Hi Jacek, DC,

Yes yes, i already see a new project for summer :-)

73, Stefan

Am 10.03.2019 09:58, schrieb Jacek Lipkowski:

I haven't tried this with 300m kites, but even ordinary low-band dipoles can charge quite quickly if they are high enough, so 100uA seems to be a good approximation. This is already comparable with the 170uA you're getting at 12.71Hz now (and which will be lower at lower frequencies).

The only problem is the switch, but a high voltage vacuum relay (or a few in series with a piece of fiberoptic for controlling each of them) should be sufficient upto a few Hz.

Also note that the more charge in the atmosphere, the more ERP you get. But it also gets more dangerous. No risk no fun on the "loomis band" :)

VY 73

Jacek / SQ5BPF



On Sat, 9 Mar 2019, DK7FC wrote:

Date: Sat, 09 Mar 2019 22:31:41 +0100
From: DK7FC <[email protected]>
Reply-To: [email protected]
To: "[email protected]" <[email protected]>
Subject: LF: Re: Re Loomis? & ... 12.47 Hz

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