Tag "intercom"
Selsyn-Powered Intercom (Jul, 1947)

Selsyn-Powered Intercom

Spells Out Messages

SOME of those mysterious little gadgets that made certain war equipment seem almost like magic are finding their way to the sales counters as surplus goods. One of them is the selsyn, that onetime highly secret device used in antiaircraft weapons, bomb sights, and radar. Selsyns in small sizes can be picked up in dozens of stores now for between $3 and $5, and many of them will operate on ordinary 115-volt A.C.