{"data":{"id":"us/47-cfr-90.221","jurisdiction":"us","citation":"47 CFR 90.221","heading":"Adjacent channel power limits.","body":"(a) For the frequency bands indicated below, operations using equipment designed to operate with a 25 kHz channel bandwidth may be authorized up to a 22 kHz bandwidth if the equipment meets the adjacent channel power (ACP) limits below. The table specifies a value for the ACP as a function of the displacement from the channel center frequency and a measurement bandwidth of 18 kHz.\n(b)(1) Maximum adjacent power levels for frequencies in the 450-470 MHz band:\nFrequency offset Maximum ACP (dBc) for devices 1 watt and less Maximum ACP (dBc) for devices above 1 watt\n25 kHz −55 dBc −60 dBc\n50 kHz −70 dBc −70 dBc\n75 kHz −70 dBc −70 dBc\n(2) In any case, no requirement in excess of −36 dBm shall apply.\n(c)(1) Maximum adjacent power levels for frequencies in the 809-824/854-869 MHz band:\nFrequency offset Maximum ACP (dBc) for devices less than 15 watts Maximum ACP (dBc) for devices 15 watts and above\n25 kHz −55 dBc −55 dBc\n50 kHz −65 dBc −65 dBc\n75 kHz −65 dBc −70 dBc\n(2) In any case, no requirement in excess of −36 dBm shall apply.\n(d) On any frequency removed from the assigned frequency by more than 75 kHz, the attenuation of any emission must be at least 43 + 10 log (Pwatts) dB.","path":["Title 47—Telecommunication","CHAPTER I—FEDERAL COMMUNICATIONS COMMISSION","SUBCHAPTER D—SAFETY AND SPECIAL RADIO SERVICES","PART 90—PRIVATE LAND MOBILE RADIO SERVICES","Subpart I—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":"bdfcd01f37ce658e1e209c552155548a1035efe51babf0167252e67fcc8b40a4","source_id":"us-cfr","stale":true,"prev":"us/47-cfr-90.219","next":"us/47-cfr-90.223"},"notice":"GroundRules: Original legal text. Not legal advice."}