From: SFPhysics@aol.com
Date: Sun Dec 05 1999 - 01:17:06 PST
From: SFPhysics@aol.com Message-ID: <0.9981b45b.257b8792@aol.com> Date: Sun, 5 Dec 1999 04:17:06 EST Subject: Cell Phone Experiment
One of the experiments I always enjoyed having the students do involves radio
frequency electromagnetic wave propagation. I have not updated this to the
cell phone age but when there were hand held CB's at 27MHz we would take a
high frequency RF signal diode to rectify the RF for a DC component in
conjuction with either a tank circuit or an antenna dipole and the students
would measure the output with a sensitive meter. It was good for teaching
the inverse square law, polarity of wave propagation, resonant parallel RLC
circuits, and a number of other related phenomena. This might work with the
450MHz cell phones but the new high band GHz phones probably would not be
detectable.
I think one of the Forrest Nims III project books from Radio Shack has a
"field strength meter" circuit similar to the ones I used eons ago in the
stone age.
Best to the list,
Al Sefl
p.s. Pardon my omission of the store name with the DMMs and Laser Pens. It
is Harbor Freight Tools. My computer went down and when it was resurrected
Sunday at 1AM I found a few messages enlightened me to my missing just that
one detail.
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