Note
QST, Apr 1948, inside back cover.
Allied Radio catalog 1953 (copyright 1952), p. 41.
The HFS covered 27-250 MHz using six sets of plug-in coils. It was a super-regenerative receiver that could also be used as a tunable VHF converter ahead of a communications receiver. An Internal/External switch connected the 10.7 MHz IF output to a separate receiver and disabled its own detector and audio stages. An external power supply was required.
References
National's Notes: QST, Apr 1948, p. 73.
National's Notes: QST, Oct 1951, p. 79.
