Single Side Band-ground plane

[Roger]

I have a 1996, 39 convertable and would like to add a single side band radio, however I can't seem to locate the ground plane stud that is usually installed by hatteras at the factory under the helm or brow. i contacted hatteras and they are not certain the boat has a ground plane, not a comforting answer. Therefore does anyone own a 39 convertible with a SSB and can provide me with information on loaction of "ground plane stud" etc.
Or how can I determine if the ground plane foil exists in the flybridge deck? Also what options do I have to provide a ground plane if it doesn't exist, or proper grounding method. I understand you can use regular round wire because it transmits RF, need foil etc. I would like to avoid "frying" my electronics on board with stray RF wattage looking for a path to ground, and not traveling thru my electrical system, electronics or stereo etc.

[Trojan]

I don't think you will find a ground plane for SSB incorporated in the boat.What is used is the ground PLATE attached to the outside of the hull.It's about 1/2in X 4in. X 8in.bronze and has a stud coming through the hull in the bilge.It is the standard grounding plate for SSB.There is not a ground plane per-say for SSB.It would be to large.Though there could be for VHF FM.The counter poise (ground plane)for HF is the water.You need some type of an antenna tuner for SSB.The Icom AT-140 is a good auto tuner for marine .Then all you need is a tall whip antenna.You could also use a screwdriver antenna.This is what I use.Or you can use a manual hand tuner.Large ships use Dipole antennas,they have the space.40 meters is about 60 feet long.The antennas for SSB can be quite large if you remember the old Am 160 meter ship to shore.SSB on small boats is a Little tricky it depends on the frequency or frequencies you want to operate.I operate 160 Meter through to 10 Meters.Bill

[Roger]

Bill-if I run a copper foil from antenna tuner located under port side of helm,then down thru wire run containing all cables, wires, hoses etc leading to engine room, and then connect that foil to the grounding plate stud, the question is will it be safe to assume it will not radiate any energy into all those wires inside the wire run. There is not other way to get from flybridge to engine room except thru this wire run. thanks Roger

[Trojan]

Roger I would Try an use a piece of RG8U coax from the tuner to the SSB plate.Attach one end of the center wire to the tuner counterpoise terminal.The other end to the SSB ground plate in the bilge.The outer braid should go to the general ground.Expose about 2in of inner cable.You may need to ground both ends of the shield or remove the ground at one or the other end.This is a trial an error situation.You will need some type of coil and whip for the antenna.What frequency do you plan to transmit on and how much power will you run.I can run 8o o watts on my old boat,800 watts in my car and 2500 Watts at home.With the 7.5 KW generator on the new boat I suppose I could run the 2500 watts on the new boat.Make sure you run a separate ground wire (12GA)from the tuner and transceiver to the common ground.NEVER TUNE UP WITH A HIGH SWR!!!! Pre-tune,pre-set with a minimum of power or you will put stray RF. in the cable run.Bill

[Boater260]

Roger - I have two SSBs on my 39: one in the electronics box overhead in the bridge and one on the port wall in the salon - where your electronics panel is. The next time I'm at the boat I'll open the back of the overhead box and see where the ground goes. Not knowing what a ground plane is, I assume you mean where the SSB is grounded. (What do I know, I'm only an attorney.) If not, let me know what I should be looking for and I'll look for you. I also owe you pictures of the Kim Hotstart engine heaters I had Detroit Diesel install for me. I didn't forget you, just haven't been on the boat since November. Hope all is well with your new business. Barry

[Nonchalant1]

Hatteras does frequently put an "RF antenna ground" for VHF and other radios in their boats. It's put there so you don't have to run multiple wires. In the 53MY it's in the forward flybridge storage area on the floorboard. It's a threaded stud that sticks out of the fiberglass and all antennas can be grounded there. It'll be located somewhere on the cabin roof where the likely spots are for attaching RF antennas and their wiring.

Doug Shuman

[captddis]

I can't speak for the 39, but in the later years Hatteras stopped putting the ground screen in the smaller boats. I have installed a number of SSB radios. I have always used the foil down to a dynaplate then also tied into the bonding system. Have not had any Rf problems with the foil. But did have a boat where the coax from radio to the tuner went down a tube with a lot of other wires. The tachs would bounce when transmitting. When in doubt. Ground, ground, ground.

[Trojan]

A 1/4 wave ground plane for vhf is only about 18in. dia..Easy to put in the bridge.HF ground planes are to big to put on a boat.You use the water for the ground plane.You guys must not remember the old 160 meter AM. ship to shores.The copper strapping is not a good RF.counterpoise.It is a good ground up from the real ground for vhf and above.If your meters are moving you have a high standing wave.All of your signal is not going out the antenna.It is not properly tuned to the transmit frequency.Its backed-up signal RF.staying in the boat.If it is strong enough you will burn the transmit section out of your transceiver.Newer transceivers will lower the power out without you knowing it to prevent ruining the transceiver.Most of the fiberglass VHF antennas are 5/8 wave antennas and don't require a ground plane. Bill