The bandwidth is expressed as three digits and a letter that occupies the position normally used for a decimal point. The letter indicates what unit of frequency is used to express the bandwidth. H indicates Hertz, K indicates kilohertz, M indicates megahertz, and G indicates gigahertz. For instance, "500H" means 500 Hz, and "2M50" means 2.5 MHz.
| N | Unmodulated carrier |
| A | Double- sideband amplitude modulation (AM broadcast radio) |
| H | Single-sideband with full carrier (used by CHU) |
| R | Single-sideband with attenuated carrier |
| J | Single-sideband with no carrier ( Shortwave utility and amateur stations) |
| B | Two sidebands containing different signals |
| C | Vestigial sideband (e.g. NTSC) |
| F | Frequency modulation (FM broadcast radio) |
| G | Phase modulationPhase modulation (PM) is the encoding of information into a carrier wave by variation of its phase in accordance with an input signal. Note that phase modulation can be regarded as a special case of frequency modulation where the carrier frequency modulat |
| D | Combination of AM and FM or PM |
| P | Sequence of pulses without modulation |
| K | Pulse amplitude modulation |
| L | Pulse width modulation (used by WWVBWWVB is a special NIST time signal radio station in Fort Collins, Colorado, co-located with WWV. WWVB is the station that radio-controlled clocks throughout North America use to synchronize themselves. The signal transmitted from WWVB is a continuous 60 k) |
| M | Pulse position modulation |
| Q | Sequence of pulses, phase or frequency modulation within each pulse |
| V | Combination of pulse modulation methods |
| W | Combination of any of the above |
| X | None of the above |
| N | No transmitted information |
| A | Aural telegraphy ( Morse codeMorse code is a system of representing letters, numbers and punctuation marks by means of a code signal sent intermittently. It was developed by Samuel Morse and Alfred Vail in 1835. Morse code is an early form of digital communication; however, unlike mo) |
| B | Electronic telegraphy ( RadioteletypeRadioteletype RTTY is a telecommunications system consisting of two teleprinters linked by a radio link. RTTY uses a variety of different modulation methods, of which frequency shift keying are the most common. The coding used is the 5-bit ITA2 code (also and digital modes) |
| C | Facsimile (Still images) |
| D | TelemetryTelemetry is a technology which allows the remote measurement and reporting of information of interest to the system designer or operator. The word is derived from Greek roots tele remote, and metron to measure. Telemetry typically refers to wireless comm or Telecommand (Remote control) |
| E | Telephony (voice or audio signals) |
| F | Video ( television signals) |
| W | Combination of any of the above |
| X | None of the above |
