whip. A very very inefficient antenna system but under the right propagation conditions, it works.

Eric
__________________
fairbank56 is offline   Reply With Quote
Old 29-10-2010, 11:38   #20
cruiser

Join Date: May 2010
Location: SF Bay Area; Former Annapolis and MA Liveaboard.
Boat: Looking and saving for my next...mid-atlantic coast
Posts: 6,197
Concur totally with Chip.

Some thoughts and questions though for the fellow HAMsters.

- grounding does FX reception particularly on higher bands due to harmonics?

- AC vs DC grounding needs - AC more important?

- Does higher levels of low level ground radiation, particularly because you are at sea, FX transmission (and maybe reception) and that's why KISS is able to compensate in some cases?
__________________
SaltyMonkey is offline   Reply With Quote
Old 29-10-2010, 11:59   #21
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
I gotta agree almost 100% with Chip, and Eric. In fact, much of what they say is echoing my own thoughts, experience, and statements.

The "almost" is because we really don't have direct empirical evidence comparing the KISS-SSB with other common RF ground systems or with "truly resonant elevated radials". In fact, given the vagaries of radial installation on sailboats and the problems attendant to adjusting physical length to desired electrical length (velocity factor compensation), I doubt if there are any truly resonant elevated radial systems out there in the cruising fleet.

Also, we don't have a lot of data to go on with respect to the performance of radials down low in the bilge. A boat sitting in the water creates a crater in which the bilge-run radials are sitting on the crater's surface, so their efficiency in generating relatively high-angle radiation might be better than their efficiency in generating low-angle radiation...the kind desired for long-distance contacts. Can't prove it, but it makes sense.

It is also true that additional radials....up to a point...increase radiation efficiency. One would therefore think that the addition of more radials to complement the KISS-SSB system would improve signal strength somewhat. Or, maybe, a second KISS-SSB run away from the first one. That would be fun to try sometime but, as Chip suggests, it's not easy to set up a good experiment with repeatable results.

With my experienced ham/boating friends I've thought about doing such experiments for some years now. We have the boats, the equipment, and the will, but the deeper you think about what is involved and what kind of research protocol(s) would be required to obtain reliable results, the more you think it should be left up to an independent laboratory with a healthy complement of scientists and lots of (government) money.

For the time being, we do what we can. Each boat is different and the KISS-SSB ground system isn't for everyone. However, for many -- including some boat's I've worked on -- it's a very good solution.

Bill
__________________
btrayfors is offline   Reply With Quote
Old 29-10-2010, 15:29   #22
Registered User
 
cburger's Avatar

Join Date: May 2006
Location: Nyack, NY
Boat: Westsail 32
Posts: 1,547
Images: 1
I am curious about some of the posts here. I am under the impression that sapce vehicles communicate via SSB systems including Apollo from the moon and considering that ssb has been going to sea on sailboats for years one would think that there is data somewhere that indicates what the best overall system design would be?
__________________
cburger is offline   Reply With Quote
Old 29-10-2010, 16:06   #23
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Virtually all space communications are at VHF frequencies and above (UHF, SHF), not on the HF frequencies we're talking about here.

Many amateur stations re-broadcast these on amateur HF and VHF frequencies.

Re: the "best overall system design", it's a nonsense question.

Man has been sailing for at least 5,200 years. You'd think by now someone would come up with the best sail plan!

Bill
__________________
btrayfors is offline   Reply With Quote
Old 29-10-2010, 16:45   #24
Registered User
 
cburger's Avatar

Join Date: May 2006
Location: Nyack, NY
Boat: Westsail 32
Posts: 1,547
Images: 1
Re: the "best overall system design", it's a nonsense question.

Bill, as CF's duly elected expert on SSB I am sorry you feel my question is "Nonsense", I promise I will try and do better in the future. The question that I was trying to have answered is with all the experience in sailboat SSB is there one setup that is typically utilized more than others due to its on "Average" better overall performance under a broad range of conditions as Chip seems to suggest.

The space part of the question is based on my thinking that regardless of bands utilized basic radio theory is basic radio theory and the guys at NASA might of had some interesting things to say regarding grounds, antennas, radials, etc. ?

Man has been sailing for at least 5,200 years. You'd think by now someone would come up with the best sail plan!

They did its called a "Cutter"

Bill[/QUOTE]
__________________
cburger is offline   Reply With Quote
Old 29-10-2010, 18:12   #25
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Sorry about the "nonsense" remark. Jumped too fast :-)

Still, if you stop and think about it, the question is unanswerable both in its original form and the restated form. There are just too many variables. Boats differ markedly, one from another. Even boats of the same design may differ in several important respects.

The most commonly seen SSB installation on sailboats is one which uses an insulated backstay and an RF ground which makes -- or attempts to make -- some sort of connection to seawater. Why? Well, most likely because virtually every text and instruction sheet on marine SSB advocates such a setup. This is certainly the "safe" way to go. A nice DC connection to the water from the tuner, and an insulated backstay with the lower insulator way above your head. I just worked on a Hinkley with the lower insulator 15' above the deck, presumably to protect any giants among the crew from the (very remote) possibility of an RF "burn".

Just because it's the most common installation doesn't mean it's the optimum solution. Not by a long shot.

What can we learn from NASA and space communications that's applicable to boats? Well, for one thing, a RF ground connected to the earth ground isn't either necessary or possible! But we don't have to go into space to learn that. Consider mobile operations on land. VHF and UHF antennas work extremely well in vehicles, using the metal bodies as a counterpoise. HF can work pretty well, too, even though the vehicle is well insulated from the surrounding terrain by it's four (or eighteen) rubber tires :-)

Land-based vertical antennas can work well, too. Here's where the experience of radials comes into play, and where many studies have de-bunked the old radial theory that you need lots of them...may even hundreds...to get out a whopping signal. Not so. It turns out that just a few radials elevated a bit above ground -- instead of laying on the ground or being buried beneath the ground -- do a very credible job. Broadcast stations find that elevated radials located over water or swampy areas do the best job, because they get a good "bounce" from the water, the surface of water being a much better conductor/reflector than soil.

In marine SSB installations, particularly on a sailboat, there are so many variables that it's hard to say with certainty what is best "on average". Moreover, unless you know something about the specific boat and the communications desires of its owner it's even harder. For example, if the owner wants to mostly contact boats and shore stations relatively nearby, including after sunset, you'd want to have a setup which would favor the lower bands. If his/her desire is to circle the globe, and to communicate mostly over very long distances, then you'd want to install a setup which would favor the higher, longer-distance bands. These considerations would influence not only your choice of antenna and it's length, but the RF ground system as well.

In the world of marine SSB, I've learned that no one size fits all, however much we might be comfortable with a cookie-cutter approach.

As to my being "CF's duly elected expert on SSB" I can only say that over the past 45 years of hamming and playing around with HF installations on boats I've made lots of mistakes and have learned a thing or three....by training, experience and, most of all, dumb luck. But there are lots of guys around who deserve the "expert on SSB" label more than I.

Happy weekend!

Bill

BTW, I agree with you about the cutter rig...it's one fine way to go :-)

B.
__________________
btrayfors is offline   Reply With Quote
Old 25-02-2011, 07:04   #26
Registered User

Join Date: Jun 2009
Boat: Elan 37,Racing version
Posts: 42
Re: Radial counterpoises work

Quote:
Originally Posted by fijisails View Post
...It is about time that someone took a proven system and bundled it into a package that is easy to install, inexpensive and works very well. I installed a KISS last year on my boat and have enjoyed many thousand mile contacts and use it daily with winlink/sailmail. Once we were in the Marquesas and the Hawaii station was so busy I connected up to a winlink station in New Zealand with a fast baud rate, that was with an Icom 802 and an AT-140 tuner...
Good afternoon.
Your comment is of geat interest to me as It looks like if you have very strong contacts without any loop.I also have the same configuration as yours and do connect myself nearly everyday day via Airmail /PactorIII to the Winlink 2K network.
Bill ( thanks btrayfors ) has recently made my education on this grounding subject and thanks to him I will by one KISS-SSB.
Just one question to benefit from your experience.
I suppose that your transceiver is also connected to your AT via the Icom OPC-1147/N control cable.
Have you left the little additional green wire (which comes in parallel to the 4/6 pin connector) of that cable connected on one side to the ground screw of the transceiver and on the other side to the ground screw of the AT as per Icom diagram or have you disconnected it?
Thanks in advance fyr.
Cheers.
ON3CHD
__________________
ON3CHD is offline   Reply With Quote
Old 25-02-2011, 09:22   #27
Registered User

Join Date: Jan 2010
Posts: 6
Re: 'KISS' SSB Ground

When I installed my KISS-SSB counterpoise I was told to not connect the little green wire coming out of the control cable at the tuner, but to just tape it off. From the radio to the tuner there is already a common connection two other times, once in the shield of the coax and again in the DC negative lead in the control cable. The idea is to not initiate DC negative to the counterpoise/ground side of the tuner but to only connect the KISS-SSB to that lug. This eliminates a lot of potential RF running through the DC negative through-out the boat. My signal greatly improved when I went from the old copper and bronze plate to just using the KISS-SSB. I do a lot of net controlling and I can not tell you how many people have seen my signal strength and clarity improve and then went out and changed over to the KISS, but it has been a lot and I have seen their signal improve also.
I don't know if people know this, but Icom has stopped making the 710, since the M802 has been so popular for a few years now they figured why should they keep making the 710, which is a good radio too, but doesn't have all the bells and whistles like the M802.
__________________

__________________
fijisails is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
KISS - SSB Ground CAELESTIS Marine Electronics 28 02-07-2010 15:09
SSB Ground CAELESTIS Marine Electronics 10 26-03-2009 13:48
SSB - where can my ground plane be? esper General Sailing Forum 1 25-03-2009 10:25
SSB Ground phorvati General Sailing Forum 2 03-04-2006 12:12
ssb ground davemaskell Marine Electronics 17 02-12-2005 19:47



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 04:10.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.