The IM-179 is a really neat little meter unless you need to measure background,
but there are other meters for that. I've been using the following as replacement
batteries for my IM-179:
#1 [Replacement for Mallory BA1312U]:
Batteries Plus: ALK 1.5V/325Mah Cat # DURPC640A Were $2.99 each
UPS #041333040431 Batteries Plus -91
On the battery it says:
PC640A China (Ha!) Alkaline
#2 [Replacement for Mallory BA1318U]: Batteries Plus DANTR164A Batteries Plus #90 Were $11.99 each
On the battery is says:
Excell A32 . A164 6.0V Alkaline
PX32A EN164A PC164A
Hope this helps. Isn't it amazing how common pieces of equipment from divergent sources show up in the hands of people who read this publication. :-) Best Regards, - The Army Aviator
I have several the original [IM 179] units. Batteries are no longer manufactured. But Major Surplus has the replacements for about $19.00 plus shipping. Great little meters. The calibration is off a little and when you test the meter swings over too far. After test you must let meter reset for 10 minutes to clear the ion tube. You will have to make an adapter for the 640A cell that replaces the large round mercury cell. You can make one out of thick cardboard or fiberboard. The Units purchased from Major Surplus come with the adapter. Major has the Duracell PX32A, made for them buy Excell. Jordan Electronics in California calibrated them for Major and work great. The reason for the change was because the big cell was mercury. Best of luck. - JWH
The IM 179 is a nice little radiac set that it easy to use and handy but the batteries have been out of production for a long time. The good news is that commercial batteries can be adapted for it.
The information is in the book "Power up" that I wrote about 13 years ago. It has been out of print for several years and the publisher is out of business. About a year ago I found that the book could be downloaded from a web site in the UK called "Army Radio". As I recall this site is for collectors of military radios.
The adapter for the IM 179 used one Duracell PX32 & one Duracell R640. A little cardboard , masking tape & aluminum foil & you are in business. Note: You MUST watch the polarity as the suggested batteries have a "negative tip"!
BTW, the PX32 can also be used in an adapter for the old "Firefly" strobe. At the time I wrote the book these were available at most Radio Shack stores but I do not know it this it still true. I hope this helps & if needed I can try to sent you the plans for this to share with readers. - Dave