27.195 MHz RCRS Data Signal Returns - 1655 UTC 06 Nov 2026 [N1NTE SDR]

[R4002]

27195 kHz data stream - RCRS "Class C" CB radio.  Received via Rob's SDR receiver - N1NTE SDR on the MA/CT Border - N1NTE KiwiSDR1. 

Frequency:  27.195 MHz FM. 

MFSK signal, bandwidth 4.5 kHz - signal appears to be slightly off-frequency (center frequency right around 27194.6 kHz or 27194.7 kHz).  This if still well within the FCC regulations for frequency stability per Part 95 of the FCC rules.  Bandwidth limit is 8 kHz.

Pretty noticeable fading / QSB. 

I did manage to capture a quick video clip from roughly 1658 UTC to 1659 UTC or so.  At 1700 UTC, AM voice signals coming out of "Carolina" started jumping in, also heard mention of "Mexico" - likely referring to the Mexican taxi cab dispatcher that also uses this same frequency.

Video clip:  https://youtu.be/ApFUSYxxF9g

EDIT:

47 CFR Part 95 Subpart C - RCRS

95.765 RCRS frequency accuracy. https://www.ecfr.gov/current/title-47/section-95.765

(a) Each RCRS transmitter type capable of transmitting on channels in the 72 or 75 MHz frequency band must be designed such that the carrier frequencies remain within ±20 parts-per-million (ppm) of the channel center frequencies listed in § 95.763(b) and (c) during normal operating conditions.

(b) Except as allowed under paragraph (c) of this section, each RCRS transmitter type capable of transmitting in the 26-28 MHz frequency band must be designed such that the carrier frequencies remain within ±50 ppm of the channel center frequencies listed in § 95.763(a) during normal operating conditions.

(c) Each RCRS transmitter type that transmits in the 26-28 MHz frequency band with a mean transmitter power of 2.5 W or less and is used solely by the operator to turn on and/or off a device at a remote location, other than a device used solely to attract attention, must be designed such that the carrier frequencies remain within ±100 ppm of the channel center frequencies listed in § 95.763(a) during normal operating conditions.


Presuming that the transmitter on 27.195 is operating under 47 C.F.R. 95.765(b), and if I am doing my math correctly:

50ppm frequency accuracy means +/- 1.35 kHz from the center frequency (so, in other words, the center frequency must fall within the range 27193.65 kHz to 27196.35 kHz).  Given that the signal seemed to be centered on 27194.6 kHz...well, that is very well within the legal range, even if we round up and make it 27193.7 kHz to 27196.3 kHz as the acceptable range. 

26993.7 kHz - 26996.3 kHz
27043.7 kHz - 27046.3 kHz
27093.7 kHz - 27096.3 kHz
27143.7 kHz - 27146.3 kHz
27193.7 kHz - 27196.3 kHz
27253.7 kHz - 27256.3 kHz

If the transmitter is operating under 47 C.F.R. 95.765(c), then the looser 100ppm frequency stability / frequency accuracy requirement...so +/- 2.7 kHz from center frequency (!!!) or


26992.3 kHz - 26997.7 kHz for 26.995 MHz
27042.3 kHz - 27047.7 kHz for 27.045 MHz
27092.3 kHz - 27097.7 kHz for 27.095 MHz
27142.3 kHz - 27147.7 kHz for 27.145 MHz
27192.3 kHz - 27197.7 kHz for 27.195 MHz
27252.3 kHz - 27257.7 kHz for 27.255 MHz