Multiplexutrustning TM-X11
(G.E.C. Five-circuit Carrier Telephone Equipment)
Tillverkare The General Electric Co.Ltd, Coventry, England
(Utdrag ur ”Beskrivning över 5-kanalutrustning” Juni 1953)
GENERAL DESCRIPTION
The G.E.C. Five Circuit Carrier Equipment provides 5 300-2800c/s speech circuits together with signalling facilities and is designed for operation over radio links.The five circuits are transmitted to, and received from, the radio equipment as one audio circuit plus four carrier circuits. The carrier circuits employ single sideband suppressed carrier system of transmission.
Two carrier frequencies are employed for modulating the circuits,·one 6.667kc/s serves circuits 2 and 3 while the other 13.333kc/s serves circuits 4 and 5. Both of these frequencies are derived from a common 100kc/s crystal controlled master oscillator. The total frequency band transmitted to and received from the radio equipment is 0.3 to 16.133kc/s. The following table shows the frequency band of each circuit.
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The speech circuits may·be extended on either a 2-wire or a 4-wire basis. Selection of either method is by the movement of the two multi-way plugs.
The equipment is continuously adjustable to cover a speech channel input range of -10 to 0dbm (-14 to +4dbm for 4-wire extensions). Continuous adjustment is also provided to cover a speech channel output range of -10 to 0dbm (-6 to +14dbm for 4 wire extensions).
The sideband level transmitted to the radio transmitter is -26dbm (per channel) and the sideband level (per channel) received from the radio receiver is 0dbm.
A 2280c/s tone is used to give voice frequency signalling facilities over the circuits. Convertors are provided at each end of the circuit to convert the 2280c/s tone to 17c/s ringing and vice versa. The convertors may also be used for DC signalling, if this is required.
The equipment is built up of eight panels mounted in a folded steel framework. The panels slide into guides fitted on the inside edges of the rack. Covers are provided for each panel and these are secured by self-locking fasteners. Electrical connexions between the rack wiring and the panels are made by means of multi-way plug-in links fitted between sockets, one set being mounted at each end of the panel, and the other sets on the panel guides.
All external connexions other than the power supply are made to terminal strips mounted at the top of the rack.
Bilder
Meter-utr. för 5 talkanaler (FM-radioutr. med bärfrekvens). Antenn för metervåg.
Dokument
Se under Telekommunikation FFRL/FTN eller under Dokument.