gener-raco: Likely battery type for General Radio 174B
gener-raco: Likely battery type for General Radio 174B
Inside the wooden housing of the GR 174B wavemeter is a square bracket and spring contacts surrounding an obvious space for a battery. In the 1920's, the Eveready 771 "C" battery measured 4" wide, 3" tall and 1.3" deep. It exactly fits the space, and the 4.5 V is about right to drive the buzzer. The 771 was a very common battery back then, and I could find no other battery that even came close to the right size and voltage. Most 771 batteries came with Fahrensotck clip connectors, but I think there were versions with simple flat contacts. So, I think it is pretty obvious that the GR 174B used a 4.5V Eveready 771 battery. BTW it's very easy to 3D print or otherwise construct a box of the right size and stuff it with 3 or 6 modern C batteries.
Attachments:- Replica 771 in GR 174B housing (251 KB)
To thank the Author because you find the post helpful or well done.