Model 73
A - Spürgerät 73
Appareil de détection RA 73
Apparecchio didetezione RA 73
Model 73 Geiger Counter with rubber carry case.
Carry Case has belt loops on back.
This model has a built in speaker and a small neon light.
I do not know the ranges. There is a close up of the meter below.
Dimensions: 3" Wide x 6½" Long x 1½" Deep
Serial Number: 8008 033423
ALN / NSA / NDE 6665-758-9900
Front View
The control knob has five positions.
Off / Battery Check / R/hr / mR/hr with sound / mR/hr without sound
Instructions on back of unit are in three languages.
Click the thumbnail image above to see a full size scan of the back.
The following is the translation from German by Daniel in Slovakia.
His website is here.
INSTRUCTIONS FOR USE
The six bottom screws can not be released
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A. Replacement of the battery
1. Change the switch to <<0>>
2. Get the battery-cover off:
By using force on the channelled surface, together with moving it up.
3. Take the old battery out, place a new one.
Keep care on the polarity (the symbol + and -)
4. Place the battery-cover back:
By using force on the channelled surface, together with inserting it.
B. Measuring the intensity of radiation
1. Change the switch to <<BAT>> If the meter hand
is not in the black zone: Replace the battery
2. Change the switch to <<R/hr>>. If there is not deviation, change the switch to
<<mR/hr XXX>>. No deviation means no radioactivity.
3. When the intensity of the radiation is higher than 10 mR/hr a whistle tone resounds.
4. After use: Change the switch to <<0>>
C. For storing: Take the battery out.
There was a german word Ausschlag I translated it as ,,deviation".
I mean, that the meter hand has to move.
The XXX mark means the picture that shows a siren.
Thank You, Daniel
Inside View
There appears to be two Geiger-Müller tubes in the gray foam at the top.
View of Controls and Meter
Battery Compartment
This unit uses a battery pack, of the type shown on the right. These are common in Europe,
I'm told, but not here in the United States. Again, thanks to Daniel (see above) for this information.
See my solution below.
The alternative to European battery packs.
Radio Shack ® parts needed:
Part Number: 270-412 / 3 "AAA" Battery Holder
Part Number: 270-378 / Fully Insulated Mini 1¼' Alligator Clips
Part Number: 23-820 / AAA - Batteries Pack Of Four
Total Cost: About $10.00
Put color coded clips on the leads from the battery holder, solder on and connect to the proper terminals
in the battery compartment. Positive is on the left and Negative is on the right. I placed a small amount of
thin foam around the holder to keep tight in place. This setup works and the cover can be replaced.
No damage is done to the meter by using this battery pack substitute.
Model and Serial Number Nameplate