Medexport V/O Model 3BYK Vacuum Tube Hearing Aid
The Medexport V/O Model 3BYK two-piece vacuum tube hearing aid was
manufactured by the Moscow Hearing Aid Plant for V/O Medexport of
Moscow, U.S.S.R. in 1950.
The 3-vacuum tube Medexport Model 3BYK vacuum tube hearing aid measured 4⅛” by 2⅜” by
15/16” thick (10.5 x 6.1 x 2.4 cm). Without batteries, it
weighed 5.4 oz. (152 g).
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Front view of the Medexport Model 3BYK vacuum tube hearing aid showing the
black Bakelite case. The microphone grill is at the top. The design is
of a candelabra.
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Close-up view of the upper front of the Medexport Model 3BYK vacuum tube hearing aid showing the
microphone grill in the shape of a candelabra. Note part of the grill on
the left side has broken off.
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Close-up view of the lower front of the Medexport Model 3BYK vacuum tube
hearing aid showing the model number (3BYK).
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Top view of the Medexport Model 3BYK vacuum tube hearing aid showing the
on-off switch (lower center).
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Left side view of the Medexport Model 3BYK vacuum tube hearing aid
showing the control wheel (left). This control is unmarked, but
probably it was for the volume.
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Right side view of the Medexport Model 3BYK vacuum tube hearing aid
showing the control wheel (right). This control is unmarked, but
probably it was for the tone. (Or I could have it backwards and this is
the volume control and the tone was on the other side.)
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Rear view of the Medexport Model 3BYK vacuum tube hearing aid showing
the pocket clip (upper center) and plugs (bottom).
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Close-up view of the center back of the Medexport Model 3BYK vacuum tube
hearing aid showing the serial number (6949337) and other manufacturer's
information (in Russian).
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Bottom rear view of the Medexport Model
3BYK vacuum tube hearing aid showing the receiver cord plug (left) and
the battery cord plug (right) when plugged in.
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Close-up view of the bottom rear of the Medexport Model 3BYK
vacuum tube hearing aid showing the receiver cord sockets (left) and the
battery cable sockets right.
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Close-up view of the receiver cord plug (bottom) and socket (left side)
of the Medexport Model 3BYK
vacuum tube hearing aid. Note, the receiver cord only needed two pins,
so two were unused.
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Close-up view of the battery cable plug (bottom) and socket (right side)
of the Medexport Model 3BYK
vacuum tube hearing aid. Note, the battery cable used all four pins—two
for the "A" battery and two for the "B" battery.
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Close-up view of the battery cable plugs of the Medexport Model 3BYK
vacuum tube hearing aid. The "B" battery plug is on the left and the "A"
battery plug is on the right. As was true of all vacuum tube hearing
aids, this hearing aid used a 1˝ volt "A" battery
such as the
Eveready 1052-P. It used a 45 volt "B" battery such as the
Eveready
455-P. |
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Close-up view of the two-prong "A" battery plug of the Medexport Model
3BYK vacuum tube hearing aid showing the two pins. Note the right one is
larger than the left one to maintain proper polarity.
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Close-up view of the 3-prong "B" battery plug of the Medexport Model
3BYK vacuum tube hearing aid showing its 3 pins. The 3-pin arrangement
meant you could only plug it in one way, thus maintaining proper
polarity. By convention, "B" batteries had 3 pins although the battery
only used 2 of them. |
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Close-up view of the end of the receiver cord of the Medexport Model 3BYK vacuum tube hearing aid aid showing the
pits at the end of the cord that plugged into the receiver. (The receiver
and ear mold are missing.)
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