Dyna Plates

[a64pilot]

I had a member sell me one for next to nothing cost wise, it is a large Dyna Plate.
Boat is hauled out now for a bottom job, now is the time to fit it. I should be able to have it mounted close to where the tuner will be.
Question is, is a Dyna Plate the best Counterpoise? I do not have nor can or will I fit a large copper mesh net into the boats hull. I had intended to use the SS rub rail until I got the offer for the Dyna Plate.
It has been my understanding although this is old data that most anything will work, but the standard by which all are measured is the Dyna Plate?

So what I am asking is, is there something better than a Dyna Plate? If you had essentially a free Dyna Plate and the boat on the hard, would you install it?
If not, why not? I can deal with the constant scraping of the thing, I'll be diving the boat often anyway

[CSY Man]

I installed a "generic" Dyna plate.
Worked good, lasted a long time.
Did not scrape much, 5 minutes at each haul-out, steel brush, not a scraper.
Got great range on the SSB, did frequent radio checks with Lima Radio (Peru) from my dock in Fort Lauderdale.

[Goudurix]

Hi A64 pilot,

Before installing a dedicated dynaplate I used the following RF ground system:

- S/S lifelines and pushpit tied via copper tape to antenna tuner ground lug
- 2 sets of precut radial wires bundles (cut for 40m-20m-17m-15m HAM bands but could also be to marine SSB bands)running both sides strapped to toerail with tie wraps.
- copper tape to bronze underwater propeller strut => I changed that and now run it to dynaplate only 3 ft from atu

I advise you to use "the best of several worlds" and at least add one extra ground system to the dynaplat eg the S/S rubrail as you suggest. Make sure you make good mechanical contact and protect ot from moisture and corrosion.

jan
ON3ZTT

That sho
-

[Goudurix]

As for cleaning a dynaplate, periodic underwater scrubbing with a brush is what I do .Spraying sodium hypochloride on it, let it soak for 1/2 an hour, then rinse abundantly, at haulout to clean in-depth should do.

I think even when partially clogged it will still offer better contact surface than other underwater bronzes such as seacocks.

Jan
ON3ZTT

[El Pinguino]

Is free... is good...

I have one as part of my ground... two s/s FW tanks comprise the rest of it... works good.

[AfterHoursNLCT]

Gordon West has this to say about marine radio grounding techniques:

http://www.kp44.org/ftp/SeawaterGrou...GordonWest.pdf

Hope this helps....LL

[jcapo]

I have one but its covered with growth in a few weeks after a bottom job.

I also have 250 gallons of tank area in my ground system connected with 4" .032 copper from GEORGIA COPPER - Copper ground strap Good prices there.

[boatbod]

My previous boat had a dynaplate connected to the tuner with #8 awg wire. These days I know that's "all wrong" as far as rf design, but it did put out a particularly powerful signal up and down the US East Coast and I would assist as a net control relay on numerous occasions.

My current boat has inlaid copper strap, but it's not worth anything as far as signal goes. Can't get out on air no matter what I do. One of these days I'll rip it apart and replace with a dynaplate and/or Kiss counterpoise.

[Paul Elliott]

The Dyna Plate is a good ground. The sintering does nothing much to improve the RF characteristics, but it's still as good as a plain solid plate, and that's pretty good. I agree with Goudurix: if you can do it, running more than one ground connection isn't a bad idea.

[a64pilot]

Originally Posted by AfterHoursNLCT

Gordon West has this to say about marine radio grounding techniques:

http://www.kp44.org/ftp/SeawaterGrou...GordonWest.pdf

Hope this helps....LL

It does, thanks.
Now my question is how wide and thick a copper strip? I assume thickness only gives physical strength, but how wide? 2", 3", 4", 6" ?
Is there a point of diminishing returns?

[Frankly]

2" is probably fine (3" max), the RF travels on the surface (front and back) . I have found that some of the thin copper foil sold by the Marine Stores will just simply rot in a salt atmosphere (in time), so if you can find something a little heaver then it will last. Might try Storm Copper up in Tennessee. Connect it to all 4 bolts if possible and have nuts/washers sealed against the hull so you can play with the foil connections and not worry about starting leaks. Tinning the area around the foil connections is also a good idea and run the foil all the way to the ground connection on the tuner if possible (although there is usually a short wire inside).

[ka4wja]

A64,
First off....sorry I've been away from CF for a couple weeks....been taking care of family matters....
And, by now you've probably got the thing installed...

Originally Posted by a64pilot

What is you opinion on them?
I have a change to get one, installation is a little daunting, but are they worth it, are they the best way?

But, back to your question....


Nothing wrong with Dynaplates....I use two of the "Super" sized ones myself on my current boat....(and have used them for years on other boats as well)
They work great!
But...


But (as Paul rightly points out), don't buy into the adage that they work great because of the "sintered-bronze"....as a solid bronze plate of the same size would work just as well!!
{Years ago, I actually checked and found the 18" x 6" x 1/2" Guest Dynaplate, at $350 then, was only about $20 more than havng a 18" x 6" x 1/2" piece of solid bronze, cut / machined (I don't have a machine shop)...
Not sure what the prices are now, but if you have Marelon thru-hulls (like I do), then the choice is either making your own or buying a Dynaplate...}

Now, since you got it for free (or close to free?), go for it!
Mount it and use it, and use some 0.012" thick (or even 0.022" thick), 2" to 3" wide copper strapping to connect it to your remote tuner (dab a little Penetrox-A conductive grease on the strap-to-bolt connection), and you'll be good for decades!



Here are a couple pics of my current boat's Dynaplates...



Yes, I have two of the "Super" sized Dynaplates...
And, I used 6" wide copper strapping to run the 8' to my Dynaplates, and some 3" wide strapping run 10' farther forward to the keel bolts....but, I'm a radio nut, you know!






Now, for those who have bronze thru-hulls (mine are Marelon), and have one or two within 6' to 8' of your remote tuner, just run some 3" wide copper strap to the bronze thru-hulls, attach it securely (and I recommend using Penetrox-A conductive grease to maintain a low-resistance, fairly water-proof connection), and you're done!!! (no need for a Dynaplate)









As for copper strapping....it's all about having a low-impedance connection to the sea water (that is your actual RF ground / antenna ground, here)....and that's all about length....so the shorter the run is, the smaller the strap can be....the longer the run, the wider the strap should be....
2" is fine for most applications in <40' boats....3" is the "standard"....(I use 6"!)
FYI, 1" wide strap has less RF inductance than 0000ga wire....so, you see what we are trying to accomplish with the strapping (btw, I have posted the formulas before, as well as the comparisons....might take me a while to find 'em, but if you look at the SSCA site, they are there somewhere!)

Originally Posted by a64pilot

It does, thanks.
Now my question is how wide and thick a copper strip? I assume thickness only gives physical strength, but how wide? 2", 3", 4", 6" ?
Is there a point of diminishing returns?

Try the boys at Georgia Copper, they great guys to do business with!
http://gacopper.com/012-CopperStrap.html
http://gacopper.com/022-CopperStrap.html



Hope this helps!


Fair winds.


John

[a64pilot]

I have ordered 25' of .032", 2" wide copper strip from Ga copper, supposedly pure, soft copper in annealed condition.
I figure after installation I will conformal coat it to help prevent corrosion.
Just have to install everything else now, I plan on using my Starboard back stay for the antenna

[ka4wja]

Wow, .032" thick...well, a bit thicker than I like to work with on boats (tight spaces, you know)....but it all depends on where/how you can run the strap...

Good luck and don't sweat the "counterpoise", it's not critical...learning about radiowave propagation will go a lot further in optimal results of any HF radio set-up, than "how much copper", etc.!!

Fair winds...

John

[a64pilot]

Yeah I agonized a little bit over 22 or 32 thou., but decided if it's going to corrode, better to start thick. The run ought to be easy. That is the way most of my projects start out, ought to be easy, then I find all that structure I forgot about, that is in the way