Continued from another topic:
Ermi ...
Continued from another topic:
Ermi ...
Thanks for your comments. I don't know about attaching a brass sheet under the hull ... The boat won't come out of the water until Spring. It effectively has two separate ground systems: 1) The boat's DC ground, which is bonded to the engine and power panel, and 2) Shore power ground which is just in the conduit to the breakers and AC outlets, and the marine charger, which isolates the two grounds.
Why would I need a ground other than the bonded DC negative ground system, which ends at a heavy copper braid to a through-hull to a large sacrificial zinc below waterline on the transom?
There are wires, including the negative ground of course, going from the power panel to nav lights, pumps, radios, stereo system, etc., basically from stem to stern. I don't think anything is in series.
I want the TX to work when the power goes out, which it usually does several times during winter storms, or when some idiot on the mainland crashes into a power pole.
I think I should mount the mast on a tripod on the cabin roof ... unless I can talk the port into letting me put it on a piling (heckuvvalot more stable when the ferries come in). I guess I could put a metal grid under it and attached to the boat's ground.
Because a number of boats have connected neutral grounds, the whole dock and the water close to it is pretty 'hot'. How might that affect my signal?
The sacrificial zinc in the water should make a good ground.
Sea water and Zinc? Hmmmmmmmm
"sacrificial"
🙂
Obviously you're not a boat owner ... but you may own a home.
Check the main ground rod(s) or grid for your house power. Chances are it has (or had and it's long gone ... happens a lot because people don't understand what happens) a chunk of zinc attached to it.
This is to prevent electrolysis from eating your ground connection, ultimately losing your ground bond to everything. IOW, any pipes, water heater cores, the list goes on and on, which are of different metal types cause electrolysis, which will eventually eat through even the heaviest ground connection wire. The zinc bleeds off the chemical reaction of electrolysis ... so that it eats the zinc instead of your ground wire. That's why it's called a sacrificial zinc.
These are more critical in marine grounding applications, because the saltwater, often combined with the problem of shore power neutral grounds coming in contact with negative DC ground systems making the water around them become hot, speeds up the reaction dramatically. My boat carries, let's see, four bolt-on flat round zincs on the aluminum trimtabs, at least two or three screw-shaft clamp on zincs (prevents the electrolysis of the bi-metal joint of the bronze prop and stainless steel shaft from eating the prop), a cylindrical one in a special bolt-in casting on the engine, and the big directly connected grounding one on the transom.
HTH ...