A cryogenic receiver covering the 200-350 GHz range is described. Two Schottkydiode mixers cover this range, with the mixers and FET IF amplifier cooled to 20 K. LO power is provided by a frequency doubler/tripler, with a Martin-Puplett interferometer used as the LO-signal diplexer. The best system temperature is 710 K SSB at 225 GHz, rising to 2000 K at 348 GHz.