Note
310B: QST, Apr 1947, p. 144.
310B-1: QST, Aug 1947, p. 144.
310B-3, QST Jun 1948, p. 2. $215.00
310C-2: QST, Aug 1947, p. 144.
310C: QST, Jan 1948, p. 160. General specs.
QST, Sep 1948, p. 2. (General info and a few details on all)
Collins created the 31OB-3 by adding a universal antenna coupler to the 310B-1 's output circuit. The rigs are otherwise-identical, self-contained 15 watt exciters with band-switching 6AG7 buffer/multiplier stages, and a plug-in coil 2E26 final.