A question for HAMs not about radio.

[Magus]

I know I'll sound like an idiot, but is it true that really big loop antennas somehow gather electricity from the air, as in enough to kill somebody and do you think it could be harnessed as to say fill a bank of batteries? I know the old crystal radios didn't even need batteries and used the strength of the signal as power, are these phenomena related? any ideas how to exploit it for use?

 

[ssonb]

To put it simply cause dats the only way my mind works.Any conductive wire has "potential" when exposed to electric or magnetic fields and will enhance the received or applied input.
The efficiency depends length, windings,shape,height,thickness and on and on,that's why ya see so many types of antenna styles being sold.
But yes but the input from the earths magnetic fields will make for some BIG loops unless you put them under a transmission power line right of way.

 

[Magus]

So if I had a 4 acre loop of unshielded antenna wire, it would potentially produce current? would it do so reliably and could I charge batteries with it?

 

[SheepDog]

How close are the AM transmission towers, radar facilities and power lines?

 

[Magus]

Half a mile to the nearest Hi tension line, miles to the nearest radio station.

 

[Neb]

Half a mile to the nearest Hi tension line, miles to the nearest radio station.

Good question but complicated math ?( that hated subject gets in the way)..
Ben

 

[kd4ulw]

Short answer: no, not enough to charge batteries.

 

[Magus]

So its not just pulling juice out of the air?

 

[montanabill]

Maybe it's rural legend or maybe not , I remember a story about a farmer who put in a serious amount of wire directly under a high voltage transmission line and was producing useable power. The power companies monitor things quite closely and they busted him.

 

[Magus]

Its no urban legend, I had a neighbor who got free cable off a bicycle wheel antenna and since he was 50' from the right of way, there was nothing they could do "back then."

But BOT, I was hoping the antenna was soaking up natural electricity.

 

[Supervisor42]

Its no urban legend, I had a neighbor who got free cable off a bicycle wheel antenna and since he was 50' from the right of way, there was nothing they could do "back then."

But BOT, I was hoping the antenna was soaking up natural electricity.

The answer is yes, there is RF power radiating everywhere. The problem is they are upping the frequency on everything making it less 'powerful'.
As a kid I had a crystal radio (no battery) and there was plenty of power for the earphone.

(which requires a very tiny amount of power)
I would hook the alligator clip to the ground wire from the TV antenna on the roof of the house, and in mid-Alabama be able to listen to WWL in New Orleans at night.
Good luck finding a high-power, low-frequency AM radio (RF) signal today.
So yes, that 30'-tall antenna captured power...... about equal to a battery the size of a pencil eraser.

 

[Magus]

No tickle charging a bank of batteries out of that I guess. I was hoping the loop could draw in natural electricity. Art Bell spoke of having to have a special ground to keep his from knocking him on his butt!

 

[kd4ulw]

10 minute video about Nikola Tesla and his quest for wireless transfer of electricity.

 

[Faez]

No! A study of RF "radio frequency" magnetic energy would explain why this isn't possible. First RF is AC and would need rectifying to DC by using a sensitive diode such as a germanium one as seen in the crystals sets of old. Also a coil would be needed to tune the antenna to a loud signal IE a crystal set. The DC electricity produced would go to the battery rather than the headphones and would be micro-millamps at best and probably just a few volts.

In other words, a signal is required to make electricity flow in an antenna and flows only near or in resonance with the broadcast signal. The broadcast signal would have to be a steady 24/7 tone or else the voltage would fluctuate and so would the micro millamps. The voltage and micro mills fluctuate with modulation.

Generating electricity is a simple concept but it does require converting other forms of existing energy. The new age idea that one can pull usable household electricity out of the air for free is bunk.

 

[Faez]

No tickle charging a bank of batteries out of that I guess. I was hoping the loop could draw in natural electricity. Art Bell spoke of having to have a special ground to keep his from knocking him on his butt!

Art Bell was talking about having a ground on his high-power transmitting antenna so the TRANSMITTED RF didn't burn him. It is just like a Tesla coil, an input is required. You can tranform voltage up, but when you do you reduce amperage. You will always get less wattage out than is put in. There are always losses in converting electricity.

The only free electricity is lightning. The problem arises in how to harness it and then store it. It would take a silicon rectifier the size of Texas and batteries from Texas to the East coast.

For home use, the best way and most environmentally friendly way to produce electricity is with a high-efficiency alternator and a bank of nickel-iron batteries. Mount it on a bike. I once proposed the idea for gyms to have these setups and they could sell electricity. Have both arm and leg-driven generators and forget all the other junk. Get in shape and produce electricity.

 

[Neb]

Art Bell was talking about having a ground on his high-power transmitting antenna so the TRANSMITTED RF didn't burn him. It is just like a Tesla coil, an input is required. You can tranform voltage up, but when you do you reduce amperage. You will always get less wattage out than is put in. There are always losses in converting electricity.

The only free electricity is lightning. The problem arises in how to harness it and then store it. It would take a silicon rectifier the size of Texas and batteries from Texas to the East coast.

For home use, the best way and most environmentally friendly way to produce electricity is with a high-efficiency alternator and a bank of nickel-iron batteries. Mount it on a bike. I once proposed the idea for gyms to have these setups and they could sell electricity. Have both arm and leg-driven generators and forget all the other junk. Get in shape and produce electricity.

An elite athlete can produce 1/10 hp for a sort period of time. That is about 74 watts.

Ben

 

[Faez]

An elite athlete can produce 1/10 hp for a sort period of time. That is about 74 watts.

Ben

The bicycle generator is a good resource for emergency backup 12-volt battery charging for a system that has a draw-in milliamps. It would be almost useless other than for charging batteries for led lighting.

For a constant 1 amp charge, I used a waterwheel driving a small alternator. I didn't have enough hydropower to drive a turbine which would be my choice for producing total household electricity at 240/120 volt AC.

Solar power is the best way to go, but so much expense, upkeep, and inefficiencies. If I was younger I would go back to less dependence on electricity except for lights which would be all LEDs with reflectors. My idea is to simplify and learn to live with less.

 

[Magus]

So recap.
I can't draw electricity, natural or otherwise out of the air EXCEPT with a crystal radio? but it seems logical if it powers a speaker, it can trickle charge a battery? but if you can't you can't. I knew I'd look dumb asking.

 

[SheepDog]

The crystal radio you talk about never used a speaker unless it had a powered amplifier. They used a 2K ohm ear phone.

 

[Faez]

Maybe it's rural legend or maybe not , I remember a story about a farmer who put in a serious amount of wire directly under a high voltage transmission line and was producing useable power. The power companies monitor things quite closely and they busted him.

Legend! All that could be picked up that way would be high-level RF static.

 

[Neb]

Legend! All that could be picked up that way would be high-level RF static.

Agreed.

The three wires carry 3 phase which are 120 out from each other. On the ground the fields cancel out. Enough to muck with AM radio if the station is near a harmonic of 60 Hz.

Ben

 

[Faez]

So recap.
I can't draw electricity, natural or otherwise out of the air EXCEPT with a crystal radio? but it seems logical if it powers a speaker, it can trickle charge a battery? but if you can't you can't. I knew I'd look dumb asking.

Crystal sets with big resonant coils and long wire antennas receiving loud signals would produce enough power to drive magnetic headphones at a low volume, but the sets with small ferrite core coils and short antennas required a crystal headphone that worked with very low driving power.

A crystal or dynamic microphone also produces an electrical current, but not enough to be of any use other than to drive an amplifier.

 

[Faez]

Does anyone remember the Facebook ad that showed a 2 meter J pole antenna made from copper pipe and claimed it could produce electricity and power your house for free after you bought their plans on how to make it? I reported that ad several times before they pulled it and I can't believe people actually bought their plans. It was a scam out of China so they couldn't be brought to justice. Free electricity that will power your entire house is a scam unless you are living in the White House and then someone else is paying for it, hahaha!