Note
QST, Jul 1955, inside back cover. "Coming soon!"
QST, Oct 1955, p. 160. "Available now" / specs.
QST, Nov 1955, inside back cover. (lots of detail)
Allied Radio catalog 1958 (copyright 1957), p. 266.
QST, Feb 1960, p. 141.
National's NC-300 was double-conversion with IFs at 2215 and 80 kHz. It had a crystal filter in the 1st IF. It covered the 160–10 meter bands and had a band at 30–35 MHz that served as a tunable IF for VHF converters. It was calibrated for 6, 2, and 1-1/4 meters. The 13-tube NC-300 had a product detector, and its AVC could be used on CW and SSB.
References
Technical description. Radio News, Oct 1955, p. 96.
Adding WWV. CQ, Feb 1959, p. 39.
Revisions. CQ, May 1959, p. 41.
