Signedplate on front, top: AMRAD / COUPLER MED.WAVE TYPE D-1. / American Radio and Research Corporation / NEW YORK, N.Y. MEDFORD HILLSIDE, MASS.
Historical AttributesCruft
Primary SourcesAMRAD, Amrad Receiving Units, Bulletin 5, February 1, 1921, p. 2. (See Radio Museum library.)
ProvenanceCruft Lab