Science: Tank Phones

The efficiency of a radio telephone, evolved by Captain K. E. Hartley of the British Territorial Forces, for use in army tanks, was exhibited last week on Salisbury Plain, England. Any member of a tank crew could operate it. Fine tuning had been eliminated by employing low frequency waves and a powerful, seven-tube superheterodyne receiver. Padded headphones protected the listener from internal and external din. The aerial, a hollow aluminum rod ten feet high, was equipped with a spring hinge to let it fold on the tank roof going under trees or bridges,...

Want the full story?

Subscribe Now

Subscribe
Subscribe

Get TIME the way you want it

  • One Week Digital Pass — $4.99
  • Monthly Pay-As-You-Go DIGITAL ACCESS$2.99
  • One Year ALL ACCESSJust $30!   Best Deal!
    Print Magazine + Digital Edition + Subscriber-only Content on TIME.com

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!