Note
QST, May 1972, p. 151.
Two versions available. One for Colllins KWM-2, 32S-1, and 32S-3, and a second for the Heath SB and HW series transceivers.
By August 1972 versions for many other brands and models were announced. QST, Aug 1972, p. 119.
Specific models and some specs listed: QST, Sep 1973, p. 135.
QST, Oct 1973, p. 136. (some discussion of how it works)
QST, Jan 1974, p. 158.
QST, Jul 1975, p. 171.
