Magnetostrictive Ultrasonic Delay Lines for a PCM Communication System

A servo-operated delay-line pad and a temperature-compensated delay-line memory, both magnetostrictively driven at 1.5 mc, have been used in an experimental PCM communication system.1 The delay-line pad automatically compensates for external delay changes as small as plus or minus 8 mμsec at a rate of 75 mμsec second. The delay-line memory stores 192 bits which are available serially with an access time of 125 μsec. Both applications use the same basic delay lines which consist of a length of 0.003-inch diameter supermendur wire, two tiny solenoids, and a supporting structure.