Note
QST, Nov 1954, p. 89.
Allied Radio catalog 1956 (copyright 1955), p. 200.
QST, Jul 1956, p. 95. (51SB-B)
Walter Ashe catalog 1957 (probably issued in 1956), p. 3. (version for other transmitters)
Allied Radio catalog 1959 (issued 1958), p. 379.
QST, May 1960, p. 152.
The 51SB-B was similar in function to the 51SB model but was made to work with the company's 5100-B transmitter. The newer version of the sideband adapter lacked an internal power supply and took plate and filament power from the 5100-B.
References
Brief technical description. Radio News, Oct 1955, p. 68.
Review. CQ, Feb 1959, p. 53.
