Dynaplates

[davimack]

Does anyone have any experience with the Dynaplate Ground Plate, or their various equivalents, Newmar Ground Shoe, Wonderbar Ground Plate etc.??
I am about to redo my ground "counterpoise" on my SSB. Icom etc. suggest 100 sq.ft. of copper foil, where I would put it all, Goodness knows!!
Apparently one of these bars is the equivalent, but have not heard of any genuine users, for or against.
Any comments

Davimack
SV Odyssey

[camaraderie]

I had both a dynaplate AND the copper foil. Just threaded the 4" wide foil under the floorboards wherever it coulr go. 300 inches of the foil is 100 sq. feet. Can't really comment on the Dynaplate alone as we used both but had good output and reception. The D-plate is pooh pooed by many as unnecessary but I've also heard good comments from those using it exclusively. Bill Trayfors and Nonjy are the ham/SSB techies here and can perhaps lend a little more meat to this discussion!

[btrayfors]

Davimack,

IMHO, Dynaplates and their equivalents are the last resort of desperate men :-)

Or, more often, they "come with the boat".

Very seldom needed; not great, anyway; costly; much better alternatives.

What kinda boat?

Bill

[davimack]

Thank you for your replies. Boat is a Young Sun 35. A Bob Perry cutter, but very difficult to get under the floorboards for foil. Am going to lay foil on top of 2 watertanks and fuel tank, but that will only take about 30 ft. so felt the ground plate would be a great idea.

[sailboy21]

Came with the boat. Works great. No other counterpoise system other than about 15 feet of foil & copper water pipe used to link the tuner to the dynaplate, the engine and lifelines. 5 & 5 for 150 miles west of San Fran to Texas on 14.3.

[goboatingnow]

Having had boat Dynaplate and foil , you need the foil in my experience

[Joesaila]

Came w the boat...lots of green osmosis/corrosion or reaction stuff on the wires so I replaced wires and dynaplate at the suggestion of my marine electrician and while it looks a lot better and has to be carrying current more efficiently I'm not certain it was worth it... My zincs seem to be almost totally gone at the end of my 5 month season. Though I had not heard of the copper foil I wonder if that might make a difference? "A boat is a hole in the water..."

[btrayfors]

davimack,

Lotsa ways to skin a cat. The "100sq ft of copper" is an urban legend...repeated in many, many places but nevertheless nonsense as is the impreachment that "wires won't work".

What is true is that you need some sort of effective RF ground to serve as the "other half" of the antenna system. This can be as simple as a wide copper strip run from the tuner to the nearest bronze thru-hull. The thru-hull should not be otherwise bonded to the DC system or, if it is, it's a good idea to put some sort of DC-blocking device inline, like a number of parallel capacitors bridging a narrow gap. Type X7R Monolithic Ceramic capacitors, 0.15uF, $0.91 each, Digi-Key part number P4911-ND would do the trick nicely. See Stan Honey's excellent article on grounding here: Grounding

Also, see my post on "RF grounds in the marine environment" here: SSCA Discussion Board :: View topic - RF GROUNDS IN THE MARINE ENVIRONMENT

I don't know the YoungSun 35, but there may be other ways to fashion an effective ground as well, including: stainless steel rub rails (like the IP's have), pushpit/lifelines/pulpit complex, radials under the decks, aluminum toerails, etc., etc.

But, the simplest and pretty effective way to do it is just to run a wide copper strip to the nearest thru-hull. You can add to that later if needed.

Bill

[davimack]

Originally Posted by camaraderie

I had both a dynaplate AND the copper foil. Just threaded the 4" wide foil under the floorboards wherever it coulr go. 300 inches of the foil is 100 sq. feet. Can't really comment on the Dynaplate alone as we used both but had good output and reception. The D-plate is pooh pooed by many as unnecessary but I've also heard good comments from those using it exclusively. Bill Trayfors and Nonjy are the ham/SSB techies here and can perhaps lend a little more meat to this discussion!

Forgive me, but am I not right in thinking that 300" of 4" foil is only 1200 sq.in. which is 8.33 sq.ft., but maybe you meant 300' of the foil. If not then maybe there's hope for me yet. I can easily get maybe 30' into the bilge etc. maybe that and a Dynaplate if necessary would do the job.
Davimack

[sailboy21]

I briefly mentioned it in my first post, but I'll expand little on the copper water pipe. If you want the most durable, and RF friendly connection possible (i.e. one that doesn't turn to green dust in a couple years) get 1/2" flexible copper waterpipe. (2" circumference) Route it where you need it and then find battery lugs that fit snug inside the end. Crimp down lightly to hold the lug in place and then get out a propane torch and solder it in. What you end up with is a super heavy duty RF friendly connection that will last forever. The copper foil is far too subject to failure. I only use it where flexibility is needed. I use the copper foil, but I think a lot of the reasoning behind it is no more than black magic. Take a look at the wiring to the ground lug on your tuner... hmm 18 gauge wire. Thats funny, wonder why the manufacturer didn't use a chunk of foil?