Radioear "Masterpiece" Carbon Hearing Aid
The Radioear "Masterpiece" carbon hearing aid was manufactured by E. A. Myers of
Pittsburg, Pennsylvania (later Radioear Corp.) beginning in May of 1939.
The complete unit consisted of a carbon amplifier (top center),
battery box (center), receiver (left—ear mold not shown) and microphone
(right). Apart from the receiver, the various pieces were made of black
bakelite.
With the amplifier attached the battery box and amplifier together
measured 5" x 2 9/16" x 1 3/16".
The whole unit (all pieces) including batteries weighed 10 oz.
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The Radioear Masterpiece microphone was 2⅞" in diameter. It
was a carbon
shot microphone—you can hear the shot rattle when you shake it. There
are four tiny holes—2 near the top and 2 near the bottom. If
you look closely, you can see the holes situated between the 2nd and 3rd
lines on the front of the microphone. Their purpose is unknown.
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Top view of the Radioear Masterpiece microphone showing the
on-off/volume control slider switch. Sliding the switch to the left
(right side in picture) turns it off and sliding to the right (left side
of picture) increases the volume. The larger slots around the
circumference of the microphone (left and right sides) are where the sound
entered.
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A close up of the back of the Radioear Masterpiece microphone. The
clip at the top was so you could clip the microphone to your pocket
instead of having to hold it.
Note the two position control (lower center). It's function is
unknown.
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The carbon granule amplifier (left)
plugged directly into the battery box (right). |
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In turn, the microphone and earphone plugged into the carbon
amplifier. The earphone leads plugged into the two top holes, while the
3-pronged microphone plug, plugged into the 3 bottom holes. (Notice the
spacing between the second and third holes so you couldn't plug the
microphone in the wrong end by mistake.) Also the top and bottom holes
are smaller than the others, again making it impossible to plug things
in wrong.
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The carbon amplifier (right) unplugged from the battery box showing the
relative size of both. |
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The battery box with 3 "C" size (No. 935) regular flashlight batteries
in it.
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The
empty battery box showing the battery contacts. The Masterpiece ran on
4½ volts (3 1½ volt batteries hooked in series).
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The end of the battery box showing how the amplifier jack connected
directly to the batteries.
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(If a larger picture doesn't appear, you may have to
turn your pop-up blocker off)
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