QST, May 1961 inside front cover.
Allied Radio catalog 1962 (copyright 1961), p. 273.
QST, Jun 1964, p. 157.
QST, Aug 1965, p. 160. (Out of production in the summer of 1965. Harrison bought out all remaining stock, and the unit was available for purchase through at least May 1966)
Requires the P-26 power supply.
HA-2 discontinued after 1964?
