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Old May 23rd 06, 07:35 PM posted to rec.radio.amateur.antenna
chuck
 
Posts: n/a
Default Yacht Rf ground and radials

Richard Clark wrote:
On Tue, 23 May 2006 23:44:50 +1000, Will
wrote:
They suggest running copper foil to a Dynaplate and use sea water as
the ground. How can this work when the Dynaplate is below sea water?


Hi Will,

Below is better than above, to say the least. How much below is
immaterial.

Is sea water equal to copper wire radials as a RF ground system?


Skip the pursuit of the Holy Grail in radials, this may lead you to
start carrying buckets of dirt which screws up buoyancy.

Why do i have to use copper foil when most other people suggest using
ordinary copper wire?


Probably more surface area.

All ideas and comments appreciated.


How good (or poor) sea water is for matching and loss, is seeing the
glass 3/4's empty. How good sea water is for propagation is seeing
the pitcher nearby and filling your glass several times.

73's
Richard Clark, KB7QHC


A few additional questions along these lines for the group (with some
paraphrasing):

1. What is the skin depth in salt water at 14 MHz? How would this affect
a ground plate at four feet below the surface?

2. What would the ohmic losses be over a one square foot by 33 foot path
through salt water?

3. How well would the ground plate work on fresh water bodies, such as
much of the Chesapeake, the Great Lakes, and various rivers and
tributaries often used by cruisers? How would it compare with radials
over fresh water?

4. Can anyone cite a published and reproducible study in which the RF
losses through salt water were measured and compared with losses through
one or more copper wire "radials" on or below deck of a typical cruising
vessel? Or is there a published theoretical analysis of this comparison?
Looking for more than the casual, anecdotal stuff.

5. Will a four foot length of wire dropped into sal****er provide a
"good" RF "ground" and on what is the answer based?

I need enlightenment!

Thanks, and 73,

Chuck
NT3G