"AndyS" wrote in message
...
Andy writes:

I remember from 50 or so years ago reading a copy of POP
electronics, or
maybe ELEC illustrated, which featured a couple of young boys named
Carl
and Jerry and the stuff they messed about with each month. Kind of
like
a "Mr Wizard" story.....

One of the articles was winding a coil of wire around a plastic
bottle of
water and exciting it , then watching the output from the coil as "the
water
molecules oscillated"...... I don't remember the details, but they
called
the affair a "differential proton magnetometer", and used it to
measure
magnetic fields....

Does anyone else here remember this article, and do you have any
means
to clarify the method, and possibly the practice ?

Being retired, I have a lot of time on my hands to do experiments,
especially
simple ones, and I thought it would be a hoot to explore this for a
day or
two. However, I don't remember enough details to be able to put
together
a proof of concept in my workshop...

Thanks in advance for anything anyone here can suggest...

Andy W4OAH in Eureka, Texas

The one you want is from April 1964 Popular Electronics. There are many of
them here, but not the one you want.
http://home.gwi.net/~jdebell/pe/cj/cnjindex.htm


What they did was to wrap a plastic baby bottle full of water with a lot of
wire. Then it was hooked to a switch so a battery could be placed across
the coil for a second or so. Then it was switched to a high gain amp and
into the vertical channel of an oscilloscope. The horizontal channel was
fed with an oscillator of around 2000 to 2500 Hz. The osicllator was
adjusted so a circle was displayed on the scope. This was the self resonate
frequency of the water molecules or whatever in the bottle. When the bottle
was passed over an object the circle would spin or change indicating the
frequency of the bottle had changed.
I must have been about 14 years old when I read this.