Note
QST, Aug 1957, p. 1.
QST, May 1959, p. 107. (some technical notes)
QST, Sep 1959, p. 101. ("where is the FPM-200?")
QST, Apr 1960, p. 87. (notes on)
The finished product would not be announced until May, 1959, but would not be offered for sale until Oct 1961.