On 4/16/2012 5:16 AM, Ian Jackson wrote:


To push and pull the current in and out of the capacitor, it was
necessary to have a good, solid, zero-potential reference point, and the
best one available was ground/earth (or, at sea, the hull of the ship).
So, for the types of antennas being experimented with (and used) at the
time, Marconi was absolutely correct.

Yep.. I think the frustration tends to be difficulty in understanding
that it's just one type of system, and others that do not require any
ground connection do exist.
Which means you would have to classify his statement as incorrect in
the overall larger picture. I believe most have already stated that
while some antennas do require such a connection, any "complete"
antenna does not require one.

The vast majority of my antennas do not require any ground connection
for proper operation.
Fer instance, I'm sitting out in the woods up at my recreational living
center.. I have dipoles strung up in the trees which I leave there,
and I roll the rg-58 coax up and hang it on a tree branch when I leave.
Not a ground wire, or ground connection in sight.. And works perfectly
well. Of course, you can't really see the wires here, but "S" can trust
me, there is no ground connection. The radio is sitting on that stone
bench, and the only connections are 12v to my car battery, and rg-58
coax feeding the dipoles. "I have 80 and 40 meter dipoles fed parallel
with a single coax, and can slap a tuner on it, if I want to use some
other band. " I have videos of this radio session using almost every
band from 80m to 10m.. I went through each one seeing if they were
active. They all were, up through 10m, on that day. If one wants to
hear another band, just change the "80" in the url to "40", 20", "17",
etc.. I think they should be on the server.. I think I missed 12m
though for some reason.. Maybe no one was talking when I tuned it..
But it was open to somewhere, as I recorded Rarotonga Islands on 10m.
http://home.comcast.net/~disk200/80.wmv

Also, it wouldn't have taken them long to appreciate the benefits of
bringing the antenna system to resonance on the frequency the operators
wanted (rather than it simply being an act-of-God and hope-for-the-best
affair).

But note that with Marconi's famous crossing the Atlantic experiment, I
believe there is no documentation of exactly what frequency was used.
Instead of it being something extremely low (which is what they
expected), it is now thought that the signal which travelled 3000 miles
would have been one of the many harmonic resonances of the antenna, as
this would have been excited by the extremely wide band of frequencies
created by the spark transmitter. Knowing now what frequencies cross the
Atlantic in daylight, the signal might have been as high as 10 or 15MHz
(frequencies which Marconi only dreamt about using!).

It wouldn't surprise me too much. Heck, I've been faked out more
than once when using cheap receivers, and picking up something that
was actually not on the frequency that I thought it was. :|