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It's already been prototyped, Eric, about 125 years ago. :-)  Still a good
device.
Alexander Graham Bell also invented the photophone in 1880, just a couple of
years after it was discovered that selenium changed its resistance depending
upon its exposure to light.  There are drawings of what he made that I used
to make a look-alike copy for a communications exhibit  we did at the
Franklin around 1986.  I used Mylar as a 2" diameter membrane vibrated by
visitors
voice.  The light source was a spot and the receiver was a cheap solar cell
connected to an amp.

I just love google!  Here's a working drawing from Alexander himself!
http://www.americaslibrary.gov/jb/gilded/jb_gilded_bell_2_e.html
Looks like one of mine- "thinking" drawings like this one are almost always
crude.

The thing I built was based on his transmitter seen here.
http://www.bell-labs.com/org/physicalsciences/timeline/span2.html#
We had better line drawings of it to go by; they must exist somewhere.

----- Original Message -----
From: "Eric Siegel" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, March 30, 2004 2:52 PM
Subject: Re: Telecommunications activities

.

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