Battery equivalents

[Yorkie]

does anyone know the equivalents for the following batteries
TR-233R and
RM-3 which is the old hearing aid battery.

they are for an Advance VM 78 millivoltmeter.

cheers Mark

The RM-3 was a Mallory 1.4V mercury cell used in valve hearing aids for the LT supply, but due to the high mercury content has long since ceased production, so the only solution would be to use a silver oxide 1.55V cell, which 'smallbatt' will doubtless sell, and you'll perhaps need to make a small adaptor so that it conforms to the dimensions of the RM-3. You may find the link below of interest, at the 'Hearing Aid Museum', (of all places!), concerning the RM-3:

http://www.hearingaidmuseum.com/gallery/...oryrm3.htm

(Maybe something like a CR2032 cell would suffice, but it will have a lower voltage than 1.4V)

Hope that helps a bit Mark.

David