Ssb Copper Screen

[SoonerSailor]

I think copper screen would corrode very quickly. If you could hermetically glass it in, perhaps it would last. I would not recommend it myself.

Nothing wrong with running a 20’ copper strap to a keel bolt. If a strap that long is adjacent to the hull and so sea water on its run to the keel then it is probably doing almost all of the counterpoising needed whether actually attached to the keel bolt or not.

If you want to make some improvement, run more strapping along the hull in different locations. Or even some lengths of insulated wire strewn about those dark spaces next to the hull - and also attached to the tuner ground lug.

[hellosailor]

a64-
The (urban myth?) about Dynaplate is that since it is sintered bronze, there's a lot of water trapped in it, and if a lightning strike flashes through the Dynaplate, all of that water, trapped in the plate, will superheat and cause a steam explosion. Destroying the plate and, possibly, blowing a large hole in the boat, as if a limpet mine had gone off next to the hull.
So it is not just about blowing out a thru-hull, or the bolts anchoring the plate on, but there are folks who say the whole thing is a bomb waiting to go off. And if you tie the lightning ground to it, that's a good way to find out. But as a radio ground...I'd think unlikely.
Easy enough to unplug that, along with the antenna and radio power leads, when not needed or when lightning is in the area.

As HyLyte mentions, individual performance is going to vary from boat to boat. Even the ARRL advises ham operators that EVERY BOAT IS DIFFERENT, even sisterships right off the same line, and exactly how all the pieces of the rigging are coupled, and how well grounding and other issues work, needs to really be done experimentally on each boat.

Yes, there are generally good starting points, but there are also a lot of bogus gadgets that keep coming onto the market, and a lot of subjective reporting--since objective measurements of long distance contacts are kinda hard to compile.

Sooner-
For any untinned copper that is used for radio purposes? Coupla coats of varnish or white bilge coat or any similar paint will seal it up and protect it pretty much forever, without affecting the performance at all. If someone had only thought to paint the Statue of Liberty, it wouldn't be that shabby green color either.(VBG)

[ka4wja]

David,
1) First off, I will add more later...I'm in the middle of something now....so sorry about being brief..


2) Next, what Jim wrote here is VERY good!!

Originally Posted by 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

Bottom line here:
Anything will work...even no "antenna ground" at all, will still allow your radio to work...
It is all a matter of degree...i.e. How Well Does it Work??
Versus how much money/time do you wish to invest, versus your increases in performance...
(just do NOT waste $150 on a KISS-Ground...you can make one that is better, for < $5!!)



3) Good 'ole Gordo (Gordon West) did some real-world tests a decade and a half ago (maybe even close to 20 years ago??), and found that a direct sea water connection for your antenna ground works best...compared to "capacitively-coupled ground screens", it was substantially better, and even significantly better than random wire radials, etc...
Gordo, also found that as long as you make a low-impedance connection, the exact underwater part of the sea water connection wasn't critical...Assuming you use a low-impedance connection to a sea water connection (such as a wide copper strap), there is not much improvement in using commercial "Dynaplates" versus a clean underwater bronze thru hull....and there is no evidence that a "sintered-bronze" plate is any better than a solid bronze plate....or capper plate, etc...
BUT...


But, the "Dynaplates" are well designed, tapered, drilled, and easy to install....so, for those of us who have Marelon thru-hulls, a Dynaplate is a good choice....
For those with an underwater bronze thru-hull, that's close to the tuner (< 6' - 8' away), connecting the tuner to this, with 3" wide copper strap, is usually all they need...




Again, there is a lot more to all of this....but, I don't have the time right now...maybe later...

'Til then, have a look at the stickies here..
http://www.cruisersforum.com/forums/...tc-198305.html

http://www.cruisersforum.com/forums/...tc-133496.html


And, of course, the Sailmail Primer..
https://sailmail.com/wp-content/uplo...2/smprimer.htm



Fair winds.

John

[Frankly]

That Dynaplate A64 is using came from me. It was one of the jumbo sizes and worked fine (Winlink, Sailmail, ham, and marine). I just decided to try my Centerboard Cable Tube(SS) and it worked just as well. Don't have to scrape the growth on the CB tube, so off came the DP and on to the next happy IP owner. A64 did get the deal of the Century.

As to lightning dissipation I have a similar sized copper plate sitting just fwd of the mast step. The difference is, it is held in place with 4 ea 1/2" silicone bronze bolts (soldered to the plate, that was fun) and all 4 bolts are connected to the mast base with 1/0 cable (2 ea crimped and soldered). My theory about the exploding DP lore is that if you only have one 1/4" or 5/16" bolt that just don't cut it at 10,000 Amps, but it is only a theory.

Frankly

[CampDavid]

Thanks to all. I can get two small 2” x 6” Dynaplates for a good deal. Easy to mount very close to the tuner. Would that be as good as a single thru hull

[ka4wja]

Just some more info / clarification...


EDIT:
PLEASE note that NONE of this is about a Lightning Ground!!
This all about an antenna ground!!
Lightning grounding is a whole 'nother discussion!! (And one that I'm very well versed with!)
And, FYI, do NOT use a sintered ground plate for lightning ground...it is clearly stated in the Guest literature and warnings....
If you wish to know more about this, start a new thread!!!


1) Jim's comment about my experience with Dynaplates is a bit off....
They are great (but pricey!)...
But, the Dynaplate "sintered" bronze plate, really don't provide you any improvement versus a "solid" bronze plate....the "sintered" aspect might make a difference in the lab or on paper, but in the real world, it really doesn't...
And, that is the point I make about "Dynaplates"....they're great, but pricey, and are about the same as the same sized "solid" bronze plate...
(but, if you've priced 1/2" thick solid bronze lately, a 18" x 6" piece is damn pricey as well...)


2) As I wrote previously, this is all explained in the "stickies" and in the Sailmail Primer....
http://www.cruisersforum.com/forums/...tc-198305.html

http://www.cruisersforum.com/forums/...tc-133496.html

https://sailmail.com/wp-content/uplo...2/smprimer.htm

But, in a nutshell, also as I wrote previously...."anything" metallic or RF conductive will work to some extent....so, it's all a matter of degree...

In these circumstances (where we are going to use the sea water as our antenna ground), it is very important to make as direct / close connection from the tuner's ground lug to the sea water as possible....and/or use as much RF Conductive "surface area" (such as the copper strapping) in as close proximity to the tuner as possible....
(but, fyi, don't forget the antenna starts right at the tuner, actually the tuner IS part of the antenna, so placing the tuner into the bowels of the bilges, would place the antenna down there too....so, a happy medium needs to be selected!! And, in that vein, please remember what I wrote earlier....it's all a matter of degree!!)

You see, the copper strapping is used as a low-impedance connection from the remote tuner, to the sea water connection (Dynaplate, bronze thru-hull, etc.), using the sea water as the "antenna ground" (although the copper strapping does also function as part of your antenna ground)....this is not using the copper strap as your antenna ground, but actually using the sea water as the antenna ground...the copper strapping is basically the way you're connecting to the "sea water ground"....

If you want to explore using an artificial ground / counterpoise, you can of course simply use regular wire!!! No copper strapping needed!!

BTW, a few years back I did a RF impedance (inductance) comparison (and it is still posted over on the SSCA discussion boards) between a simple 2" wide copper strap and a HUGE 0000ga round copper wire, and calculated the 2" wide copper strap had less than half of the inductance of even that huge round wire....and 3" copper strap was of course even lower!!! (but, I'm a "radio nut"...I use 6" wide copper strapping!!!)


3) FYI, you may notice that I write copper strap / strapping?? And, not talking about "foil"??
The reason isn't because foil wouldn't work....it's because "foil" is so thin / flimsy that it tears too easily, it corrodes too quickly (and while you could paint it / coat it, it's kinda a waste of time...better to spend the $ on strapping)...

If in the US, I recommend Georgia Copper...actually even if not in the US, I still recommend them!! GREAT guys to do business with and they sell REALLY nice copper strapping!!

FYI, 0.012" thick, 3" wide is okay for most applications, and most sailors will find this easy to work with and long-lasting....but I do tend to recommend 0.022" thick, 3" wide strapping...

https://www.gacopper.com/
https://www.gacopper.com/012-CopperStrap.html
https://www.gacopper.com/022-CopperStrap.html
https://www.gacopper.com/Link.html

FYI, I painted / covered my 0.012" thick, 3" wide copper strapping....and it's still in great shape....but I didn't bother to cover/paint my 0.022" thick, 6" wide copper strapping, and almost 15 years on, and it still as solid as day one!!
Just a quick spray with even cheap paint, on the strapping before you install it, will keep it solid for decades....(just be sure to clean off all the paint off from the connection points!! or just don't paint the ends...)

Also, as I write in the stickies....I recommend a conductive grease on the ground connections in the bilge....whether to a keel bolt, a bronze thru-hull, or a gold-plated Dynaplate bolt...using a nice dallop of Penatrox-A conductive grease will keep this connection clean and dry for years....

Originally Posted by ka4wja

David,
1) First off, I will add more later...I'm in the middle of something now....so sorry about being brief..


2) Next, what Jim wrote here is VERY good!!

Bottom line here:
Anything will work...even no "antenna ground" at all, will still allow your radio to work...
It is all a matter of degree...i.e. How Well Does it Work??
Versus how much money/time do you wish to invest, versus your increases in performance...
(just do NOT waste $150 on a KISS-Ground...you can make one that is better, for < $5!!)



3) Good 'ole Gordo (Gordon West) did some real-world tests a decade and a half ago (maybe even close to 20 years ago??), and found that a direct sea water connection for your antenna ground works best...compared to "capacitively-coupled ground screens", it was substantially better, and even significantly better than random wire radials, etc...
Gordo, also found that as long as you make a low-impedance connection, the exact underwater part of the sea water connection wasn't critical...Assuming you use a low-impedance connection to a sea water connection (such as a wide copper strap), there is not much improvement in using commercial "Dynaplates" versus a clean underwater bronze thru hull....and there is no evidence that a "sintered-bronze" plate is any better than a solid bronze plate....or capper plate, etc...
BUT...


But, the "Dynaplates" are well designed, tapered, drilled, and easy to install....so, for those of us who have Marelon thru-hulls, a Dynaplate is a good choice....
For those with an underwater bronze thru-hull, that's close to the tuner (< 6' - 8' away), connecting the tuner to this, with 3" wide copper strap, is usually all they need...




Again, there is a lot more to all of this....but, I don't have the time right now...maybe later...

'Til then, have a look at the stickies here..
http://www.cruisersforum.com/forums/...tc-198305.html

http://www.cruisersforum.com/forums/...tc-133496.html


And, of course, the Sailmail Primer..
https://sailmail.com/wp-content/uplo...2/smprimer.htm



Fair winds.

John

Here are some pics of my SSB install / Dynaplates / 6" wide copper strapping / Nav Station, etc....on my current boat...(installed in 2004, and still going strong!)

4706601





4705407




AIS Transponder




Nav Station







I hope this helps clear things up??
But, if not....please have a look at the stickies up top...and the links in them....that is what they are there for...

Fair winds..

John

[ka4wja]

David,
Actually, they'd be better than (or at worst, equal to) your thru-hull...just make sure they are underwater at most times / points of sail, and you'll be fine....

Originally Posted by CampDavid

Thanks to all. I can get two small 2” x 6” Dynaplates for a good deal. Easy to mount very close to the tuner. Would that be as good as a single thru hull

And, they'll be easier to keep clean and barnacle-free...


Just use some nice copper strapping to connect 'em, and you're good-to-go!!




Good luck...

And, please read my latest post above, as well as those stickies, and of course the Sailmail Primer!!

John

[transmitterdan]

Originally Posted by CampDavid

Thanks to all. I can get two small 2” x 6” Dynaplates for a good deal. Easy to mount very close to the tuner. Would that be as good as a single thru hull

Yes, just as good.