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SoonerSailor · 17-02-2011, 18:05

The Icom 7200 would be a very nice rig for a boat, I agree. But, only the front face is "weather protected". I don't know if the circuit boards are conformal coated, but I doubt it - though I don't know which marine radios have that feature either.

Still, in most installations these would not be issues.

CAELESTIS · 17-02-2011, 18:39

+1 for the KISS SSB. Forget all the 1950's voodoo, this thing simply works.

S/V Illusion · 17-02-2011, 20:34

Just a couple of comments which may clarify some common misunderstanding.
First, a counterpoise, regardless of its composition, copper strap or a wire bundle, will not make any difference in power output. It is about the efficacy of the radiation pattern of the antenna, not power.

Any proper counterpoise will work as long as it is has one of two things: a mirror image resonant length at the desired frequency or forms a capacitive coupling to "ground".

The other comment worth making is that one should not judge the efficacy of their installation by making contact with stations at varying distances. There are far too many variables and particularly the wide variation in ionospheric conditions day-to-day, week-to-week and location-to-location. Far better is to find another nearby boat or station you can use as a reference with which you can compare signals both instantaneously as well as over a period of time. Not only does this eliminate many variables but can provide a reference for judging the efficacy of any changes you make.

ON3CHD · 23-02-2011, 10:42

Hello to all,
Since a few weeks I have read (and learned from all of you...thanks) quite a lot about grounding.

My previous grounding system, which took me hours and hours

to set up, was fine as my correspondents were telling me that my signal was very strong.
As I have however to redo (corrosion on an original bad choice of material has done its work...) my whole grounding system I wish you could validate the options I am going to choose as efficient and for sure much less time consuming and cheaper that what I have done in the past.

The system is mainly composed of
- an ICOM Marine IC-M802
- an Icom AT 140 located in the aft lazaret just under the base of were the antenna is passing through the hull (the cable connecting the AT to the antenna isolated connector fixed to the hull is 40 centimetres long)
- an antenna which is a long wire (11 meters) + 2 isolators on both extremities hoisted with a spinnaker halyard when needed and mainly when at anchor.

My main objective = Airmail use for e mails.
If signal is strong enough and not too noisy (as this is one of my problem for the time being) I might in the future try some voice connections.
At this stage I also wish to emphasise that keel bolts are not easily accessible and I wish to avoid as much as possible that path for DC grounding the more that I also wish to avoid DC current from the sea to enter back the boat. Personally I am not really convinced by the introduction of capacitors on the line to block it as they also corrode.

Based on the fact that they are 2 grounding types i.e. DC grounding and RF grounding (also named counter poise) I intend

A) to connect my radio with a good copper cable (rear panel of the transponder box) from the point designed as an earth connector to the negative of one of my batteries for DC grounding
B) to connect a few cables (length to be determined in function of the main frequencies I have used in the past) to the groundnut from the AT 140 for RF grounding.

As per some excellent comments made by Bill (also active on this forum if I don·t mistaken myself) see http://forum.ssca.org/phpBB3/viewtopic.php?f=5&t=1177&p=7019&hilit=RF+GROUNDS+I N+THE+MARINE+ENVIRONMENT#p7019 I also intend to use for RF grounding some TV twin led.
Should all the above be validated by the GURUS I wish to know if I can leave all these cables into the aft lazaret as per comment made in this forum by John Drake or if I have to extend them as much as possible in wish case due to some lengths I will have to give them an L or U form inside the boat.

Thanks to all for any comment on this.

Cheers.

ON3CHD

denverd0n · 23-02-2011, 11:45

Perhaps I am not understanding, but it sounds like you plan to use BOTH wires that are cut to length for the frequencies you want and some TV twin wire for your counterpoise. You do not need both. Bill just uses the TV wire as an easy way to get two wires in one compact package.

If you have only a couple of frequencies that you intend to use then a piece of wire cut to 1/4th wavelength for each frequency is all the counterpoise you need. Stretching them out as much as possible is best. An "L" or "U" in the wire is not a big problem.

Another alternative that is quick, easy, and usually works very well is a piece of copper strap to the nearest bronze through-hull.

ON3CHD · 23-02-2011, 12:37

Thanks fyr.
As english is not part of my 3 first spoken languages I might have mixed up a few concepts for which I do apologies.
See my answer in red in your text.

Quote:

Originally Posted by denverd0n

Perhaps I am not understanding, but it sounds like you plan to use BOTH wires NO that are cut to length for the frequencies you want and some TV twin wire for your counterpoise. You do not need both. Bill just uses the just 5 TV wires for 10 frequencies and because they seem very easy to use TV wire as an easy way to get two wires in one compact package this is precisely what I find interesting.

If you have only a couple of frequencies that you intend to use then a piece of wire cut to 1/4th wavelength for each frequency is all the counterpoise you need. Stretching them out as much as possible is best. An "L" or "U" in the wire is not a big problem.

Another alternative that is quick, easy, and usually works very well is a piece of copper strap to the nearest bronze through-hull.It is true that I have one about 50 centimeters far from the AT groudnut but how to fix that strap to such a seacock? I cn·t solder it where it is located due to space problems.

Cheers
ON3CHD

ON3CHD · 24-02-2011, 03:01

Quote:

Originally Posted by denverd0n

Another alternative that is quick, easy, and usually works very well is a piece of copper strap to the nearest bronze through-hull.

By the way just to make sure that I did understand the papers I have read when you refer to a through - hull connection you are refering to a DC grounding and not an RF grounding?
Am I correct?
If not then I will have to go back to school !!!
Thanks.
Cheers.
ON3CHD

denverd0n · 24-02-2011, 05:51

No, I am talking about RF grounding. With a copper strap to a bronze through-hull, the ocean becomes your counterpoise.

As for connecting it, you can fold the copper over and into a little triangle at the tip, and then punch a hole in it and attach it to a bolt or screw.

ON3CHD · 24-02-2011, 10:11

Thanks very much fyr.
Before starting my home work can you also tell me if in your opinion the idea of connecting the ground plug of the radio itself to the - of one of my batteries for DC grounding is a good way to go?
Thanks.
Cheers.
ON3CHD

btrayfors · 24-02-2011, 12:20

ON3CHD,

DenverdOn has given good advice. Do not connect your RF ground to your boat's DC ground. Further, do NOT connect a ground to the radio itself. That can create ground loops, which are undesirable.

Let me make it easy for you.

Forget the wires.

Forget the copper straps.

Forget the thru-hull connections.

Forget everything you've read.

Just purchase the KISS-SSB radial ground system ($145 on eBay) and connect it to the ground lug on your tuner.

It works extremely well.

You don't need anything else.

Good luck.

73,

Bill
WA6CCA

ON3CHD · 24-02-2011, 12:54

Quote:

Originally Posted by btrayfors

ON3CHD,

DenverdOn has given good advice. Do not connect your RF ground to your boat's DC ground. Further, do NOT connect a ground to the radio itself. That can create ground loops, which are undesirable.

Let me make it easy for you.

Forget the wires.

Forget the copper straps.

Forget the thru-hull connections.

Forget everything you've read.

Just purchase the KISS-SSB radial ground system ($145 on eBay) and connect it to the ground lug on your tuner.

It works extremely well.

You don't need anything else.

Good luck.

73,

Bill
WA6CCA

Hi Bill, thanks fyr which I was hopping.
I will follow your suggestion.
In the meantime as I am curious I wish to try your own system (when you visit your in laws...) for 4 frequencies which mean if I am correct 2 double TV cables to be cut to 1/4 wl that I can purchase easily here in Malta.I found your description really great

and I also know now ... no other connections than these cables or a KISS to the AT.
Should you not agree...please let me know.
Thanks very much for all these information.
73.
Claude
ON3CHD

btrayfors · 24-02-2011, 13:05

Quote:

Originally Posted by ON3CHD

Hi Bill, thanks fyr which I was hopping.
I will follow your suggestion.
In the meantime as I am curious I wish to try your own system (when you visit your in laws...) for 4 frequencies which mean if I am correct 2 double TV cables to be cut to 1/4 wl that I can purchase easily here in Malta.I found your description really great

and I also know now ... no other connections than these cables or a KISS to the AT.
Should you not agree...please let me know.
Thanks very much for all these information.
73.
Claude
ON3CHD

Bon soir, Claude...

Yes, the TV twin-lead works well, but so would any other 1/4 wave radial system. I actually made one up for the marine SSB bands some years ago out of 6-conductor AWG14 cable. It gives me six bands!!

In the past, I've used the TV twin-lead radial system in conjunction with a little MFJ manual tuner, located near the radio. It works pretty well, though is not optimum.

A better system, which I've tried on boats, is to use an UN-UN (unbalanced-to-unbalanced) "balun", designed for end-fed wires. Balun Designs, Inc. makes such a beast which will handle 5KW, I think. Very well made, waterproof, and about $80.

You place this UN-UN near the base of the random-length wire antenna, and connect the radials to it there. Then, you can use any length of coax to run to the tuner and radio. It works very well. The UN-UN converts the impedence at the base of the wire antenna to values which the tuner located near the radio can easily handle. Radios with internal tuners (like the Yaesu FT-900AT, the Icom IC-703, etc.) can handle these values very well, so you don't need anything else.

I've used the KISS-SSB system myself, and have installed it on a few client boats. Works great, even when there's no room to uncoil it. Liked it so well I became a dealer (disclosure!!). It's very well made, and includes several hundred feet of wire stuffed into a 10-foot long rubber hose, with a 4-foot length of AWG10 yellow wire to connect to the tuner ground lug.

Yes, you can improve on this ground by adding additional radials or other RF ground connections. But the KISS-SSB system works very well all by itself. And, believe me, unless you're willing to pay yourself only $10 an hour you can't possibly make one to match!!

Bon chance, mon ami

Bill

AfterHoursNLCT · 24-02-2011, 13:10

The people at KISS-SSB added 17 and 30 meters to my counterpoise at no extra charge.......LL

ON3CHD · 24-02-2011, 14:10

Quote:

Originally Posted by btrayfors

Bon soir, Claude...

Yes, the TV twin-lead works well, but so would any other 1/4 wave radial system. I actually made one up for the marine SSB bands some years ago out of 6-conductor AWG14 cable. It gives me six bands!!

In the past, I've used the TV twin-lead radial system in conjunction with a little MFJ manual tuner, located near the radio. It works pretty well, though is not optimum.

A better system, which I've tried on boats, is to use an UN-UN (unbalanced-to-unbalanced) "balun", designed for end-fed wires. Balun Designs, Inc. makes such a beast which will handle 5KW, I think. Very well made, waterproof, and about $80.

You place this UN-UN near the base of the random-length wire antenna, and connect the radials to it there. Then, you can use any length of coax to run to the tuner and radio. It works very well. The UN-UN converts the impedence at the base of the wire antenna to values which the tuner located near the radio can easily handle. Radios with internal tuners (like the Yaesu FT-900AT, the Icom IC-703, etc.) can handle these values very well, so you don't need anything else.

I've used the KISS-SSB system myself, and have installed it on a few client boats. Works great, even when there's no room to uncoil it. Liked it so well I became a dealer (disclosure!!). It's very well made, and includes several hundred feet of wire stuffed into a 10-foot long rubber hose, with a 4-foot length of AWG10 yellow wire to connect to the tuner ground lug.

Yes, you can improve on this ground by adding additional radials or other RF ground connections. But the KISS-SSB system works very well all by itself. And, believe me, unless you're willing to pay yourself only $10 an hour you can't possibly make one to match!!

Bon chance, mon ami

Bill

Hello Bill,
I was not expecting you taking so much of your time.
Thanks very much for all these details.
Have had a look at the UNUNS.
Very interesting .I suppose that the coax coming out of the beast will have to be connected to the antenna terminal screw from my AT 140 (which is 3 meters apart from my radio) and that no other connection ( i.e. the radio) has to be done?
Anyway thanks again for all the time devoted and tha good explanation.
73
Claude