Note
CQ, Jun 1964, p. 9.
QST, Jan 1965, p. 99.
QST, Feb 1965, p. 133. (full specs)
QST, Dec 1965, p. 139. (R-4A)
Drake's R-4 receiver tuned fifteen 500 kHz ranges between 1.5-30 MHz (with the exception of 5 to 6 MHz) and was supplied with crystals for 80, 40, 20, 15 meters, and 28.5-29 MHz on 10 meters. The crystal switch had 1 0 spare positions for optional crystals. Its linear PTO had 1 kHz dial divisions. The double-conversion receiver had a first IF at 5645 kHz with a crystal lattice filter and a 50 kHz 2nd IF with UC filtering. Its passband tuning offered bandwidths of 0.4, 1.2, 2.4, and 4.8 kHz. The R-4 used 13 tubes and 7 diodes. It had a noise blanker, notch filter, and crystal calibrator.
The Drake R-4A was similar in concept and appearance to the R-4, with some internal circuit changes, including a solid-state PTO. It was manufactured in both 11 and 13 tube versions.
The series continued with the R-4B and R-4C. See separate entries for each.
