antenna to the AC voltmeter.
For the antenna, a 15-foot-long extension cord can be
used, or any other insulated wire of roughly that length.
For the first experiments, it can be stretched out on the
floor of your home, maybe extending into another room.
A "quiet" ground is needed, to avoid picking up stray
voltages that are not electromagnetic in origin. It should be
noted that the "return" or "neutral" wire of 120 volt AC
power lines (color coded white in the US) is not suitable,
because it often has considerable voltage on it, due to
resistive ground connections. Using
that would be cheating, if we are investigating the power that comes strictly
from EMFs in the air. Similarly, the
green coded safety connection might
have about 10 volts on it — relative to
true ground — if a clothes dryer or air
conditioner is running nearby. For these
experiments, a better ground connection can be obtained by hammering a
bare metal curtain rod into the earth
and attaching a clip lead to it.
The meter to measure the AC
voltage can be any instrument with
an input impedance of around 10
megohms, such as a portable digital
multimeter. This could also be used
to serve as the ammeter and DC voltmeter shown in Figure 1, if it is disconnected from position S1 and then
reconnected at S2, and later at S3.
Alternatively, of course, separate
meters could be used.
A full wave diode bridge can rectify the input, as shown. However,
good results can be obtained with just
diode D1, with a plain wire in place of
D3, and no connections at all in positions D2 and D4.
The LED should be a low current
type, such as RadioShack catalog
number 276-044, which will produce
visible light with only two milliamps.
The Tungsten incandescent bulb also
has to be a low current type, such as
RadioShack catalog number 272-
1139 or similar, which will light up
with only 20 mA. The transformer
can be a step-down 120-volt to six-volt power supply type, which we will
operate "backwards," in a 20:1 step-up mode. Switch S6 (or just an ordinary clip lead) is going to be used to
dump the capacitor's charge into the
low voltage winding, and almost any
neon or argon lamp attached across
the high voltage winding will then flash.
The Waves that Surround Us
Unless you are down in an iron mine, you are probably
in a measurably strong electromagnetic field. Even inside
a metal building, there is usually some oscillating field
coming from the 120-volt AC power lines in the walls, just
because of the power that always goes to computers,
"instant-on" TV sets, and even the multiplicity of electric
Circle #122 on the Reader Service Card.