Big ugly dish

A C-Band Dish (often abbreviated to BUD or Big Ugly Dish) is a colloquial name for a TVRO satellite dish used to receive satellite television signals from FSS-type satellites on the microwave C band. BUDs are usually 6.5 to 12 feet in diameter and have been a source of much consternation (even local zoning disputes).

History

BUDs were originally marketed in the late 1970's, with the earliest dishes being made of solid fiberglass and later models being made of wire mesh and solid steel or aluminum. BUD systems of the time came at a high cost, usually several thousand dollars.

They work by receiving a low power C-Band (~5GHz) frequency modulated analogue television signal directly from the original distribution satellite-the same signal received by cable company headends. Because analogue channels took up an entire transponder on the satellite, and each satellite had a fixed number of transponders dishes were usually equipped with a polar mount and actuator to sweep the dish across the horizon to receive channels from multiple satellites. Switching between horizontal and vertical polarization was accomplished by a small electric servo motor which moved a probe inside the feedhorn throat at the command of the receiver (Commonly called a "polarotor" setup). Higher end receivers did this transparently, switching polarization and moving the dish automatically as the user changed channels.

Originally, all channels could be received free of charge. In 1986 HBO began using the (now obsolete) VideoCipher system to encrypt their channels. This met with much protest from owners of big dish systems, most of which had no other option at the time for receiving such channels. Eventually HBO allowed dish owners to subscribe directly to their service, although at a price much higher ($12.95/month) than what cable subscribers were paying. This led to the 1986 attack on HBO's transponder on Galaxy 1 by Captain Midnight. One by one, all commercial channels followed HBO's lead and began encrypting their channels. Analogue encryption using VideoCipher and VideoCipher II could be defeated, and there was a market for descramblers. In the mid-90s, channels began moving their broadcasts to digital transmission using DigiCipher, resulting in the rapid decline of the BUD era.

In addition to encryption, DBS services such as PrimeStar had been reducing the popularity for BUDs since the early 1990s. Signals from DBS satellites (operating in the K_u band) are higher in power and therefore require much smaller dishes than C band, and the digital signals now used require far less signal strength at the receiver resulting in a lower cost of entry. General advancements in noise abatement have also had an effect. As a consequence of this, BUD systems were virtually extinct by 2000.

Popularity

BUDs were most popular in rural areas. The mountainous terrain of West Virginia makes reception of over-the-air television broadcasts (especially in the higher frequencies) very difficult. From the 1970s to the early 1990s DBS systems weren't available and cable systems of the time only carried a few channels, resulting in a boom in sales of BUDs in the area which led to the systems being termed the "West Virginia State Flower". The term was regional, known mostly to those living in West Virginia and surrounding areas. Support for BUDs dried up when strong encryption was introduced around 1994. Many long disconnected BUDs still occupy their original spot. Due to the number of systems in existence, their lack of usefulness, and because many people consider them an eyesore, used BUDs can be purchased for very little money.

Current Uses

The free analouge channels that BUDs were built to receive are mostly a memory, as of 2008 there are only 13 English language channels left [ [http://www.lyngsat.com/america.html LyngSat North America] ] , leaving the receivers virtually useless. The dishes themselves can be modified to receive free to air and DBS signals. The stock LNBs fitted to typical BUDs will usually need to be replaced with one of a lower noise temperature to receive digital broadcasts. With a suitable replacement LNB (provided there's no warping of the reflector) a BUD can be used to receive free to air and DBS signals. Several companies market LNBs, LNBFs, and adaptor collars for big dish systems. For receiving FTA signals the replacement should capable of dual C/K_u reception with linear polarization, for DBS it will need a high band K_{u LNBF using circular polarization. Older mesh dishes with perforations larger than 5mm are inefficient at Ku frequencies. Solid fiberglass dishes usually contain metal mesh with large diameter perforations as a reflector and are usually unsuitable for anything other than C band.}

Large dishes have higher gain which can be an advantage when used with DBS signals such as Dish Network and DirecTV, virtually eliminating rain fade. Restored dishes fitted with block upconverters can be used to transmit signals as well.

Modern Equivalents

Large parabolic antennas similar to BUDs are still in production by companies such as Fortec Star and [http://www.samidish.com Standard Antenna Manufacturing Inc.] . New dishes differ in their construction and materials. New mesh dishes have much smaller perforations and solid dishes are now made with steel instead of fiberglass. New systems usually include a universal LNB which is switched electronically between horizontal and vertical polarization, obviating the need for a failure prone polarotor. As a complete system they have a much lower noise temperature than old BUDs, and are generally better for digital K_u reception. The prices on these dishes have fallen dramatically since to first BUDs were produced from several thousand dollars to as little as $189.00 as of 2008 [ [http://sadoun.com/Sat/Products/Fortec-Star/Dishes/FS6P-180P-CM-C-Ku-Prime-Focus-Dish-Polar-Mount.htm 6.5' Fortec Star with Polar Mount] ] . Typical uses for these systems include receiving MPEG2/DVB free to air signals and cable and DBS headends.

References

[http://www.geo-orbit.org/sizepgs/tuningp2.html#anchor715739 C/Ku Band Satellite Systems - Tuning, Tracking...]

External Links

[http://www.geo-orbit.org/sizepgs/tuningp2.html How to set up and align a BUD]
[http://sadoun.com/Sat/Order/Satellite-systems/C-Band-Satellite-System.htm Modern BUD systems]
[http://www.gofastmotorsports.com/rickssatellitelnblnbf.htm LNBs and other parts for BUDs]