Note
QST, May 1961, p. 105.
CQ, Sep 1969, p. 41.
QST, Apr 1973, p. 116.
Mark II
unknown
Mark III
QST, Nov 1968, p. 5.
Mark IV
QST, Jan 1970, p. 5.
QST, Sep 1970, p. 137.
Unsure if #3340 refers to all models.
References
Review: QST, Feb 1962, p. 51.
Brief description (Mk IV). Ham Radio, Feb 1970, p. 76.