Note
QST, May 1963, p. 137.
QST, Jan 1964, p. 129.
Allied Radio catalog 1965 (copyright 1964), p. 322.
Drake's first transceiver used three 12BJ6 sweep tubes in its final amplifier to generate 300 watts PEP input. The TR-3 offered full coverage of 80-10 meters and featured linear PTO tuning. Although primarily designed for sideband operation, it could also be used on CW and controlled-carrier AM. A pair of 2.1 kHz crystal filters provided upper and lower sideband on transmit and receive. External power supplies were required for both mobile and fixed operation.