This 19 inch rack model marine receiver DRAKE RR-1 was produced between 1971-1977 in USA and it is based on the same concept as the DRAKE SPR-4.
The market was oceangoing vessels and it contains complete coverage for maritime communications from 150 kHz to 30 MHz. Intermediate frequency is 5645 kHz and 50 kHz and the bandwidth can be set from
0,4 kHz to 4,8 kHz. As with the DRAKE SPR-4 it’s a receiver built on solid state devices, containing dual gate MOS-FET transistors that gives very low intermodulation, high dynamic range and overload performance. After setting the crystal selector switch (band determining crystals) to one of 24 frequency bands, selection of band range (one of 8, A to H) and adjustment of the preselector has to be done. Each band segment is 500 kHz wide. The audio output is 3 watts and it’s powered by 120/230 VAC 50-60 Hz 18 watts or from 24 VDC 6 watts.
My item receives on AM, CW, LSB, USB modes and have a 100 kHz crystal calibrator and a NoiceBlanker installed. Dimensions are (W*H*D) 483*178*333 mm (19*7*13.1 inch) and without rack it weights 6,7 kg (14.77 lbs).
Now this receiver has been sold (february 2018) to a radioamateur 18 km northwest of Stockholm. He now have a complete collection of professional receivers from Drake!