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Here are two vintage cardboard OHM's Law and Reactance Slide Rules, designed for 1940s radio/TV /sound production.

OHMITE OHM's Law Calculator "Solves any OHM's Law problem with one setting of the slide" Up to 1000 OHMS. Dated 1940 Perry Graf Corp. Cardboard with metal rivets.
9-1/8" x 4-1/4" Nice condition. Only mild age-toning and scuffing.

SHURE BROTHERS Reactance Slide Rule for calculation of resonant frequency problems. Cardboard with metal rivets. 8-3/4" x 3-1/2". Good condition with mild scuffing.

These come with what may have been their original shipping envelope from Radio & Electronic Engineering Edition of Radio and Television News. Also, a four page pamphlet called "How to Use the Radio & Television News Calculator.

Please consult all photos.

These ship USPS First Class from beautiful Portland, Oregon.

1940s OHMITE OHM's Law Calculator and Shure Brothers Reactance slide rules, brochure. Radio. Television. Broadcast history. Vintage tech.


Only 1 available


  • Vintage item from the 1940s
  • Only ships within United States.
  • Feedback: 267 reviews
  • Favorited by: 4 people