The Ghostbusters Giga-meter
The peripheral top part was built to be removable so
that this prop could be seen in more than one
configuration. Construction is unknown as to what
most of this was. On the replica seen here I used
acrylic and styrene. The shape follows the basic shape
of the body with some added details. On the top is
seen a red window that displays numbers . The
details seen on either side of the peripheral are
identical to the switch cover on the main body. The
two probes that stick out the front are Realistic Stereo
Electret Microphones model #33-1065 these were
gutted and pieces of red theatrical lighting gel placed
inside. Four lights were placed inside each
microphone and sequenced. The microphones also
rotated an 1/8 of a turn towards the sides and then
back again by a set of gears and a motor.
Some finishing touches were to add an outer dome to
the scan head to protect it. Around this dome was
placed a cage in the form of an X to hold the dome in
place. Inside the dome was placed a collar to hide and
augment the spinning dome's gap. A switch was
placed on the back side of the body as an all off/on
switch and another under the handle as a trigger.
Another control was placed on the main body just
about dead center and to the left. The switch caps that I
touched upon earlier are nothing more than a rod with
a step up in the center. On the front of the handle the
step was removed and a piece of tank tread attached.  
The last piece is a faux thumbwheel within a guard,
typically seen on a lot of scientific equipment.
Finally here we have the finished prop replica:
Giga-meter page 5