Oznog

I have 100KV high tension lines over the rear of my very long plot, about 250 ft from my house. It's very dark back there.

Lemme get something out of the way. I KNOW that you cannot "steal" any significant amount of power by putting a pickup coil under high tension lines. The story about a farmer making a coil and powering his shed from "unbalanced" power lines is an urban legend. There are a bunch of these stories and they're all urban legends. Nothing you can do will drain more than the faint power than it normally radiates out.

BUT, a simple experiment shows that a fluorescent tube glows very faintly. Far more significant still, an LED glows faintly but still far more intensely and in a more noticeable fashion! The sheer novelty of this has me fascinated.

I took electromagnetics and antenna design YEARS ago. And I certainly don't recall 60Hz antennas being in the textbook. Is anybody more current on antenna design knowledge? 'cause I'm wondering what the most effective pickup would be. The tallest, I suppose, or do we need to have a high pickup then a shielded wire to make the greatest differential to ground? The lines are quite high up there, even a 10 ft pole isn't going to be a safety hazard. I could do a stick of bamboo tied to a fence pole, 10 ft's about the best you could hope for without guy wires. Wind and all.

I already figured out that we need two LEDs in parallel but opposite directions to properly exploit it, since each LED only uses the current in one direction and it's picking up AC. Now, how many LED pairs can be driven in series? I wanna see it bad...

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

RadioRon

Applying antenna concepts doesn't make any sense when your spacing away from the tx line is only 0.00014 wavelengths. You need to think like a transformer or capacitor designer. This is all near field coupling that you want to do so imagine the tx line is an inductor and you are going to put a secondary winding nearby to couple energy. What would that secondary look like? Similarly, why not couple electrically, instead of magnetically, using a capacitive plate?

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RadioRon

k7elp60

Well I'll bet if you did a large loop and the put a capacitor in parallel of a value that made it resonate at 60Hz you would have enough power do some interesting lighting. I have held fluorescent tubes and neon bulbs in a strong RF field and they both glowed pretty bright. I am not sure wether it is the electostatic or the magnetic field the caused them both to light up. The power of a resonate circuit is somewhat amazing as the circulating current can be awesome.

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The great thing about electronics is unlimited ways to do the job. The only limit is one\'s imagination. I generally think my way is best.
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RadioRon

Yes, a large loop is effectively a one-turn transformer secondary and you get strong magnetic field coupling. Resonating only makes it better as you point out.

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RadioRon

Oznog

Well, yes, it does beg the question, how well a plate would respond. I'll be trying that. But I think in the long run tinfoil on poles is going to make the neighbors think I'm in the tinfoil hat club.

Actually plates on a pole would be in danger of being taken down by wind, unless I can think this one out.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

Oznog

It does act like a constant current source. Curiously, I had 4 red LEDs in series and each still glows with the same intensity as the one. That's easy to test, look at the one LED at the base of the string when I'm touching the end of the string versus just that one. No brighter/darker.

A test lead causes a glow of only about 1/5th what I get when I hold onto the end of the lead. Clipping the lead onto an adjacent steel fence pole seems to have the same intensity as me holding it.

I brought my Fluke meter out there, I'm concerned about meter impedance but this is still 60Hz. Curiously, between 2 fence posts- which lit my LEDs equally well as holding onto it- measured nothing on the AC scale. Like 30mV. However, simply holding onto the end measures 60V!!! Wow, I could light up quite a few LEDs this way.

I tried to take a current measurement, but I put it on AC amps and used the 300mA input and got "0.03". The meter reads "0.05" just sitting on the kitchen table so that's not saying much. Say, I should know this, but there's a 300mA and a 10A input here but only one AC and one DC current selection on the dial. How does it "know" which one the desired signal is connected to? If I'm in the "300mA" scale, a reading of "0.03" is 30mA, not 0.03mA, right? Is it just using a single shunt and there's a 300mA fuse instead of the 10A fuse in case you feel the need to protect your circuit from you accidentally shorting it out with a 10A fuse on a current meter? I opened it up and the 10A trace runs past the 300mA trace without joining where I could still see it anyways.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

Hero999

I don't live near overhead cables and I can make a white LED glow by holding one lead in my hand and touching the other end on the radiator in my bedroom.

Just build a large inductor (like an AM loop antenna) and add the correct value of parallel capacitance to tune it to 60Hz. You might need to fine tune it by adding and removing smaller capacitors in parallel.

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Leftyretro

I agree, just construct a 60hz parallel tank circuit with as large a loop as can be useful. Now a 60 Hz half wave dipole wire antenna orientated parallel with the power line would sure to light up a LED or even a small neon bulb, but that would be a awful long antenna. A "shorten" dipole antenna using coil inductors and resonating caps would also work well I think.

Lefty

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Measurement changes behavior

Rolf

I think Radio Ron is correct. When Weller was trying to get his soldering gun on the market, they thought he was crazy for designing what was essentially a transformer with a half a turn secondary.
You have the high voltage primary, now you just have to make the secondary. I would string the longest wires I could with insulators in each end and one in the middle, parallel to HV wires. Then take some readings from the two wires in the center.
Be careful!