The Yaesu FRDX-400 is an amateur band receiver covering 1.7-2.3, 3.5-4.1, 6.9-7.5, 13.9-14.5, 20.9-21.5, 27.9-28.5, 28.5-29.1 MHz in AM, SSB and CW modes (FM mode is optional). This double conversion, tube receiver features mechanical filters, crystal controlled oscillators and crystal calibrator (25/100 kHz). It is designed to match the FLdx400 (FL-DX-SSB) transmitter. Mine is "loaded" with the FM detector and 6 and 2 meter converters and both wide AM and narrow CW filters. Features include a 1 kHz accurate analog dial, attenuator, crystal calibrator, noise blanker, AGC OFF/SLOW/FAST, RF gain and squelch. 14.5 x 6.5 x 11.5 inches 25 Lbs.
The Yaesu Musen FLDX-400 transmitter is capable of operating on all standard amateur frequencies between 3.5 and 30 mHz. It can generate CW, AM or SSB signals, with a peak power of 180 watts, and an average power of 120 watts using a pair of 6JS6 sweep tubes in the PA. Transceives with the FRDX400 or separate frequency control and provides dual receive, semi-break-in CW and VOX on transmit, and a frequency check spot switch.
Both units have built-in power supplies and were sold from about 1971 through 1974.