Re: SSTC As a transmitter.

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

Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

Jim: a small bit of information to add details. The probes are spaced to set
the range and the recieve probes are set at reght angles to the transmit
probes. I have sent 30Mhz vidio in this way with good results over a year of
constant use.
    Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Wed, 24 Jul 2002 20:11:18 -0600
> To: tesla-at-pupman-dot-com
> Subject: Re: SSTC As a transmitter.
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Wed, 24 Jul 2002 20:19:39 -0600
> 
> Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <jimlux-at-earthlink-dot-net>
> 
> 
> 
>>> During the '70s some radio amateurs were keen on what they called
>>> 'earth mode' communications, which basically involved pumping lots
>>> of LF power circa 20kHz into the ground, using two electrodes set
>>> into the ground quite some distance apart.  The receiver uses
>>> a similar pair of electrodes to pickup up the differential voltage
>>> due to the current field in the earth excited by the transmitter.
>>> As you can imagine the signal strength falls off very rapidly with
>>> range.
>> 
>> There are people still doing that.  I think 4 or 5 miles is considered a
>> good result.
> 
> This is basically a simple application of Ohm's law in a volume media.
> It's a common way of doing geophysical exploration: resistivity surveying.
> Nothing special going on here.. It's just basically a big resistive divider.
> 
>> 
>> My primary interest is in energy transmission for telecommunications
>> purposes.  Geophysical exploration also rates high on the list.
> 
> There is a fairly good elementary and intermediate literature on the web on
> the Geophysical exploration end of things (do a search for things like
> "Electrical Resistivity Surveying",Electromagnetic Prospecting", or
> "Electrical Resistance Tomography").  There's a web site at the Univ of
> Colorado (I think) School of Mines which has what is essentially an online
> textbook on all the various ways this stuff is done.
> 
> 
> 
>