This data is courtesy of Jon Pevner. The same table in the SRR-series manual lists only the SRR-11, 12, and 13/13A receivers. TABLE 1-4. BASIC SIMILARITIES OF RADIO RECEIVING SETS AN/FRR, AN/MRR, AND AN/SRR Ref: NAVSHIPS Tech Manual 92211, AN/FRR-21, -22, -23 (edited for brevity) MODEL FREQUENCY EMISSION POWER MECHANICAL REMARKS COVERAGE TYPES SOURCE DESIGN ========================================================================================= FRR-18 16-600 KHz A1 A2 F1 105/15/25 Metal Case Shore LF FSK service. 50-60 Hz Rack Mounted Crystal local osc. or 400 Hz ----------------------------------------------------------------------------------------- FRR-19 2-32 MHz A1 A2 A3 " " Shore HF FSK service. F1 Crystal local osc. ----------------------------------------------------------------------------------------- FRR-21 16-600 KHz A1 A2 A3 " " Shore LF communications. F1 ----------------------------------------------------------------------------------------- FRR-22 .25-8 MHz A1 A2 A3 " " Shore MF communications. F1 ----------------------------------------------------------------------------------------- FRR-23 2-32 MHz A1 A2 A3 " " Shore HF communications. F1 ----------------------------------------------------------------------------------------- MRR-1 16-600 KHz A1 A2 F1 " Waterproof Mobile/Transportable LF Case, portable ----------------------------------------------------------------------------------------- MRR-2 .25-8 MHz A1 A2 A3 24 VDC* " Mobile/Transportable MF F1 105/15/25 VAC 50-60 Hz or 400 Hz ----------------------------------------------------------------------------------------- MRR-3 2-32 MHz A1 A2 A3 " " Mobile/Transportable HF F1 ----------------------------------------------------------------------------------------- SRR-11 16-600 KHz A1 A2 F1 105/15/25 Metal Case, Shipboard LF 50-60 Hz Table-top communications ----------------------------------------------------------------------------------------- SRR-12 .25-8 MHz A1 A2 A3 " " Shipboard MF F1 communications ----------------------------------------------------------------------------------------- SRR-13/ 2-32 MHz A1 A2 A3 " " Shipboard HF SRR-13A F1 communications ----------------------------------------------------------------------------------------- *Separate power supply assembly required for 24 VDC operation