Icom m802 Rf grounding

[btrayfors]

Bill,

I think the copper strap to the nearest standalone bronze thru-hull might be preferable, because of all the other stuff connected to the built-in grounding system.

What we're trying to achieve, here, is an RF ground....not necessarily a DC ground....which is independent of other grounding systems on the boat: DC ground, lightning ground, corrosion grounding system, etc. This limits somewhat the RFI problems, i.e., interference with other electronics on the boat or interference FROM other electronics on the boat.

Anyway, give it a try first and see what you get.

Bill T
WA6CCA

[muttskie]

Originally Posted by btrayfors

Bill,

I think the copper strap to the nearest standalone bronze thru-hull might be preferable, because of all the other stuff connected to the built-in grounding system.

What we're trying to achieve, here, is an RF ground....not necessarily a DC ground....which is independent of other grounding systems on the boat: DC ground, lightning ground, corrosion grounding system, etc. This limits somewhat the RFI problems, i.e., interference with other electronics on the boat or interference FROM other electronics on the boat.

Anyway, give it a try first and see what you get.

Bill T
WA6CCA

Thanks, Bill.
This was what I thought. It's easy enough to go this route and if I have issues it would be very simple to change to the built in ground plane and try that as an alternative. Your comment about RF ground vs DC ground is on point.
Thanks again,
Bill Petras

[Far Star]

Hi Bill T
Is it ok to use a stainless steel thru hull fitting for the RF ground with the copper strap, instead of bronze which sèems to be mentioned alot.
I looking for temporary alternative until I next pull my yacht out of the water to fit my dynaplate. I have 2 fittings close by which I wanted to bond together with the strap.
Cheers
Terry

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[btrayfors]

In most cases it's not a good idea to mix metals. You'd probably get away with it, but I wouldn't do it.

Also, save your money....it's rare that a Dynaplate is required and as time passes they become less and less effective.

I'd probably try a radial system first, either the KISS which is very easy to install or your own radials constructed from insulated wire. Not sure what else is available on your boat for a RF ground/counterpoise, but some boats have metal toe rails or rub rails, a metal rudder post, the pushpit/pulpit/lifeline complex, etc. any or all of which can be used for an excellent RF ground.

Bill

[nhschneider]

Shortly after we bought our boat in '96, my family and I took off on a one-year, 10,000-mile cruise. I was active on many of the HF and SSB nets and eventually became a net controller as people frequently commented that my signal was 'booming' in, even at significant distances. It wasn't until years later that I had the occasion to actually inspect how the tuner was grounded and to my surprise I found a narrow, thin aluminum strap going from the tuner to one of the small winches on deck - that was it. Now my tuner is grounded using the KISS system but I don't think my signal is any better. Frankly, despite what the engineers say, I think it's just Black Magic.

Fair winds and calm seas.

[Far Star]

Thanks for the great Reponse Bill , much appreciated.
I obviously don't know much about Rf grounding. I thought you needed to be contacted to the sea water to get a good grounding. Now I am really confused.
Can I connect to my lifelines and stanchions and davit metal work
Terry


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[btrayfors]

Yes, you can.

It's one of those urban myths that you necessarily have to make contact with seawater. Yes, there can be advantages in some cases ... like in bleeding off static electricity for quieter reception ... and in helping to use the conductivity of seawater to collect RF to be fed back to the transmission point.

HOWEVER, radials by themselves work very well. And, elevated radials work better than buried radials or those just lying on the ground. Hams have known this for years.

As the previous poster noted, most anything can be made to work pretty well. Yes, by all means tie in the s/s lifelines/pulpits/etc., either as supplementary or primary elements for RF grounding.

Bill
WA6CCA

[Far Star]

Bill
Does that mean I can run the copper strap direct to the closest pulpit attachment which connects via the lifelines to pushpit around the yacht to create a good RF grounding? What about copper to s/s attachment? Back to to the dissimilar metal issue
Much appreciated Bill
Terry

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[btrayfors]

Terry,

Yes, you can do that. You can even use a heavy-ish wire...not necessarily the copper strip (busting yet another urban myth about wires in RF grounds :-).

No problem with dissimilar wires here....there's no immersion in seawater :-)

Bill

[Far Star]

Bill
What do you think of the Kiss - ssb counterpoise system
Terry

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[btrayfors]

It's fine in most installations. Very easy to install, very robust. Works well. Not the absolute best counterpoise you can think of, but a pretty good compromise for many boats.

(Disclosure: I'm a dealer for the KISS....the ONLY product for which I am a dealer. And, I use one on my own boat. Have installed dozens of them on client boats....no complaints!)

Bill
WA6CCA

[BocaIII]

Originally Posted by btrayfors

Terry,

The techie you spoke to was correct: ground the AT140 tuner ONLY. No RF ground needed at the main transceiver box, and it could well cause a ground loop.

Bill
WA6CCA

Listen to Bill...He knows what he speaks!
As a ham radio operator myself for over 50 years, you either learn the theory and mathematics or by experience the difference between DC Grounds and RF Grounds.....you want a RF Ground.

Jack
W4GRJ

[SoonerSailor]

If you dont want to spend $150+ on a KISS, just attach 14' of tinned insulated wire to the tuner ground instead, and put it where you would have put the KISS. You should get the same result with an outlay of few dollars.

Use a ring terminal on the tuner end, and seal the far end to prevent moisture intrusion.

If you want to make it even better than the KISS, make several of these wires of differing random lengths and run them into different locations in the bilge, all attached at the tuner lug.

If $150+ is no big deal but time and effort is, then go ahead and give the KISS a shot.


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[Far Star]

Thanks for all the info.
I think I will give my lifelines and stanchions ago first then get a Kiss if not happy.
However would the Atu have to be mounted above the lifelines to be affective?
Terry

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