Zenith Model A2A "Radionic" Vacuum Tube Hearing Aid
The Zenith Model A2A "Radionic" vacuum tube hearing aid was manufactured
by the Hearing Aid Division of the Zenith Radio Corporation of Chicago,
IL beginning in October, 1942. This was Zenith's first wearable hearing
aid. (The previous model was a table-top unit.)
The black plastic case measured 5⅛” by 2¾” by ⅞” thick, and weighed 7⅞
oz. without the batteries. (Zenith also made a pink plastic model as
well.)
The microphone grill is the series of 9 horizontal slots (top center)
behind the pocket clip. Notice the large "Z" on the lower front face.
This was a two-piece hearing aid as it connected to external
batteries (battery cords bottom left). The magnetic receiver is at the
bottom right.
The Zenith Model A2A used two vacuum tubes.
It was sold through drug stores and jewelry stores for $40.00. |
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Top view of the Zenith Model A2A showing the 4-position (2, 3, 4 and the
lever straight up for position 1) tone control (left), the large volume
control wheel (center) and the on-off switch (right).
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Inside view of the inside of the Zenith Model A2A showing the two
vacuum tubes it used at the bottom. The shiny round "thing" in the
middle is the microphone. Essentially, it was a loud speaker that worked
"backwards". At the top left is the tone control, in the
center is the volume control, and at the top right is the on/off switch.
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Close-up front view of the inside of the Zenith Model A2A showing the two
vacuum tubes it used. The one on the left has pins, while the one on the
right has leads soldered in place. The one on the left measured
1 5/8" x 11/16" (4.2 x 1.8 cm) in diameter. The one on the right
measured 1 3/16" x ½" (3.7 x 1.3 cm) in diameter.
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Close-up rear view of the inside of the Zenith Model A2A showing the two
vacuum tubes it used. The one on the left with the leads is a Raytheon
CK 511 X.
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Bottom view of the Zenith Model A2A showing the battery jack (left), and
the receiver jack (right). The "butterfly" in the middle swivels 90
degrees to hold the plugs in place. You couldn't accidentally put the
plugs in the wrong sides because the "pins" were off center (see two
below pictures).
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Close-up view of the Zenith Model A2A battery plug. The battery plug had
the heavy battery wires attached to it.
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View of the box and replacement battery cord for the Zenith Model A2A.
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Close-up view of the Zenith Model A2A receiver plug. The receiver plug
had the thin receiver cord attached to it.
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Close-up view of the Zenith Model A2A receivers and ear tips. The
black receiver (top left), the clear plastic ear tip post (right of
receiver) and the rubber ear tip (right of plastic post) all snapped
together as shown with the pink receiver and parts assembled (top
right). The Model A2A came with a variety of sizes of rubber ear tips
(bottom left) and a variety of sizes of ear tip posts (bottom right). |
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Close-up view of the Zenith Model A2A battery plugs. The 3-pronged plug
went into the "B" battery (left) and the 2-pronged plug fit the "A"
battery (right).
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View of the Zenith Model A2A hearing aid with both the "B" and "A"
batteries attached. This whole assembly weighed a whopping 1½ pounds!
The
Zenith Z-30 "B" battery (left) put out 45 volts, while the
Zenith Z-1 "A" battery (to the
right of the "B" battery) put out the usual 1½ volts.
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Back view of the Zenith Model A2A hearing aid. The two slots (top
center) are for the pocket clip. It could be attached to the front as
shown in the top picture, or attached to the back via these slots.
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Close-up view of the back of the Zenith Model A2A showing the
information engraved there. It reads, "ZENITH RADIO CORP. U.S.A.",
"MODEL A2A" then gives the serial number and patent info.
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The Zenith Model A2A "Radionic" hearing aid in its original box. |
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Top view of the Zenith Model A2A "Radionic" hearing aid's original box.
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