Re: lake ground?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Subject: Re: lake ground?


 > Original poster: "Ed Phillips by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>
 >  > Original poster: "Jerry Chamkis by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <jchamkis-at-bga-dot-com>
 >  >
 >  > there was an AM radio station on Catalina Island that had wire mesh in
the
 >  > (salt) water for their ground.  They had a -famously- strong signal.
Might
 >  > be irrelevant though- sea water is presumably orders of magnitude more
 >  > conductive than fresh...
 > Since the beginning of "wireless" commercial stations, both radio and
 > communication, have always attempted to use salt water marshes for their
 > antenna siting.  I suspect that even "lake water" is conductive enough
 > to help and that anything on the bottom would have enough local mineral
 > contaminiation to help quite a bit.
 >

Hence the popularity of the Salton Sea as a 160m contest site..

But anyway, the high conductivity ground (salt marsh on the top of a hill
type sites) is mostly for far field propagation... I don't know that it
would make all that much difference for a TC.. most of the field in a TC is
the E field in the capacitor formed by the topload and the ground.  It's the
ground conductivity in the adjacent area ( radius approximately equal to
topload height) of the TC that's important from that standpoint.  A 10 foot
square of chicken wire is probably the ne plus ultra.