{"data":{"id":"us/47-cfr-80.209","jurisdiction":"us","citation":"47 CFR 80.209","heading":"Transmitter frequency tolerances.","body":"(a) The frequency tolerance requirements applicable to transmitters in the maritime services are shown in the following table. Tolerances are given as parts in 10 6 unless shown in Hz.\nFrequency bands and categories of stations Tolerances\n(1) Band 100-525 kHz:\n(i) Coast stations:\nFor single sideband emissions 20 Hz.\nFor transmitters with narrow-band direct printing and data emissions 10 Hz.1\nFor transmitters with digital selective calling emissions 10 Hz.\nFor all other emissions 100.\n(ii) Ship stations:\nFor transmitters with narrow-band direct printing and data emissions 20 Hz.\nFor transmitters with digital selective calling emissions 10 Hz.1\nFor all other transmitters 10 Hz.\n(iii) Ship stations for emergency only:\nFor all emissions 20 Hz.\n(iv) Survival craft stations:\nFor all emissions 20 Hz.\n(v) Radiodetermination stations:\nFor all emissions 100.\n(2) Band 1600-4000 kHz:\n(i) Coast stations and Alaska fixed stations:\nFor single sideband and facsimile 20 Hz.\nFor narrow-band direct printing and data emissions 10 Hz.1\nFor transmitters with digital selective calling emissions 10 Hz.1\nFor all other emissions 50 Hz.\n(ii) Ship stations:\nFor transmitters with narrow-band direct printing and data emissions 10 Hz.1\nFor transmitters with digital selective calling emissions 10 Hz.\nFor all other transmitters 20 Hz.\n(iii) Survival craft stations 20 Hz.\n(iv) Radiodetermination stations:\nWith power 200W or less 20.\nWith power above 200W 10.\n(3) Band 4000-27500 kHz:\n(i) Coast stations and Alaska fixed stations:\nFor single sideband and facsimile emissions 20 Hz.\nFor narrow-band direct printing and data emissions 10 Hz.1\nFor digital selective calling emissions 10 Hz.\nFor Morse telegraphy emissions 10.\nFor all other emissions 15 Hz.\n(ii) Ship stations:\nFor transmitters with narrow-band direct printing and data emissions 10 Hz.1\nFor transmitters with digital selective calling emissions 10 Hz.\nFor all other transmitters 20 Hz.\n(iii) Survival craft stations 50 Hz.\n(4) Band 72-76 MHz:\n(i) Fixed stations:\nOperating in the 72.0-73.0 and 75.4-76.0 MHz bands 5.\nOperating in the 73.74.6 MHz band 50.\n(5) Band 156-162 MHz:\n(i) Coast stations:\nFor carriers licensed to operate with a carrier power:\nBelow 3 watts 10.\n3 to 100 watts 5.3\n(ii) Ship stations 10.2\n(iii) Survival craft stations operating on 121.500 MHz 50.\n(iv) EPIRBs:\nOperating on 121.500 and 243.000 MHz 50.\nOperating on 156.750 and 156.800 MHz 10.\n(6) Band 216-220 MHz:\n(i) Coast stations:\nFor all emissions 5.\n(ii) Ship stations:\nFor all emissions 5.\n(7) Band 400-466 MHz:\n(i) EPIRBs operating on 406-406.1 MHz 5.\n(ii) On-board stations 5.\n(iii) Radiolocation and telecommand stations 5.\n(8) Band 1626.5-1646.5 MHz:\n(i) Ship earth stations 5.\n1 The frequency tolerance for narrow-band direct printing and data transmitters installed before January 2, 1992, is 15 Hz for coast stations and 20 Hz for ship stations. The frequency tolerance for narrow-band direct printing and data transmitters approved or installed after January 1, 1992, is 10 Hz.\n2 For transmitters in the radiolocation and associated telecommand service operating on 154.584 MHz, 159.480 MHz, 160.725 MHz and 160.785 MHz the frequency tolerance is 15 parts in 10.\n3 For transmitters operated at private coast stations with antenna heights less than 6 meters (20 feet) above ground and output power of 25 watts or less the frequency tolerance is 10 parts in 10.\n(b) When pulse modulation is used in land and ship radar stations operating in the bands above 2.4 GHz the frequency at which maximum emission occurs must be within the authorized bandwidth and must not be closer than 1.5/T MHz to the upper and lower limits of the authorized bandwidth where “T” is the pulse duration in microseconds. In the band 14.00-14.05 GHz the center frequency must not vary more than 10 MHz from 14.025 GHz.\n(c) For stations in the maritime radiodetermination service, other than ship radar stations, the authorized frequency tolerance will be specified on the license when it is not specified in this part.","path":["Title 47—Telecommunication","CHAPTER I—FEDERAL COMMUNICATIONS COMMISSION","SUBCHAPTER D—SAFETY AND SPECIAL RADIO SERVICES","PART 80—STATIONS IN THE MARITIME SERVICES","Subpart E—General Technical Standards"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-47.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:28Z","sha256":"a11a955f2845456d81f60d17aeffb2eea228c01f25bba4683908f28048530c79","source_id":"us-cfr","stale":true,"prev":"us/47-cfr-80.207","next":"us/47-cfr-80.211"},"notice":"GroundRules: Original legal text. Not legal advice."}