|The Drake SPR-4
receiver is an all solid-state communications receiver (Drake's first completely
solid-state receiver) which can be programmed with accessory crystals to
cover 150 kHz to 30 MHz. The SPR-4 receives AM, CW, SSB (upper and
lower) and may be powered from 120 VAC, 240 VAC and 12 VDC. It can
be used for transceive with the T-4 or T-4XB/C with a TA-4 adapter. It
was manufactured from 1969 - 1978.