Micronic Model 303 Vacuum Tube Hearing Aid
The Micronic Model 303 one-piece vacuum tube hearing aid was made by
Micro-Electronic Products, Inc. of Boston, MA in 1950.
The Micronic Model 303 vacuum tube hearing aid measured 3½” by 2¼” by
13/16” thick (8.9 x 5.7 x 2.0 cm). Without batteries, it
weighed 3.2 oz. (90 g).
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Front view of the Micronic Model 303 vacuum tube hearing aid showing the
attractive light gold-colored aluminum front. The microphone grill consisted of
5 short
horizontal slots (upper front). To the right of the microphone grill was the Micronic logo—a crowned
"M".
Note the pocket clips on each side (near the top). |
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Top view of the Micronic Model 303 vacuum tube hearing aid showing the
on-off/3-position tone control (left), the two receiver cord jacks
(center) and the volume control wheel
(right).
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Side view of the Micronic Model 303
vacuum tube hearing aid showing the pocket clips on the side. (Later
versions of the Model 303 had the pocket clips on the front.)
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Rear view of the Micronic Model 303 vacuum tube hearing aid showing the
black metal back with
swing down battery door (lower half).
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Rear side view of the battery compartment of the Micronic Model 303
vacuum tube hearing aid. The battery door swung down and out.
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View of the inside of the battery door of the Micronic Model 303 vacuum tube hearing aid showing
the make (Micronic), model number (303) and place of manufacture
(Boston, Mass).
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Close-up view of the battery compartment of the Micronic Model 303
vacuum tube hearing aid. This hearing aid used a 1½ volt "A" battery
such as the
Eveready 1015E and a 22½ volt "B" battery such as the
Eveready
412E. |
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The Micronic Model 303 vacuum tube hearing aid was rather unusual in
that it had not just one, but two receiver cord jacks. The upper jack
was for plugging in a magnetic receiver and the lower one was for
plugging in a crystal receiver (or possibly vice versa). |
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View of the Micronic Model 303 vacuum tube hearing aid showing the
receiver cord and two-prong plug (receiver missing).
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View of the Micronic Model 303 vacuum tube hearing aid in its original
carrying case.
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Outside view of the Micronic Model 303 vacuum tube hearing aid's
carrying case.
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