[geeks] While on the subject of weirdness

[Francois Dion]

On 8/7/05, James Fogg <James at jdfogg.com> wrote:
> > I got a real puzzler, and the only lead I had was a HAM's (Nyle
> > Steiner) web site, but haven't heard anything back from him
> > so I'm assumed he has changed email. In the meantime, I've
> > contacted many radio geeks, electronic wizs etc. I figured
> > I'd give it a shot on the Geeks list, with all the
> > electronics posts we've had recently.
> >
> > In short, I'm getting radio reception out of a little puddle
> > of salty water, a copper wire and a piece of aluminium. But
> > there is much more to the story.
>
>  It sounds like you have an accidental diode detector.

Yes, that's what I was thinking, but what I want to figure out is what
makes the diode. That's the real interest for me. I'm wondering if
maybe the salt creates a "liquid crystal" in between the alu and cu.
Or maybe simply it starts working when there is enough oxydation and
that would be the diode detector.

> Add an LC network
> or Pi network and you might be able to tune to specific frequencies.

Unfortunately, as water evaporates and as salt crystal and oxydation
forms on the metal, the circuit properties change wildly.

> The
> rocket science website describes the accident that led to their
> discovery, how did you stumble upon it?

That's my website and how I stumbled upon it :)

The other site (Nyle Steiner) I found is this:
http://home.earthlink.net/~lenyr/

It has to be one of the most geekiest website out there, the guy even
made his own vacuum tubes. I'm not sure if Nyle Steiner is THE Nyle
Steiner that made the Steiner Parker Synthacon.

> With an AM signal generator and an oscilloscope you might be able to
> determine if you have a diode detector. In my youth (30 years ago - my
> god!) I played with crystal and cat's whisker detectors and learned some
> surprising things will detect. A ham friend of mine who used to operate
> at legal maximum (1500 watts) using AM told me his neighbor complained
> that their toaster used to detect his signal and they had a "talking
> toaster".

That is very cool.

> The presence of AL and CU in a brine could do several things, but a
> chemist would know. Some things I'd look for are galvanic action,
> oxidation (an easy semiconductor source for a diode)

I think that's probably it.

> and possibly a
> electro-chem reaction that makes a battery (two dissimilar metals in
> acid will do this, maybe the brine in contact with one of the metals
> changes the PH).

Right. Before I got an actual radio signal, that's what I tought it
was, and that's what Nyle's site was sort of hinting to, but he did
mention the noise had structure. I tought it was the "order in chaos"
of the chemical reaction itself. It would be quite interesting to get
some input from a chemist geek.

> Could you perhaps diagram everything needed to reproduce your "circuit".

I really need to take a picture too.

> I think I might be getting the old radio bug back. It might be time for
> me to play again.

Francois