Why are these used and why is bigger better? Sorry to be such a novice. I have found this forum to be one of the very few that I can ask such simple questions.
Dynaplate
- Thread starter banjoey
- Start date
Big plates are big grounds. It's a SSB requirement essentially. That's my understanding. HF loves grounding. Cell towers use hundreds of feet of the stuff in a radial pattern. I know a guy that buried a bronze bathtub for the grounding.
Which was just as well, nasty devil never used the tub anyway.
My last ground plane was 550 feet long. (In dirt). So those smaller plates are probably a trade-off anyway, no way to put that much ground in the drink. Trail it maybe. Plus the things get eat up by electrolysis fairly quickly, just more plate to donate.
Just my thought..
Which was just as well, nasty devil never used the tub anyway.
My last ground plane was 550 feet long. (In dirt). So those smaller plates are probably a trade-off anyway, no way to put that much ground in the drink. Trail it maybe. Plus the things get eat up by electrolysis fairly quickly, just more plate to donate.
Just my thought..
This is a big point of contention in the sailing community. Dynaplates are the counterpoise ground for your HF radio antenna (assuming you are not using a dipole) The grounding currents are SURFACE currents that are ALSWAYS withing 1/2" of the water surface. If you use the keel as an HF ground you are not doing much in the way of HF grounding as the current has to push into the water to get to the keel. It does not like to do this and your signal strength will suffer. One common belief is that more grounding surface is better. True but the ocean is a pretty large surface and you are going to have to tie into that at some point so why bother lining the boat with foil just so you can tie into the water using a capacitor action method? Lots of work and no imporvement over other ways of getting current to ground. The Dynaplate is supposed to give you lots of surface area in contact with the water which is OK but not needed. Articles I've read and my own experience is that a simple braided cable over the side provides all the RF ground you can get.
The key point is that the braided cable has to be bare at the surface of the water and the location it enters the water should be close to the antenna feed. You want braided due to HF currents being only on the surface and braided has much more surface than a wire.
The key point is that the braided cable has to be bare at the surface of the water and the location it enters the water should be close to the antenna feed. You want braided due to HF currents being only on the surface and braided has much more surface than a wire.
A dynaplate as mentioned above is a radio ground. The nodules on the dynaplate increase it's surface area by many times what a flat plate the same size would have.
It's been a long time, but there is something about the surface area of the ground plain being related to wavelength, I believe.
Anyway, an unpainted ground is necessary for hf radio and a dynaplate is by far the most efficient available.
It's been a long time, but there is something about the surface area of the ground plain being related to wavelength, I believe.
Anyway, an unpainted ground is necessary for hf radio and a dynaplate is by far the most efficient available.
I have had three cruising boats; 1 X steel, and two FRP. obviously there is no need for a dyna plate on a steel vessel as the hull it's self is the ground. the two Fiberglass boats I've owned I had fitted with Dyna Plates for SSB ground. I used 3'' copper foil to connect the Dyna Plate to the SSB. with this set up, I had good reliable [atmospherics allowing] comms. once communicating with a fellow cruiser, in the Galapagos, whilst transmitting from NE coast of Australia. the D/P is low maintenance with a regular, simple scrub [wire brush] to expose the bronze they work well..they must not be painted when Anti-fouling is applied to hull!.
If you are thinking of needing an HF ground, I'd look at the KISS-SSB ground plane instead of the dynaplate. It's much easier to install and works great.