The third floor of the Museum of
Communications houses telephone switching equipment, old teletype
equipment, and other old artifacts. The following is a picture gallery
of the third floor.
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Third Floor Page 1
recording technology has been around for a number of years. The first
practical uses were magnetic wire recorders.
a reel-to-reel magnetic tape recorder. Modern tape recording was
invented shortly after World War II
leave your message after the tone.. tone… tone.. tone. This is an
early answering machine (Western Electric made, of course). The
outgoing message was on a 45 RPM record, the incoming message on
is also from the “you’ll never know what you’ll find” department. This
is a poster for Alascom, which was at one time the name of the largest
telephone company in Alaska. Since this time, Alascom has been bought
out at least two or three times.
cables have been a challenge for many years. Here are some early
examples of how telephone engineers of yesteryear were able to meet
computers and radios. Hey Bruce – is your old CB radio in this
you wash me now? Again, Western Electric branched out and even did
home appliances. This is an old washing machine from around 1920.
you hear me now? Now? And again? Here’s an old hearing test kit that
used phonograph records to create the tones, instead of
A sign for the (then) forthcoming 5ESS switch. Basically the bread and
butter digital end office switch that Western Electric introduced in
1982 and Lucent still makes to this day.
the invention of the photoelectric cell and films with emebedded
soundtracks, here’s an experimental soultion – using a phonograph
record with a projector. I’m not sure how they were synchronized, if
– the telephone switches. Unfortunately, I didn’t take any pictures of
the Number 1 Crossbar (#1XB) or Panel, but I took a number of pictures
of the Number 5 Crossbar (#5XB).
associated with the #5XB switch.
relays associated with the incoming register.
sign that helps describe the #5XB switch and a Touch-Tone to frequency
conversion table. (where was the sign for multi-frequency tone
Look at all the cabling inside all those racks!
the test board for the #5XB. I made a few calls from here to the #1XB
and Panel switches.
To the left of the picture is the #1XB test board.
The Direct Current Power Board. How are you able to
control the electrical power required for a large central office? Very
carefully! At 48 volts DC and over 1000 amps, this system controls the
power board for adding additional batteries when the main AC power
goes out, without short circuiting the system while batteries are
added or removed, or adding or removing the emergency generator from
small cord board operator station.
emergency phone for use by the police. This was used before there were
radios in police cars.
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Page last modified December 20, 2008
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