Getting Your satellite tv On A Break
TVRO systems were designed to receive analog and digital satellite feeds of both television or audio from both C-band and Ku-band transponders on FSS -type satellites.
36 Consequently, TVRO is often referred to as “big dish” or “Big Ugly Dish” (BUD) satellite television. 35 Early satellite television receiver systems were largely constructed by hobbyists and engineers. This was the primary method of satellite television transmissions before the satellite television industry shifted, with the launch of higher powered DBS satellites in the early 1990s which transmitted their signals on the Ku band frequencies.
Germany is likely the leader in free-to-air with approximately 250 digital channels (including 83 HDTV channels and various regional channels) broadcast from the Astra 19.2Â°E satellite constellation. 26 With pay television services, the datastream is encrypted and requires proprietary reception equipment. An event called sun outage occurs when the sun lines up directly behind the satellite in the field of view of the receiving satellite dish.
24 To decrypt the signal the receiver box must be “activated” by the satellite company. 20 This problem becomes more complicated when several receivers use several dishes or several LNBs mounted in a single dish are aimed at different satellites. 20 If several satellite receivers are to be attached to a single dish a so-called multiswitch must be used in conjunction with a special type of LNB.
The reason for using the LNB to do the frequency translation at the dish is so that the signal can be carried into the residence using cheap coaxial cable To transport the signal into the house at its original Ku band microwave frequency would require an expensive waveguide , a metal pipe to carry the radio waves. 22 The LNB amplifies the weak signals, filters the block of frequencies in which the satellite television signals are transmitted, and converts the block of frequencies to a lower frequency range in the L-band range. The downlinked satellite signal, weaker after traveling the great distance (see inverse-square law ), is collected by using a rooftop parabolic receiving dish (” satellite dish “), which reflects the weak signal to the dish’s focal point.
21 The uplink dish is pointed toward a specific satellite and the uplinked signals are transmitted within a specific frequency range, so as to be received by one of the transponders tuned to that frequency range aboard that satellite. 21 Uplink facilities transmit the signal to the satellite over a narrow beam of microwaves , typically in the C-band frequency range due to its resistance to rain fade 21 Uplink satellite dishes are very large, often as much as 9 to 12 metres (30 to 40 feet) in diameter 21 to achieve accurate aiming and increased signal strength at the satellite, to improve reliability. 20 This problem becomes more complicated when several receivers are to use several dishes (or several LNBs mounted in a single dish) pointing to different satellites.
20 If several satellite receivers are to be attached to a single dish, a so-called multiswitch will have to be used in conjunction with a special type of LNB. Newer LNBFs in use by DirecTV, called SWM (Single Wire Multiswitch), are used to implement single cable distribution and use a wider frequency range of 2-2150Â MHz. 15 The amplified signal, still at the higher microwave frequencies, had to be fed via very expensive low-loss 50-ohm impedance gas filled hardline coaxial cable with relatively complex N-connectors to an indoor receiver or, in other designs, a downconverter (a mixer and a voltage-tuned oscillator with some filter circuitry) for downconversion to an intermediate frequency.
The original C-band satellite television systems used a low-noise amplifier (LNA) connected to the feedhorn at the focal point of the dish. 11 The downlink satellite signal, quite weak after traveling the great distance (see inverse-square law ), is collected with a parabolic receiving dish, which reflects the weak signal to the dish’s focal point. 5 The uplink dish is pointed toward a specific satellite and the uplinked signals are transmitted within a specific frequency range, so as to be received by one of the transponders tuned to that frequency range aboard that satellite.
Thus the satellite dish antenna which receives the signal can be aimed permanently at the location of the satellite, and does not have to track a moving satellite.