In the early seventies, Drake's first solid state communications receiver SPR-4 with crystal controlled coverage of the international shortwave broadcast bands has been a dream of many shortwave listeners.
The RR-1 has been a variant of this receiver intended for professional use as maritime tixed or mobile reserve receiver. Crystals for the maritime bands have been provided, there has been the possibility to buy optional crystals for up to four additional 500 kHz segments. With the external oscillator FS-4, continuous coverage with switchable 500 kHz segments up to 30 MHz has been available.

My RR-1 receiver, I got this one from DL1SDQ, has been sold by the German maritime communications equipment company DEBEG under the DEBEG 7220 designation with german language lettering on it's front panel. The dimensions of the grey metal tabletop cabinet are 51 x 21 x 30 cm. In the left half of the front panel, You find all the controls as found on a regular SPR-4, in the right half, You find an internal monitor speaker and a few controls typically used for onboard operation on vessels.

In the top section of the left half of the RR-1's front panel, You find the signal strength meter calibrated in S units, the band segment switch and the main tuning dial, all backlit in Drakes' typical bright blue colour.
The band selector is the small knob underneath the middle window, a yellowish illuminated sector will indicate the start frequency of the selected 500 kHz band segment, a number will indicate the recommended position of the preselector and a letter the respective BAND RANGE switch setting.
The main tuning knob below the frequency dial indicating the frequency with an accuracy of better then 1 kHz is placed virtually in the center of the front panel.
In the row of knobs below the preselector control, You will find the BAND RANGE switch (Bereich) with it's letters leftmost, the headphones jack and then two concentric knobs for RF gain and AF gain (volume), this one will also act as mains switch.
The reception mode switch has positions for AM reception (A2 / A3), for narrow CW reception (A1) and for LSB (A1 broad) / USB reception. An additional knob at the right hand below the main tuning knob sets the receiver in normal receiving mode, activates the crystal calibrator and the Noise Blanker mode, the inner of the concentric knobs controls the famous Drake RF Notch filter to eliminate interference from adjacent channel signals.

In the right part of the front panel, You find a few controls only available for this maritime communications variant and not found in the regular SPR-4: There is a row of switches to activate the internal monitor speaker, an additional 20 dB attenuator, the selector for mains / AC and ship battery / DC operation and for automatic or manual gain control.
At the right hand below the speaker grille, You find the necessary fuses for AC and DC / ship battery operation, all accessible from the front panel.

At the rear of the set, You find only an antenna connector and a muting connector, this will mute the receiver to protect the receiver front end from strong signals when a nearby onboard ship transmitter is in action.

The operation of the RR-1 is a bit typical for earlier Drake sets and not all straightforward. You switch the set on using the AF gain / volume ccontrol. Set the MODE switch to A2/A3 for regular AM reception. Now turn the Band Segment switch to select the appropriate 500 kHz segment, e.g. the 12 MHz segment. The number and the letter appearing in the window will indicate the recommended settings for the BAND RANGE switch (in this example the F) and the preselector, to continue with this example in the middle between the 6 and 7 marks.
To tune in to 12 0 9 5 kHz, set the main dial to 95 and You might already hear something. Tweak the preselector control for maximum S meter reading and readability. After switching to A1 LSB or USB, You may retune with the main tuning knob to zero beat (this will mean until the hiss disappears and the voices sound natural and not like Mickey Mouse anymore) und select the upper or lower sideband for single sideband (ECSS) reception.

Shortwave performance is similar to the one found in Drake's SPR-4 receiver, You will find a good dynamic range and rejection of unwanted signals, but You will have to accept to select Band Range and adjust the preselector manually after changing frequencies every time. With these disadvantages and the selective coverage of maritime bands that are not longer used for these kind of communication, the RR-1 is regarded as a collector's item more then a contemporary DXing machine.