Saturday, August 25, 2018

Are 1/3 A size batteries suitable for vacuum tube hearing aid amplifiers?


At your risk. Batteries can be dangerous. Take all safety precautions.


Many electron tube amplifier hearing aids used an RM-1 1.4V mercury battery for the direct filament cathodes:


https://www.hearingaidmuseum.com/gallery/Miscellaneous/Batteries/Mallory/info/batterymalloryrm1.htm


Obviously due to mercury something else is needed.


AA size is the ordinary size so many equipment use. AA/3 means 1/3 in length.


A size is a thicker size.


An A/3 looks like a cylinder with almost equal height and diameter.


A rechargeable 1.2V should do the trick as when fully charged they are 1.4V and as they discharge they go down to 1.2V. Underheating is not a bad thing. See previous posts.


Ni-Mi types should be chosen as the Ni-Cd have Cadmium which has radioactive isotopes.


About 200mAh should be great.


For 15V, should ten LR1130 button size batteries in series (one next to the other) be used in a cylindrical pack?


Something on the lines of the little 12V garage remote control battery F-LR23A which contains 9 1.5V battery elements.















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