Scott Downey wrote in message
...
There is a large stainless metal ground plate with molded in tubes (
increased surface area) attached to the keel.
About 4 feet by 2 feet. I was told years ago these plates may have been
used
for AM ground plates??? when using an AM transmitter or perhaps for
lightening protection. The boat was built in 1970. All the electronics
are
grounded and this is also included in the ground.


Probably would work O.K. for the 2-3 Mhz HF marine band and a mast supported
antenna wire, but you'll need a "local" groundplane for the 27Mhz antenna to
attach the coax shield to, as was previously questioned.