Note
CQ, Nov 1958, p. 146.
QST, Jan 1959, p. 163.
H308 - without spower supply
H308A - with self-contained power supply
QST, Mar 1960, p. 144. "new designed and completely re-engineered."
References
Review (updated version): QST, Aug 1960, p. 44.
Review (updated version): CQ, Jan 1961, p. 58.