Allen H. Wood, Jr.'s amateur radio station callsign was 1DF.
 
QST, February, 1920, pages 44-45:

    Do you New England amateurs hear the wireless phone on 200 meters? Mr. A. H. Wood, Jr., of Winchester, is sending out music to the boys on one loaned by the Atlantic Radio Co. Bring in the Queen and let her hear it. Concerts Sunday at 3 p.m., also weekday evenings. The set has a range of about 100 miles and Mr. Wood would like to hear from amateurs outside of Massachusetts who hear it.