Seventy-five years ago this month, the May 1942 issue of Radio Craft featured on its cover this handheld radio telephone weighing only four pounds, which the magazine noted was not much larger than the handset of a “French” telephone. The set was the product of the Weltronic Corporation, which was the assignee of the patent, U.S. Patent 2276933, with a pre-Pearl Harbor application date of October 1, 1941, and an issue date of March 17, 1942.

The magazine noted that the set had a range of about a mile, and could operate on any frequency between 112-300 MHz. The diagram below reveals that the set appears to be one tube functioning as an oscillator and superregenerative detector, with the other tube serving as AF amplifier to drive the headphone on receiver, and as modulator on transmit.

Commercially available batteries were said to allow continuous operation for eight hours, or about a week to a month in normal service. The article noted that the set was being made available to governmental agencies.

The cover photo shows the unit in use by a guard around a defense plant.

The article puts quotation marks around the word “transceiver,” since such a combined unit would have been unfamiliar to many readers.