Yagi antenna applicability

[raschen]

I read a story by an "old timer" radio buff. He mention that the neighbors sons not having much as far as resources had a radio set that ran off of a battery. They took a discarded cable from a nearby radio station and strung it out. Attached one end to a high place like a tall pole, and attache the other end to a spark plug. The opposite end of the plug was attached to the + of the dead battery and the ground on the battery was grounded.

Over a period of a few days a dead battery would be charged. And they would listen to the radio again. wash and repeat.

The cable they used probably was coax of some sort acting like a capacitor which would discharge across the spark plug gap into the battery..

I guess it would work... how that connects to yagi's I don't know. Other than being an antenna.

I drew a obscure if anything parallel between the poles of a yagi antenna and the plates of a electrolysizer.

The yagi antenna uses spaced radiators or different lengths to cause a resonance.

nice image located here http://www.mtmscientific.com/yagi.HTM

but only one of the radiators is actually connected to a circuit. The longest on the end acts as a reflector for the "real" radiator next to it. The others resonate the rf or em.

Also.... in watching the java applets at mit about how dipoles radiate.
http://ocw.mit.edu/ans7870/8/8.02T/f04/ ... e_320.html
wmv files at the bottom of page

the radiation pattern has a nice pulse and contraction pattern. Kinda looks like push pull.

Thought this would provoke some interesting possibilities or thoughts. I think it's pretty cool the way resonance, frequency, energy and all the other spagetti noodles all lay on top of each other.

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this is not hydrogen or electrolysis related so was moved to OU General Discussions

moderator
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[coffeyw]

They were using atmospheric charge to recharge their battery. (Nothing to do with radio signals or resonance)
The atmosphere has an average charge of 1,000 volts per foot above ground level.
If those boys managed to put that wire up to a level of 30ft, they'd be able to collect a charge of up to 30,000 volts.
If they were using an antenna to help collect the charge, the antenna would have to be insulated from ground.
The larger the antenna, the faster they could collect that charge.

Some folks use a transformer to step the voltage down and get a higher useable current to charge their batteries.
Use a bridge rectifier on the low voltage output of that transformer.

Coffey

[Bob Boyce]

Coffey is right.

I did the same thing with a long wire stretched between ceramic insulators, terminating into a spark gap. The other side of the spark gap was fed into the HV secondary of an ignition coil. The ignition coil was left ungrounded (the cold side of the secondary is tied to one side of the primary in most single tower ignition coils) so the flow had to discharge through the HV secondary and through the primary to the + terminal of the battery through a rectifier. The - of the battery was grounded. Every time the plug fired, there was a HV/low current spike, and a lower voltage/higher current spike, into the battery. A typical automotive ignition coil has a secondary:primary winding ratio of near 100:1

An improvement on that design yielded even better results. By using 2 spark gaps, and a Leyden jar from the point where the gaps meet to ground, potential was allowed to remain on the antenna wire, improving the "electret effect" and subsequent charge collection. In this configuration, the hot side gap was narrower and fired more frequently, charging the Leyden jar. Then when sufficient charge had accumilated, the second gap would fire, discharging the Leyden jar into the coil. The result was a much greater collection of energy.

Bob

[raschen]

I thought it would have been kinda on topic... rekon I left a bit much out. Sorry about that.

The addition that would have made it on topic.... which I forgot to add in a twitch of pauses.

Connecting an antenna of sufficient length to a series of cells. Do you think the series of cells would act like a tuning circuit for an antenna?

Tuning circuit would be a capacitor, coil and resistor. Or many varients of that.

The plates in a hydroxy cell would act as a capacitor... the electrolye as resistance?? Would the whole thing be considered a coile?

I had bobs welder unit in mind when hashing through this.

Another take on the antenna theme, would be for example bob's welder unit... reducing the plate size and adjusting the spacing in a manner similar to the yagi antenna construction and then applying current/voltage/signal to the radiating plate.

Should induce a resonance dontcha think?

Bob if your still there.... do you know what the chladni pattern of the plates in your welder looked like? Don't know why... but I'm very interested in what they would look like.

Was reading about transformers in "Elements of Radio" book. Didn't quite grasp the math of how the current was increased when reducing the voltage. Anybody got some averages... kinda like small-medium-large averages with some math...

If the voltage that was stepped down to increase the useable current was fed into a hydrogen producing cell series... would it be beneficial to skip the bridge rectification?

Did you have to balance the dual spark gaps Bob? To cause them to fire at the same time? Oh my head is hurting with thinking about that one. ish.

[coffeyw]

Transformers have ratios like gear boxes.
1 to 1, 2 to 1, 5 to 1.
A 5 to 1 ratio could represent a transformer with 500 turns of wire on the primary and 100 turns of wire on the secondary.

The formula for converting a certain level of current and voltage in the primary of a transformer to another level of current and voltage in the secondary is based upon wattage.
5 volts at 1 amp = 5 watts
1 volt at 5 amps = 5 watts
The formula is Volts X Amps = Watts (Watts per hour)

Using the figures above, we can determine what a transformer with a 2 to 1 ratio will do to voltage and current.

5 Volts at 1 Amp = 5 Watts
5 Volts at 1 Amp : (2) to (1) ratio
5 Volts / (2) = "2.5" and "2.5" X (1) = 2.5 Volts
5 Watts / 2.5 Volts = 2 Amps
So a 2 to 1 ratio transformer should convert 5 Volts at 1 Amp to 2.5 Volts at 2 Amps.

How about a 1 to 5 ratio?

5 Volts at 1 Amp = 5 Watts
5 Volts at 1 Amp : (1) to (5) ratio
5 Volts / (1) = "5" and "5" X (5) = 25 Volts
5 Watts / 25 Volts = 0.2 Amps
So a 1 to 5 ratio transformer should convert 5 Volts at 1 Amp to 25 Volts at 0.2 Amps.

How about 5 turns of wire "to" 20 turns of wire?

5 Volts at 1 Amp = 5 Watts
5 Volts at 1 Amp : (5) to (20) turns
5 Volts / (5) = "1" and "1" X (20) = 20 Volts
5 Watts / 20 Volts = 0.25 Amps
So a 5 turns to 20 turns transformer should convert 5 Volts at 1 Amp to 20 Volts at 0.25 Amps.

The figures in these examples represent a perfect world view. They don't take into account the resistance of the wire, losses within the transformer core itself, or other inefficiencies such as impedance mismatch, etc....

Hope I got the point across better than I think I have.

Coffey