Re: 7.1Hz, how the heck did Tesla succeed?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

"Was this low value for loss associated with a leakage vertically across
the atmosphere (which would be constant whether there were any power
receivers in use?)  Or was it a percentage of lost energy in the waves
travelling between the transmitter and receiver?  Corum/Sutton seem to
be
talking about the loss between transmitter and receiver being incredibly
low."

	I'd have to look up his reference but he says that "only a few
horsepower" are needed to excite his antenna; I take that to mean loss.
If you perform a calculation as to the capacitance to earth of the
"conducting layer" he proposed to use (remember he says in his patents
that his proposed transmission medium was conducting layer to receiver
with earth return) you'll find that its so high that the reactive power
it would store at any reasonable operating frequency would be hundreds
of millions of "horsepower".  That's the stored energy; divide it by the
claiamed loss and you get a very, very high Q.  I've run through the
calculations and have them in a spreadsheet somewhere.  He neglects
corona loss, of course, which is a big factor for 60 Hz lines operating
above a few hundred kV.  Imagine what the corona would be from his
vertical conductor leading up to the "conducting layer".

	How do they explain those low losses considering the exceedingly low
conductivity of the ionosphere and the relatively high resistivity of
the earth?

"On the other hand, there's that Corum paper that say that low Q on the
transmission end is not such a big issue, since it's analogous to the
corona leakage and insulator conductivity on a continent-wide power
grid.
I wonder how many hundred KW (or MW?) are today being thrown away
worldwide because AC lines have a bit of corona and insulators have a
bit
of conductivity.  But this loss is set by system voltage, so it stays
the
same whether there are millions of washing machines connected to the
power
grid or not."

	They can't make the issue go away that easily, no matter what they
say.  Remember that Tesla's scheme of necessity requires incredibly high
circulating currents so that any loss at all destroys the efficiency.
As for commercial power lines, the operating voltage is a compromise
between corona loss at high voltages and lower currents and the
resistive loss at lower voltages and higher currents.  The HV DC lines
are an attempt to get a bit higher average voltage for the same corona
loss as a conventional AC system.

Ed