GPR-90 - Technical Material Corporation (TMC) communications receiver. The GPR-90 was manufactured between 1955 and 1960. This is one of the earlier versions without the crystal calibrator. This is a double conversion super heterodyne 15 tube general coverage communications receiver that covers 540 kHz through 31 mHz.
GSB-1 is a filter type adapter designed for use with receivers having a 455Kc IF. This unit matches the TMC GPR-90 receiver. The GSB-1 makes it very easy to tune SSB signals and is also useful when tuning AM & CW signals. Unit has a product detector which follows the band pass filter circuit. This is built to Mil JAN specs and is a rather rare TMC item.
TMC SBE-2 Transmitter Exciter. Covers 2-32 mc USB & LSB. Width 19", depth 16", height 9". Weight 26 lbs.
Frequency Shift Exciter XFK Receiver-Transmitter. Output freq. range is 1-6.9 mc. Freq. shift is linear to 1000 cps, output up to 3 watts, up to 1000 wpm keying speed. 115-270 volt @50-60 cps. Width 19", depth 15", height 10-1/2", weight 46 lbs.