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An SSTV repeater is an amateur radio repeater station that relays slow-scan television signals. A typical SSTV repeater is equipped with a HF or VHF transceiver and a computer with a sound card, which serves as a demodulator/modulator of SSTV signals. SSTV repeaters are used by amateur radio operators for exchanging pictures.
In the mid-1960s, Simplex attempted to introduce low-voltage DC systems; these panels were not a success. Most of Simplex's audible notification appliances prior to the 1990s were relabeled Benjamin Electric, Federal Signal, Faraday, and Autocall devices. Simplex's time-division began to lose market share, but their newly founded fire alarm ...
From 29.000 MHz to 29.700, The FM sub-band is usually channelized into repeater and simplex frequencies. The channels are commonly grouped into repeater inputs, simplex, and repeater output frequencies. Repeater input frequencies: 29.510, 29.520, 29.530, 29.540, 29.550, 29.560, 29.570, 29.580 and 29.590 MHz.
Coded panels were the earliest type of central fire alarm control, and were made during the 1800s to the 1970s. A coded panel is similar in many ways to a modern conventional panel (described below), except each zone was connected to its own code wheel, which, depending on the way the panel was set up, would either do sets of four rounds of code until the initiating pull station was reset ...
UHF CB is a class-licensed citizen's band radio service authorised by the governments of Australia, Europe, Malaysia, New Zealand, Singapore, Vanuatu, and in the PMR446, UHF 477 MHz band. [1]
To avoid interference within the equipment at the station, the two frequencies used need to be separated, and ideally on different 'bands'. An unattended station working in this way is a radio repeater. It re-transmits the same information that it receives. This principle is used by telecommunications satellites and terrestrial mobile radio ...
Motorola TA288 PMR446 licence-free radio Motorola TLKR T40 radio tuned to PMR channel 1. PMR446 (Private Mobile Radio, 446 MHz) is a licence-exempt service or UHF CB in the UHF radio frequency band, as personal radio service or citizens band radio, and is available for business and personal use in most countries throughout the European Union, [1] Malaysia, [2] Singapore, [3] Norway, [4] and ...
This feature is common in European systems. In a simplex system, the 5-tone just opens the speaker of the desired partner. In a repeater system, another CTCSS or tone-burst or 5-tone is needed to activate the company's repeater, depending on the systems design. If the called radio is within reach of the sender, it answers the incoming call with ...