On Saturday, March 09, 2019
10:31:41 PM you wrote:
HI Stephan,
the proposed experiment
with two 10 meters antennas is interesting but...
...is this an
electromagnetic (Maxwell) transmission or an electrostatic (Coulomb)
transmission?
73 de Claudio IK2PII
> Hi Jim,
>
> I hope you don't mind
that i'd like to share the email with the
> reflector, because
i've a thought that might be interesting.
>
> In my view, the Loomis
experiment it is rather the detection of a
> changing current
(charge per time) on the RX site. The changing current
> is coming from a
change in the static electric field, caused by the
> shortcutted 'TX'
antenna. Something like a current divider.
>
> In 2010/2011 i've done
VLF transmissions on my own, using a 300m
> vertical kite antenna
(having a special licence for that altitude). The
> antenna capacity was
about 1.5 nF. During an experiment in the summer
> time there was a short
moment when the vertical wire was floating. It
> quickly charged up to
some kV, which was quite noticable when i catched
> and touched the wire
then!! Since that time i carefully kept the wire
> grounded during such
experiments.
> So, it means that the
wire charged up, so there must be some continuous
> charge flowing onto
the wire and, if the wire would be grounded
> permanently, you could
probably measure a more or less stable current, i
> guess it would be some
100 uA.
> Now imagine someone
else would rise a grounded kite in a few meters
> distance. This would
certainly affect the current flowing in my kite
> wire. The farer both
'antennas', the lower expressed the effect will be
> and the higher the
antennas, the stronger it will be expressed.
>
> I think the effect
would be much better expressed by measuring the
> voltage across a 1
MOhm resistor instead, which could be done by using a
> scope and some
overvoltage protection!
> Actually an
interesting question: In the summer time, which DC voltage
> could be measured over
a 1 MOhm resistor when connecting to a large E
> field antenna and
ground?
> And, a next step: If i
let my antenna charge up (floating) and then
> discharge it in exact
time intervals, say each second, then i should see
> something at 1 Hz on a
suitable receiver. This would already come close
> to the experiment i'v
done. I'm just replacing the 'natural charge
> source' by a high
voltage power supply and modulate that voltage (with a
> sine wave, not
rectangular).
>
> So, to answer your
question, i think that Loomis experiment was not
> dedicated ELF, it was
rather a broad-band spectrum that was radiated,
> since the charged
antenna was discharged immediately. For a real ELF
> transmission i would
say that the carrier frequency has to be at ELF,
> not the modulating
frequency. OK here you might say the carrier
> frequency is 0 and it
is AM modulated...
>
> Try to repeat the
experiment! Use smaller antennas and shorter
> distances. Could be
interesting :-) Rise two 10m high wires in 10m
> distance in an open
field. Connect one of them to a scope (1 MOhm input
> resistance), protect
the input with a glow lamp. Keep the other wire
> floating. Select 1
second/div. If there is a thunderstorm coming and you
> can see a rising DC
level on the scope, then do a shortcircuit on the
> other wire. I bet you
will see the voltage dropping on the scope.
>
> 73, Stefan
>
> Am 09.03.2019 19:10,
schrieb James Hollander:
> > Hi Jacek and
Stefan, I’d like to suggest that while I can’t say for
> > sure there
weren't ELF frequencies received in the Loomis experiment
> > of 1866, I’m
hesitant to reach the conclusion ELF was used by
> > Loomis because of
the following questions.
> > 1) If the
transient current that flowed when Loomis’ transmitter
> > circuit was
closed probably lasted only a few milliseconds, wouldn’t
> > the modulation
frequency content *exceed at least the upper ELF
> > boundary 30Hz* as
impressed on the “carrier”?
> > 2) With a 600’
long TX antenna and only a galvanometer fed by similar
> > height RX
antenna, wouldn’t any radio waves that might have been
> > received be
shorter than 10x the wavelength for which a 600’ TX
> > antenna is a
quarter wavelength? 10x(600’x4)=24000’ or about 8km. If
> > the wavelength is
less than about 8km, wouldn’t the “carrier”
> > frequency content
exceed about *37 KHz*?
> > 3) Nevertheless,
one might say, if galvanometer deflected temporarily
> > in Loomis’
system, it must have detected some near-DC content unless
> > some nonlinear
element were in the receiving circuit. If I Fourier
> > Transform a
damped DC transient, what is the frequency content?
> > 4) If there were
DC transfer, wouldn't we say it's in the nature of a
> > current charging
an atmosphere-ground capacitance through the ground
> > resistance, not
radio in near field ELF? Or should we say the meaning
> > of “frequency” in
this case becomes so fuzzy that Loomis both did and
> > didn’t use ELF?
> > 5) If indeed
Loomis communicated any ELF, can’t one still radically
> > distinguish the
12.67 Hz experiment at DK7FC as involving a very
> > narrow band
continuous wave with 227 hours integration of this
> > continuous wave
to detect it and make it separable from other waves
> > that could be
generated in the ELF band?
> > I’m new to the
subject of ELF, and would appreciate any words of
> > wisdom you’d like
to give.
> > Vy 73, Jim
Hollander W5EST
> > -----Original
Message-----
> > From: Jacek
Lipkowski <[email protected]>
> > To: rsgb_lf_group
<[email protected]>
> > Sent: Sat, Mar 9,
2019 4:28 am
> > Subject: Re: LF:
RE: RE: Almost touching the ground... | 12.47 Hz
> >
> > Actually a
similar experiment to Stefan's has been done already, and at
> > much lower
frequencies (almost 0Hz :):
> >
> >
http://aerohistory.org/Wireless/loomis.html
> >
> > In this case the
power supply is from the cloud electric field and
> > probably had
quite a few more kV than Stefan's.
> >
> > Please note the
DX distance.
> >
> > VY 73
> >
> > Jacek / SQ5BPF
> >
> >
> > *From: DK7FC
<[email protected]*> To: rsgb_lf_group
> >
<[email protected]>
> > Sent: Tue, Mar 5,
2019 12:50 pm Subject: ELF: Almost touching the
> > ground... | 12.47
Hz
> > Hi ELF friends,
During the last 2 weeks i've done another experiment
> > on ELF, this time
> > on 12.47 Hz, the
24 Mm band (wavelength 24057 km). Again i've crossed
> > the local
distance of 3.5 km. That's the lowest frequency i've ever
> > been and it feels
like i can see the ground already :-) The dimensions
> > of everything
down there are extreme. I've integrated 227 hours of a
> > carrier
transmission into one spectrum peak, it is shown in the
> > attachment in
1.25 uHz. This carrier could have transferred an EbNaut
> > message of nearly
100 characters.
> >
> > The ERP was 50
attowatt or -163 dBW and the antenna current was 170 uA
> > only, despite
about 5 kV antenna voltage.
> >
> > I'm now trying to
put a step below 10 Hz but the RX antenna becomes
> > less efficient
with each Hz. 73, Stefan
----
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