Note
QST, Mar 1948, inside back cover.
See National's Notes: QST, Jun 1949, p. 73.
Lafayette-Concord (1949 #949), p. 144.
Allied Radio catalog 1951 (copyright 1950), p. 140.
QST, Sep 1951, p. 117. ("while they last")
QST, Jan 1952, p. 109. (available as NOS?).
QST, Aug 1952, p. 111.
The NC-33 used six tubes and tuned from 0.50–35 MHz in four bands. Its main-tuning dial was calibrated, and the band-spread dial carried a numerical logging scale.