Hollyweirdos said:
Thanks for the info. The tip idea came from that study done by the university in Florida. There is a link on this thread. I thought it was supposed to have this " air terminal". The boat will not be in a marina. Do you think it will be wiser to remove?
Also have a question about bonding down below. Do you know if it is a good idea to connect the metal items inside the boat? That study implied that bonding was needed. Thanks for your time. Kevin.
I can only speak to what is common in land based communications towers and facilities, but one school of thought here is to have a lightning rod attached to the top of the tower and ensure that it is the highest point on the tower. I thought it was some fancy kind of rod, but turned out it's just a standard copper clad steel ground rod just like the one's at Home Depot. Rarely do we have antennas higher that that rod. I really don't have any specific observations on how effective it is.
In the equipment buildings at the tower sites, it is vitally important that every "significant" metal object be grounded. This includes metal doors and frames, electrical conduit, air conditioner vents, cable racks, light fixtures, etc. The purpose is, in the event of a surge, to have all metallic objects at the same electrical potential. In an ideal situation, you would bond everything onboard your boat on a similar manner. This would include bonding the mast to the shrouds, lifelines to each stanchion, and than bonding all to a single ground point. By bonding, I'm referring to attaching a heavy wire, such as #2 to the mast in a manner that makes an excellent electrical connection and then to each shroud. In the buildings, we put jumpers like that across each mechanical joint where two electrical conduits are attached end to end or from the conduit to the metal outlet box.
Ideally, that would be the best thing to do, but without a good single point ground, like a metal keel, it could be over kill to ground every major metallic object below the point where you actually make your earth connection. For example, on a water ballast boat, with wires at the base of the mast and routed over the side. Major surge energy will not readily flow upwards and any surge protection ideally, should be routed in a downward fashion. So if the surge is below the mast, it isn't going to be easily redirected upwards to your absorber at the mast base.
One method common in radio installations is to run what is commonly called a halo ground around the radio room with several attachments to the earth ground around the room, typically in the corners. All of the significant metal onthe building is attached to that ring. The theory is that the halo will create a Faraday Shield which would help protect from induced voltage caused by the EMP of a nearby strike. In a metal keel boat, this might be effective protection for sensitive electronics.
