Note
QST, Mar 1968, p. 125.
QST, Sep 1968, p. 141. (a few details)
QST, Jan 1971, p. 5.
The Henry 2K-3 changed the amplifiertubes to a pair of Eimac 3-500Zs. The new tubes produced greater output with less drive than the 3-400Zs used in the 2K-2 amplifier.