John Bell & Croyden Vacuum Tube Hearing Aid
This table model or box-style vacuum tube hearing aid was made by
(for?) John Bell & Croyden of London England.
The date of manufacture is unknown, but it is similar to other hearing aids of the same style manufactured in the
mid to late
1930s. This style of hearing aid had self-contained batteries and was
made to resemble the box cameras of the day. It could be set on a table
or carried by hand.
This hearing aid measured 6⅛" wide x 4⅝" high x 3⅞” deep, and weighed 1 lb, 13 oz.
without the batteries.
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The only name visible on this hearing aid is located on the inside of
the battery door. The name reads "John Bell & Croyden/London W. 1."
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View of the front panel of the John Bell & Croyden vacuum tube hearing
aid showing the controls. The chrome on-off/volume control is at the
top center and beside it is the earphone jack (top right). Notice the interesting arrangement of the earphone
jack. There was
one male pin and one female socket on the plug. There would be a
corresponding female socket and male pin on the earphone cord that
plugged into it. This curious pin arrangement was
common on English hearing aids of this period. Missing is the earphone
and headband.
The large microphone grill is at the bottom center.
At the left center is the sliding door latch which opens to access
the battery compartment.
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View of the battery compartment of the John Bell & Croyden
vacuum tube hearing aid showing the
John Bell & Croyden branded "B" battery. This battery weighed a
hefty 13 oz. Likely the "A" battery weighed about the same. The "A"
and "B" batteries took up half of the
internal volume of the hearing aid. The red and black "B" battery plugs
are shown hooked up to 32 volt "B" battery. The "A" battery
terminals are at the bottom center. The "A" battery must have been
approximately the same size and shape as the "B" battery.
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Side view of the electronics module of the John Bell & Croyden
vacuum tube hearing aid showing the volume control (top left),
microphone (bottom left) and the three vacuum tubes (right).
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Top view of the electronics module of the John Bell & Croyden
vacuum tube hearing aid showing the three vacuum tubes (left),
capacitors (2) (top right) and transformer (bottom right). |
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Close up of one of the vacuum tubes and its socket of the John Bell & Croyden
vacuum tube hearing aid showing the unusual "pin" design of these tubes. |
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The tubes used in this John Bell & Croyden vacuum tube hearing aid
were made by Osram, a British firm.
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