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Is this for real or a crock?

PostPosted: Sun Jan 29, 2012 6:25 pm
by phild05

Is this for real or a crock?

PostPosted: Sun Jan 29, 2012 6:43 pm
by smeggypants
that circuit looks like a voltage mutiplier. they use a version with more steps to make ionisers and electric fences.

Watt ( pertinent pun ) that video is showing, if the antenna wire isn't connect to a voltage source is probably and electric charge in the air being voltage multiplied.

Problem is it's only voltage. the amount of current is bugger all. to get anything beneficial you need free 'power' not free voltage.

Verdict: misleading, unless I'm missing sonmething :)

Is this for real or a crock?

PostPosted: Sun Jan 29, 2012 8:39 pm
by Mr Squirrel
Why did i read the thread title as "Is this a real or dead cock?" :rofl:

Is this for real or a crock?

PostPosted: Sun Jan 29, 2012 9:22 pm
by smeggypants
Mr Squirrel wrote:Why did i read the thread title as "Is this a real or dead cock?" :rofl:


Freudian slip :rofl: :rofl:

Is this for real or a crock?

PostPosted: Sun Jan 29, 2012 10:33 pm
by Channel Hopper
Probably lives under power lines

http://www.youtube.com/watch?v=cXhZvyGt ... re=related

If you make/utilise an antenna (or stick anything in the air) you can blag power.

Is this for real or a crock?

PostPosted: Mon Jan 30, 2012 6:18 am
by Richie
Going to breadboard this as soon as I get hold of some 1n34's. I know those diodes can pick up and generate power from radio waves, as they are used in basic crystal radios (which require no batteries, yet power a simple earpiece).

However, I have a feeling it might produce a few volts, but I doubt there will be enough current there to even light an LED.

I'll post the results once I get the parts, but not holding my breath.

Crystal Radio (using a germanium diode)
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Is this for real or a crock?

PostPosted: Mon Jan 30, 2012 6:30 am
by smeggypants
You'll be able to pick up Hilversum and the Voice Of America! :thumb:

My dad made a crystal set in the 1930s [ :eek: - that is so long ago!!! ]

Is this for real or a crock?

PostPosted: Mon Jan 30, 2012 6:40 am
by Richie
smeggypants wrote:You'll be able to pick up Hilversum and the Voice Of America! :thumb:

My dad made a crystal set in the 1930s [ :eek: - that is so long ago!!! ]

First circuit I ever built, aged 9 (still building gear now).

In the '30s, it would likely have used a "cat's whisker" detector, the germanium diode was a later substitute.

Is this for real or a crock?

PostPosted: Tue Jan 31, 2012 1:18 am
by smeggypants
Richie wrote:
smeggypants wrote:You'll be able to pick up Hilversum and the Voice Of America! :thumb:

My dad made a crystal set in the 1930s [ :eek: - that is so long ago!!! ]

First circuit I ever built, aged 9 (still building gear now).

In the '30s, it would likely have used a "cat's whisker" detector, the germanium diode was a later substitute.


Ahh Cats whisker, that rings a bell. :thumb:

Btw, Zapaxe was on about getting free power from the telephone line a while ago. I think you can get a few milliamps to charge up batteries :)

Is this for real or a crock?

PostPosted: Tue Jan 31, 2012 1:50 am
by Richie
smeggypants wrote:
Richie wrote:
smeggypants wrote:You'll be able to pick up Hilversum and the Voice Of America! :thumb:

My dad made a crystal set in the 1930s [ :eek: - that is so long ago!!! ]

First circuit I ever built, aged 9 (still building gear now).

In the '30s, it would likely have used a "cat's whisker" detector, the germanium diode was a later substitute.


Ahh Cats whisker, that rings a bell. :thumb:

Btw, Zapaxe was on about getting free power from the telephone line a while ago. I think you can get a few milliamps to charge up batteries :)

I remember reading something about voltage that is sent through the telephone cables, for some reason 48V springs to mind, and I'm not sure how far out of the exchange this voltage continues. It was back in the '80s when I read this, so things may well have changed. In any case, it would be enough to power a studio mic, although I wouldn't be keen to fire up a brand new U87 off it, not without putting it through a room full of capacitors anyway.

Is this for real or a crock?

PostPosted: Tue Jan 31, 2012 3:03 am
by smeggypants
Richie wrote:
smeggypants wrote:
Richie wrote:
smeggypants wrote:You'll be able to pick up Hilversum and the Voice Of America! :thumb:

My dad made a crystal set in the 1930s [ :eek: - that is so long ago!!! ]

First circuit I ever built, aged 9 (still building gear now).

In the '30s, it would likely have used a "cat's whisker" detector, the germanium diode was a later substitute.


Ahh Cats whisker, that rings a bell. :thumb:

Btw, Zapaxe was on about getting free power from the telephone line a while ago. I think you can get a few milliamps to charge up batteries :)

I remember reading something about voltage that is sent through the telephone cables, for some reason 48V springs to mind, and I'm not sure how far out of the exchange this voltage continues. It was back in the '80s when I read this, so things may well have changed. In any case, it would be enough to power a studio mic, although I wouldn't be keen to fire up a brand new U87 off it, not without putting it through a room full of capacitors anyway.


I think the nominal voltage on the line is indeed 48V. It's that high to cope with the higher restistences of miles of coper wire.

The same reason the mains voltage is stepped up to 400,000V in overhead cables ( pylon job ). As well as needing much lighter cables for the same power, there's a lot less voltage drop with less current ( V=IR )

The load ( telephone ) will also drop the voltage as that increases current flow as it uses leccy.

The voltage, apart from powering the phone, is also there as an indicator of the state of the line. Voltage drops when off the hook amd much higher when it's ringing

Is this for real or a crock?

PostPosted: Tue Jan 31, 2012 11:50 am
by Channel Hopper
Richie wrote:
smeggypants wrote:You'll be able to pick up Hilversum and the Voice Of America! :thumb:

My dad made a crystal set in the 1930s [ :eek: - that is so long ago!!! ]

First circuit I ever built, aged 9 (still building gear now).

In the '30s, it would likely have used a "cat's whisker" detector, the germanium diode was a later substitute.



When I started building stuff, the cats whisker was a piece of coke and the head of a picture frame nail pushed onto the surface.

Combining the two pieces of technology together though, the finger stop tab of an old style phone could be used as the antenna connection, since the internal circuitry meant there was no direct path to earth.

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