Ssb Copper Screen

[CampDavid]

There is a whole lot of info on CF regarding SSB installation and in particular on RF ground plane.

Simple question

I am thinking of using a large pure copper mesh or screen mat. Soldering a 4” wide copper strap to the mat to connect to the AT 140 and to thruhull

Will this work? If so what type of screen or mesh should I use? I plan to coat it with gelcoat after installation

Fletch

[Jim Cate]

Yes, it will work. But, so will using the same copper strap and connecting it to a metal through hull or a keel bolt.

There is so much overthought and overkill on this subject that it is often hard to find out what will actually work in the real world. The strap to a keel bolt has been working for us for many years. IIRC your Bene has an iron keel with accessible bolts... that would likely be pretty easy to work out.

Jim N9GFT/VK4GFT

[CampDavid]

It would be close to 20ft from the AT 140 to the keel bolts. Is that not an a little far away

[hellosailor]

You can run standard woven tinned copper "ground strap", the flat braid, from the tuner to the keel bolt. Or, you can probably find 3-4" wide copper roofing foil and just run a length of that, then paint over it to bond and seal it to the hull.

Something to bear in mind is that anything metal running against the hull (as that foil or braid would be) is capacitively coupled to the seawater on the other side anyway. At radio frequencies, it practically *is* in the ground.

Not worth worrying about embedding large areas of copper screening, IMO.

If you really wanted a radio ground right "at" the tuner? You could always consider bolting up a Dynaplate on the outside of the hull, as close to the tuner as possible. The Dynaplate is sintered bronze, porous and with an incredible large amount of surface area directly in the seawater as a result of that. No long wiring run needed.

[Jim Cate]

Originally Posted by CampDavid

It would be close to 20ft from the AT 140 to the keel bolts. Is that not an a little far away

Yes, likely longer than optimum. Is there a through hull nearer?

Jim

[CampDavid]

Is the Dynaplate , I assume the big one, enough as a stand alone? They are pricey, the big one, I assume the smaller ones are more for dc grounding

[Jim Cate]

IIRC, KA4WJA, one of the CF HF gurus has said NOT to use Dynaplates for RF grounds. You might look through his voluminous posts on HF installations... his advice is well grounded (!).

Jim

[CampDavid]

I had a Kiss on my rig in my old boat. Never got the performance I expected. This time I want to use a proven system. M802 At140 and a dedicated alternative backstay type antenna Coated life line.

[Cheechako]

Gel coat over screen will likely end up in a mess of flaking gel coat. It's very brittle and flaky when not reinforced.

[CampDavid]

I was thinking of roughing up the existing gelcoat. Cleaning it up with acetone and then placing the copper mat in place and gel coating it against the hull.

[a64pilot]

Originally Posted by Jim Cate

IIRC, KA4WJA, one of the CF HF gurus has said NOT to use Dynaplates for RF grounds. You might look through his voluminous posts on HF installations... his advice is well grounded (!).

Jim

Why not a Dynaplate? I can see the argument that they aren’t necessary, that pretty much the same can be accomplished much more cheaply with a thru hull, surely there is nothing “wrong” with a dynaplate?

[transmitterdan]

Most types of woven wire mesh are very lossy because the wires only make casual contact. The wires are not bonded where they criss-cross.

Just use a double or triple wide run of 4” strap from the tuner straight to the thru-hull. The copper mesh will not really help. Also, put lots of ferrite on the coax close to the tuner. Same goes for the tuner control/power cable.

If you want to form a ground plane inside the boat then laying down a grid of 4” wide copper strap on 12-16” centers will work well. Solder them together where they cross each other. Painting (or gel coating) over them will probably not last.

There is nothing wrong with a dyna-plate. That is also a good solution if you put it right up next to the tuner but below the water line. The installation will be neat and it will work.

Some one has a cousin who knew a guy who drank with another guy that saw a you-tube video about a dyna-plate exploding during a freak lightning storm. To date I haven’t seen any evidence this old wives tale is true but for sure someone will pop in here and swear that it is.

KISS works because it is so lossy that the radio never complains. Not recommended in my book. YMMV though.

[a64pilot]

Im my case the best place to put the tuner was pretty far from a thru hull.
I looked at using the rub rail and other means of obtaining a counterpoise, but lucked into a member that was local to me that pretty much gave me a large Dynaplate, next bottom job I was able to mount it directly underneath the tuner for the shortest run possible, so I think there are use cases for a Dynaplate, just don’t buy into the silliness that it being made from little beads does anything special.

Lightning can do anything to include blowing holes directly into the fiberglass, I’m sure it can blow off a Dynaplate, or blow out a thruhull for that matter.
Only thing I’m sure of with lightning is that all bets are off, anything is possible, and it often defies logic.
I saw it strike the ground right near the pitchers mound in Carrabelle Fl. On a field that had tall light poles, a fence around it and of course the tall metal fence backstop and it went for the ground?

[AfterHoursNLCT]

An interesting paper from Gordon West:

https://www.google.com/url?sa=t&sour...NhelJeqvqknex3

[svHyLyte]

A Disclaimer: I know very little about radio electronics.

What I do know is what works for us. Our system is an old ICOM M-700 working through an AT-120 Tuner with an insulated back-stay antenna. Our "ground plane" is two sheets of copper foil, approximately 26 Ga, measuring 12" x 40" adhered to the hull on either side of our rudder post. They are not coated. Both are attached to legs of a Y-connector with the third leg connected to the tuner with a reasonably heavy cable about 6 feet in length. The connection to the foils are made with ring connectors through which an approximately 1/4" dia. copper bolt passes with approximately 2" diameter copper cut washers under the bolt head and nut on either face of the foils.

With the foregoing, we have had good performance with the radio up to and including the ability to converse with another yacht, situated in the Canary Islands, from our home port in the Tampa Bay area some while ago.

At one point I let a supposed "expert electrician/radio tech" convince me that I needed a large Dyna-Plate for the installation to "improve" its performance pursuant to a planned trip to the EC. After having that installed and connected, we found no measurable improvement in our transmissions such that, when the copper foil strap connecting it to the Tuner failed several years later, we simply removed the strap entirely.

Copper foil can be found at "basiccopper". As the offside/bottom edges of our foils are getting pretty ratty at this point due to moisture and age so their replacement is on my ever growing spring "to-do" list.

FWIW...