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The type of radio emission is “F1D”, frequency-shift keying. A message contains a station's callsign, Maidenhead grid locator, and transmitter power in dBm. [3] The WSPR protocol compresses the information in the message into 50 bits (binary digits).
Repeater frequency sets are known as "repeater pairs", and in the ham radio community most follow ad hoc standards for the difference between the two frequencies, commonly called the offset. In the USA two-meter band, the standard offset is 600 kHz (0.6 MHz), but sometimes unusual offsets, referred to as oddball splits, are used. The actual ...
IRLP connections are of two types: node to node, and node to reflector. Stations wishing to communicate with 3 or more nodes at the same time may accomplish this by connecting to what is called an IRLP Reflector. Reflectors are a type of conferencing system. Most reflectors on the network have 10 channels (0–9) with channel 0 being the main ...
M17 uses Frequency-Division Multiple Access (FDMA) technology in which different communication streams are separated by frequency and run concurrently. It utilizes 4,800 symbols per second, 4-level frequency-shift keying (4FSK) with a root Nyquist filter applied to the bitstream. Radio channels are 9 kHz wide, with channel spacing of 12.5 kHz.
The current master gateway in the United States is operated by the K5TIT group in Texas, who were the first to install a D-STAR repeater system in the U.S. [10] D-STAR transfers both voice and data via digital encoding over the 2 m (VHF), 70 cm (UHF), and 23 cm (1.3 GHz) amateur radio bands.
Automatic Packet Reporting System (APRS) is an amateur radio-based system for real time digital communications of information of immediate value in the local area. [1] Data can include object Global Positioning System (GPS) coordinates , non-directional beacon , weather station telemetry, text messages, announcements, queries, and other telemetry .
Repeater systems use two different radio frequencies; the mobiles transmit on one frequency, and the repeater station receives those transmission and transmits on a second frequency. Since the repeater must transmit at the same time as the signal is being received, and may even use the same antenna for both transmitting and receiving, frequency ...
MDC (Motorola Data Communications), also known as Stat-Alert, MDC-1200 and MDC-600, is a Motorola two-way radio low-speed data system using audio frequency shift keying, (AFSK). MDC-600 uses a 600 baud data rate. MDC-1200 uses a 1,200 baud data rate. Systems employ either one of the two baud rates.