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Old 05-05-2019, 11:14   #1
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SSB DC Ground Connection

So recently passed my General Ham License exam and wanting to try out a little HF communication from my boat attempted to reach the Cruisers Net 14.300 Mghz with no luck. I should mention that vessel is on the hard with a KISS as the radios counterpoise, pushing 100 watts from an old SEA 222, DC gound is to small Dynaplate. Back before obtaining the proper license I made contact from NY to Net Control in Chippawa Falls with the radio DC ground still connected to the Dyanaplate. Currently ground has been diconnected from Dyanaplate would that potentially have anything to do with not getting out a strong signal?
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Old 05-05-2019, 14:08   #2
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Re: SSB DC Ground Connection

What antenna are you using?
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Old 05-05-2019, 14:35   #3
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Re: SSB DC Ground Connection

To answer your question directly, no, it shouldn't effect your signal going out.

I take it that you can hear the Net well so you might want to try and see if there is a member of the net that you can connect with and you can note the direction from your location. Time of day, type of antenna, connections to antenna and tuner other masts, etc, will have much more effect on your signal.
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Old 05-05-2019, 15:16   #4
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Re: SSB DC Ground Connection

In addition to the KISS ground system being snake oil, with the boat out of the water you have a poor counterpoise. This is not your DC ground as the title suggests. This is an RF ground. Think of it as the other half of a dipole antenna. Right now we are at the bottom of the sunspot cycle and afternoon propagation on 20 meters is terrible.

BTW your SEA 222 puts out 150 watts if it is working properly. It is a PITA to use one on the ham bands. I have one next to my Kenwood TS-570DG which is also pretty old now.
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Old 05-05-2019, 15:28   #5
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Re: SSB DC Ground Connection

If you on the hard, Take about 15ft of wire, size doesnt matter, Connect it to the antenna ground and throw it overboard. That will give you some counterpoise.
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Old 05-05-2019, 15:51   #6
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Re: SSB DC Ground Connection

Conventional wisdom says to be an effective, you need multiple ground radials as a counterpoise. The KISS serves as a single radial. Although it has multiple lengths, it is still essentially a single radial. Out of the water and absent an effective counterpoise, not many people are going to hear you, particularly during the sunspot minimum we currently ‘enjoy’.

The only reason you may be hearing other stations is because they have an effective antenna.
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Old 05-05-2019, 16:42   #7
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Re: SSB DC Ground Connection

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Originally Posted by ohgary View Post
If you on the hard, Take about 15ft of wire, size doesnt matter, Connect it to the antenna ground and throw it overboard. That will give you some counterpoise.


I believe you could also connect it to the life lines and or rub rail.
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Old 05-05-2019, 17:43   #8
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Re: SSB DC Ground Connection

Well, if it is of any comfort, I have not been hearing MMSN very well. The conditions are not too ripe, at least for me in the SoCal region. So with that...

I have a homemade KISS with a 106.5' long wire. I get out just fine and I am on the hard, meaning... my qth. So you do not need your dynaplate right now. It is doing no good. And it is for RF ground only, never DC ground. You will end up with galvanic corrosion.

The question of what antenna needs to be answered. You also have the option of building a dipole for your "on the hard" comms. Run the center conductor side to the top of the mast, the shield side to the toe rail. Make sure you cut it for the correct frequency.

If you have a time you want to call on MMSN I can give a listen here. But again, band conditions are not that great right now. I can't even link to a WINMOR station in TX on 20M, or my favorite 40M stations in the San Francisco area.

Tell us your setup and when you would like to try to get on MMSN.
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Old 06-05-2019, 10:31   #9
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Re: SSB DC Ground Connection

I can't speak for what will work better with your boat and setup, but when I swapped out my backstay and went with a GAM antenna, I also swapped to a kiss counterpoise. After running it for a season, I was not impressed with my signal quality and started optimizing. I found when I went back to grounding my tuner and radio to the groundplane/dynaplate, my transmission quality was significantly better with no other changes.
Your mileage will vary, but I think it's swapping back to your dynaplate and see if it improves.

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Old 06-05-2019, 10:35   #10
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Re: SSB DC Ground Connection

Quote:
Originally Posted by cburger View Post
So recently passed my General Ham License exam and wanting to try out a little HF communication from my boat attempted to reach the Cruisers Net 14.300 Mghz with no luck. I should mention that vessel is on the hard with a KISS as the radios counterpoise, pushing 100 watts from an old SEA 222, DC gound is to small Dynaplate. Back before obtaining the proper license I made contact from NY to Net Control in Chippawa Falls with the radio DC ground still connected to the Dyanaplate. Currently ground has been diconnected from Dyanaplate would that potentially have anything to do with not getting out a strong signal?
I'm not a wire-head.

I use a SEA 2250 with a KISS and had excellent results on my roundtrip to Hawaii. However, in preparation for the trip I tested the equipment a number of times locally while anchored in Puget Sound and never got transmission success that I was happy with. In talking to the KISS manufacturer he kept telling me that I would see a difference offshore and he was correct.

I will add that in preparation for the voyage I took my unit (all of it; control head, transceiver, antenna tuner, mic) to the company in Mountlake Terrace, WA for a tune-up. Doug Hutchins did a great job and the cost was very reasonable...I saved a bunch over buying a new ICOM unit.

~ ~ _/) ~ ~ MJH
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Old 06-05-2019, 10:41   #11
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Re: SSB DC Ground Connection

A boat on the hard has no counterpoise. I would wait until the boat is back in the water and try again.

Once in the water, I would fo back to what worked which was the dynaplate connected to the tuner ground. Make that a wide (2-3 inch) copper strip.

There is an old radio saying; if it ainít broke donít fix it.
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Old 06-05-2019, 10:52   #12
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Re: SSB DC Ground Connection

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Originally Posted by DeepFrz View Post
To answer your question directly, no, it shouldn't effect your signal going out.

I take it that you can hear the Net well so you might want to try and see if there is a member of the net that you can connect with and you can note the direction from your location. Time of day, type of antenna, connections to antenna and tuner other masts, etc, will have much more effect on your signal.
Just to add to Deep's excellent post above: Personally, I'd ditch the dynaplate if you're in an area prone to lightning. For RF, you don't need DC continuity to "ground" and a counterpoise will capacitively-couple to the sea. A lightning hit to your boat will presently be routed to the dynaplate for dissipation, which can cause the water to boil. Since the surrounding water is incompressible, that expansive steam pressure has no place to go but into your hull - to which the dynaplate is rigidly attached. A demolition engineer would love this configuration - it's the best way to blast a hole in something - your hull in this case. It's like hitting a mine. If the plate is made of any material other than zinc, and if it does not have a DC decoupling capacitor in series, it will also contribute to galvanic corrosion of your prop and shaft, or at least rapid corrosion of the zincs on the shaft. Plus, the dynaplate is only a tiny fraction of a wavelength and will consequently contribute very little to RF performance. The plate seems useful only if you ignore the vast difference between DC and RF.

I trail 25 feet of stainless steel braid (more is better) off the stern that is terminated at my common ground point, both as an RF counterpoise/ground plane and for lightning dissipation. (Don't use copper - it'll dissolve in sea water.) You can buy the braid at American Grounding Systems. http://www.ags.bz/ The 1/2 inch width is adequate. It works great. Above 2 knots, it trails along right at the surface. You can add floats to keep it above the prop (I don't bother with that.) And the braid doesn't get fouled if you haul it back aboard after use.

Finally, with your current configuration, you will probably see some improvement once your boat is back in the water so it can utilize the water as an RF reflector.

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Old 06-05-2019, 13:43   #13
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Re: SSB DC Ground Connection

If there is a chain wire fience close conect your earth wire to it , It makes a grat counterpoise , Im Using that at the moment ,,, vk2loz
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Old 06-05-2019, 13:54   #14
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Re: SSB DC Ground Connection

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Originally Posted by Cpt Pat View Post
Just to add to Deep's excellent post above: Personally, I'd ditch the dynaplate if you're in an area prone to lightning. For RF, you don't need DC continuity to "ground" and a counterpoise will capacitively-couple to the sea. A lightning hit to your boat will presently be routed to the dynaplate for dissipation, which can cause the water to boil. Since the surrounding water is incompressible, that expansive steam pressure has no place to go but into your hull - to which the dynaplate is rigidly attached. A demolition engineer would love this configuration - it's the best way to blast a hole in something - your hull in this case. It's like hitting a mine. If the plate is made of any material other than zinc, and if it does not have a DC decoupling capacitor in series, it will also contribute to galvanic corrosion of your prop and shaft, or at least rapid corrosion of the zincs on the shaft. Plus, the dynaplate is only a tiny fraction of a wavelength and will consequently contribute very little to RF performance. The plate seems useful only if you ignore the vast difference between DC and RF.

I trail 25 feet of stainless steel braid (more is better) off the stern that is terminated at my common ground point, both as an RF counterpoise/ground plane and for lightning dissipation. (Don't use copper - it'll dissolve in sea water.) You can buy the braid at American Grounding Systems. http://www.ags.bz/ The 1/2 inch width is adequate. It works great. Above 2 knots, it trails along right at the surface. You can add floats to keep it above the prop (I don't bother with that.) And the braid doesn't get fouled if you haul it back aboard after use.

Finally, with your current configuration, you will probably see some improvement once your boat is back in the water so it can utilize the water as an RF reflector.

73
N8QH
So much interesting knowledge to be shared here. So if I understand what your saying here the bronze Dynaplate that is used to help minimize RF interference really doesn't work that well and can actually carry stray electrical back into vessel jump over to the DC ground wire, that in my vessels setup terminates at my vessels engine block and potentially induce corrosion on all the items connected to that common DC ground bus?
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Old 06-05-2019, 14:50   #15
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Re: SSB DC Ground Connection

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So much interesting knowledge to be shared here. So if I understand what your saying here the bronze Dynaplate that is used to help minimize RF interference really doesn't work that well and can actually carry stray electrical back into vessel jump over to the DC ground wire, that in my vessels setup terminates at my vessels engine block and potentially induce corrosion on all the items connected to that common DC ground bus?
"... used to help minimize RF interference..." Actually, it can accomplish the task of discharging the rare occurrence of static electrical charge build up on a non-conductive hull (wood/FRP) that would otherwise produce corona discharge ("St. Elmo's Fire") -- that when unmitigated will produce interference in your radios. But anything conductive placed in the water that is connected to your ship's common ground (your engine block, in your case) will do the same. Your prop and shaft connected to your engine should work just fine for discharging these minuscule currents. Lightning, on the other hand, should be discouraged from passing through your engine's main bearings. A hefty bypass strap from the engine block to the transmission case will do that job.

"... induce corrosion on all the items connected to that common DC ground bus?" No, only less-noble metals that are in the water. Galvanic corrosion requires two electrically connected but dissimilar metals sharing a common electrolyte (seawater). The effect diminishes by the square of the distance between the two objects. If the dynaplate, your prop, and prop shaft are all bronze, then you're OK.

But the topic is radio frequency (RF) transmission/reception. From an RF standpoint, the dynaplate is just a small piece of metal that happens to be immersed in water. Nothing more. It's about as effective at anything to do with RF transmission as wearing a copper bracelet to prevent arthritis. Or a rabbit's foot in your pocket. It's just a magic talisman. But it is effective at dissipating lightning explosively right next to your hull, and encouraging corrosion of any less-noble metal nearby in the water to which it is has DC continuity.
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