PROGRESS REPORT ON THE DESIGN AND CONSTRUCTION OF SIDE TONE DELAY APPARATUS ON SUBCONTRACT UNDER CONTRACT (DELETED).

/47/g 1-/x �3(2 - Progress Report on the Desirn and Construction of Side Tone i:lolay Apparatus on Subcontract under Contract The first apparatus built was dsisigned on the principle of a con- stant tape speed of about 40" per second with a variable distance between the recording and playback heads. The recording head was fixed in position and the playback head was movable on a track thich was designed to preserve the alignment. The tape in the form of on endless loop was carried over to light l...