charles_reed
Active member
Sorry we're at cross-purposes here.
There are 2 different types of earth being referred to here and confused together.
The one is the standard electrical earth or, more properly -ve.
The other is the RF earth.
On a standard land-based radio system the RF earth is just that - a spike driven into the earth.
It's more difficult in boats, especially in fresh water - but theoretically you can get a similar effect by having a large conducting area either in the water or below the waterline.
Many marine radio hams chuck a large weight overboard to act as the earth, others reckon a plate bonded into/outside/inside the hull works just as well.
As far as I know there's been no quantitative comparisons done on the relative merits of each method.
However there appears to be no doubt in all the experts minds that all radio devices benefit by having a return to an RF earth.
That's why you always have a wire from the chassis of a car radio to the engine or main pan pressing.
Even your vhf will work quite a lot better if you attach the outer core (shielding) of the co-axial aerial to the chassis and to an RF earth.
There are 2 different types of earth being referred to here and confused together.
The one is the standard electrical earth or, more properly -ve.
The other is the RF earth.
On a standard land-based radio system the RF earth is just that - a spike driven into the earth.
It's more difficult in boats, especially in fresh water - but theoretically you can get a similar effect by having a large conducting area either in the water or below the waterline.
Many marine radio hams chuck a large weight overboard to act as the earth, others reckon a plate bonded into/outside/inside the hull works just as well.
As far as I know there's been no quantitative comparisons done on the relative merits of each method.
However there appears to be no doubt in all the experts minds that all radio devices benefit by having a return to an RF earth.
That's why you always have a wire from the chassis of a car radio to the engine or main pan pressing.
Even your vhf will work quite a lot better if you attach the outer core (shielding) of the co-axial aerial to the chassis and to an RF earth.