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Old 10-22-2008, 04:32 PM
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Default Circular Vs. Linear satellite signals, The Differences and What you Need

Circular Vs. Linear satellite signals, The Differences and What you Need

Background; Satellite programming by the providers uses two different transmitting formats Linear and Circular, I will try to explain the differences. The Satellites have a number of transponders these transponders each carry a number of channels that we tune in on our receivers. The satellites can transmit through the transponders, two different type of signals, these are Linear or Circular.

The Linear transponder sends the signal from the satelite in a straight "plane", there are two planes used, Horizontal and Vertical. If you could picture a cardboard box with a slit cut in it just slightly larger than a "Frisby" (the thing you throw at the beach). If you place the box with the slit Horizontal and throw the Frisby in a Horizontal plane (and were a great shot) it would go into the box, and If you turned the box with the slit vertical (up and down), to get the Frisby into the box you MUST throw in the Vertical Plane to get it into the box. The transponders send both Horizontal and Vertical signals and the LNB and receiver sorts them out. Our LINEAR LNB's on the dish is the same as the slotted box and our receivers send the LNB the signal to receive the Vertical or Horizontal Signal (turns the box).

Circular sends the signal that if you could see it it, would look like a corkscrew. The corkscrew can be right or left handed (twisted). The receiver selects the correct Right/Left Circular signal for the channel selected. Rather than call it Right/Left they used the older linear designation H/V.

The LNB's are setup physically internally to receive these type of signals, the majority of LNB's are setup to receive either Linear or Circular, however there are specialized LNB's that can receive both, such as the Invacom QLP series, however there are NOT common and I have never seen them used by any major providers.

LNB Reference Information
LNB control voltages 12.5 to 14.5V selects Linear LNB Vertical polarity, Receiving ODD Transponders, Circular LNB Right Polarity, DishPro LNB frequency output is 950 to 1450 Mhz (AKA Legacy default)
LNB control voltage 15.5 to 18.0V selects Linear Horizontal polarity, Receiving EVEN Transponders, Circular LNB Left polarity, DishPro LNB frequency output is 1650 to 2150 Mhz (Frequency Shifted up)


As a guideline, for the Americas, the major providers in Canada and the USA almost exclusively use CIRCULAR LNB's. If you want non-english programing, MOST uses Linear LNB's, however there are exceptions such as French in Canada uses Circular. There are sites that will specify the type of signal the satellite transmits such as Lyngsat.com.

Summing up, all "surplus" small (18 to 22 inch reflector) Provider Logo dishes and LNBs supplied by major providers in North America are CIRCULAR (these will work to receive the most popular circular "birds" 82/91 & 110/119). Most South American birds are Linear, and require a 30 inch or larger dish reflector and a Linear LNB.

Circular Satellites; Circular LNB, LNB Type = Standard/Single, LNB Freq = 11250Mhz, typically a Smaller 18 to 22 inch dish
61.5W Echo3, 77W Echo4, 82W Nimiq2, 91W Nimiq1&3, 110W Echo6&8, 119W Echo7, 121W Echo9, 129W Echo5, 148W Echo1&2

Linear satellites; Linear LNB, LNB Type = Universal/Standard, LNB Freq.= 10750Mhz, typically a 30 inch dish or larger dish
63W estrela, 71.8W nahuell, 79W amc5, 91W galaxy11, 93W intelsat6, 95W galaxy 3C, 97W intelsat5, 101W AMC4, 103W AMC1, 105W AMC15, 107.3W Anik, 111W Anik f2, 116.8W Satmex5, 123W Galaxy 10r, 127W Galaxy13

What is C band

("compromise" band) is a portion of electromagnetic spectrum in the microwave range of frequencies ranging from 4 to 6 GHz .

C band is primarily used for satellite communications, normally downlink 3.7 – 4.2 GHz , uplink 5.9 – 6.4 GHz , usually via 24 36-MHz transponders on board a satellite. Most C band satellites use linear Polarization , while a handful (particularly older Intelsat satellites) use circular polarization.

The applications include full-time satellite TV networks or raw satellite feeds, although subscription programming also exists. There are over thirty C band satellites in Geosynchronous orbit serving North America, which provide more than 1,000 video channels and countless audio services. In the past, direct C band reception was the only satellite television option available to consumers. Since the introduction of high-powered direct broadcast satellite systems, which normally used small 18-inch (45-cm) stationary dishes (in contrast to the large dishes and motors required by C band systems) in the middle 1990's , the number of homes using C band satellite systems in the United States for general reception has vastly declined while small-dish systems enjoyed unprecedented success. Despite this, C band satellites continue to be a key important distribution method for cable networks in the United States (to cable head-ends and mini-dish DBS services) and other network/broadcast users. For example, most satellite-distributed syndicated and network television shows are pre-aired for affiliate and Canadian pick-up by C band. Radio stations picking up satellite-fed programming also constitute an important American user of C band, with a major American radio "neighborhood" located on the AMC 8 satellite at the 139° W orbital position.

C band came into domination in the 1970s with the launch of Canada's Anik satellites, and Western Union's Westar and RCA's Satcom satellites.

Beginning in 1984, the major networks transitioned to full-time satellite delivery for television programs. ABC established a satellite home on the Telstar 301 satellite and later Telstar 302, and CBS launched two transponders on GTE's Comstar D4, later transitioning to Telstar 301 and Telstar 302. NBC maintained a C band feed for the east coast on RCA's Satcom 1R as part of its Skypath affiliate feed service for many years, but opted for Ku band delivery of West coast programming, and other affiliate feeds.

Typical Antenna sizes on C band capable systems for home reception in North America range from 6 to 12 feet (2 to 3.5 m). In other regions of the world, such as Europe and parts of Asia, considerably smaller dishes can be used due to high-powered satellites in this band and more distance between satellites in the orbital arc (as opposed to the two-degree spacing common over North America).

C band usage is less common in Europe, where the Ku band has traditionally dominated. In many parts of the world, C band is often used to cover a very broad area, for example all of Africa or China. Indeed, many C band satellites have "global" beams with gigantic coverage areas. For example, the global beam of the Thaicom 3 satellite, positioned at the 78.5° E orbital slot (over the Indian Ocean) has a coverage range extending over most of Europe, Asia, Africa, and Australia.

C band direct-to-home reception contrasts with the newer and now more common direct broadcast satellite, which is a completely Closed system used to deliver subscription programming to small satellite dishes connected to proprietary receiving equipment.

C band is highly associated with TVRO satellite reception systems or "big dish" systems. Larger antennas and more expensive receivers, C band usually provides better video quality and is less affected by rain attenuation than the Ku band.

C-Band signals have 4 digits (eg. 4100 )

C-Band LNB's use an L.O. of 5150

A primer on Circular LNB’s for Newbes: by Grandpooba

Background:
“LNB” is an Acronym for “Low Noise Block” down-converter.
The LNB is the item on the receiving dish with the “white hockey puck nose”.
The LNB is one of the most important items in your system, as it determines what satellite you can watch, and the features of the LNB control one, or multiple receivers.
The major providers satellites in North America transmit on the ku frequency band and transmit a circular signal for the most popular satellites located at 110/119 & 82/91 west. A Circular receiving LNB MUST used to pick up these satellites. These are commonly available new through satellite resellers and on the secondary (used) market, through dealers, on line auctions etc, often attached to a dish.

RULES for fixed dishes
The First rule: ONE LNB (white hockey puck nose) for EACH satellite you wish to receive, connected to the receiver. Note: some provider’s build 2 or more LNB’s into one body, there are several variations of these.
The Second rule: the dish assembly, with LNB(s) must be aimed and signal peaked for the satellite(s) you want to receive.
The Third rule: Your receiver (STB) MUST be setup to the Satellite(s) and LNB(s) parameters.

Types of ku Circular LNB's
The major providers use two different type of electrical out put schemes, these are “Legacy” and “Dish Pro”(DP). The Legacy is the most common, is the older system and is more readily available and has more accessories available. The DP is newer, has the capability of longer cable runs to the receiver (greater than 100 ft.) However is limited for multiple satellite installations. (Difficult in installations of more than 3 satellites with more than 2 receivers). Identifying the type of LNB, Dish Pro LNB are marked on the back and on the body below the hockey puck nose in large letters “Dish Pro” and on both sides “dish network”. If your LNB is not so marked, you have a “Legacy” LNB. Both of these LNB’s types cannot be interchanged with each other in the same system.

LNB Configuration:
Single LNB (one hockey puck nose), on a aimed dish, can pick up one satellite.
It comes with one or two cable outputs. The Legacy LNB with one cable output, it will feed one receiver only, with two cable outputs, it can feed 2 OR MORE receivers through external switches, these switches can accommodate up to 8 different satellites. The Dish Pro LNB with one cable output, it will feed one or more receivers using a DP34 switch, with two cable outputs can feed 2 receivers (using a Diseqc switch). Note: The Dish Pro LNB can accommodate many receivers using DP34 switches, but the DP34 switches are limited to a maximum of 3 satellites.


Twin LNB’s (two hockey puck noses in a common body) These are 2 single LNB’s with a built in switch that is controlled by the receiver to switch from one satellite to the other and is controlled by the receivers command signal. The Legacy Twin LNB uses a 22kHz control signal, and the Dish Pro Twin LNB uses the Diseqc switch commands from the receiver. The twins are used to receive 2 satellites with one dish, however the satellites are pre-selected sets, these are 110 & 119 or 82 & 91. A requirement is that the dish must skew (pivot on its center axis), as each LNB has to match the satellites arc in the sky from your position. A excellent satellite-aiming site that will give skew for your location is Satellite look-angle calculator.

Receiver setup for circular LNB’s and satellites.
The satellites that the Circular LNB’s and FTA receivers can currently pick up in the America’s are 61.5 / 77 / 82 / 91 / 110 / 119 / 129 / 148 West.
To setup your receiver for a satellite and a dish, first you must gather the following information;
Satellite name/location (ES 7, 119)
LNB Type (Legacy or DP)
Configuration (single or twin)

Receiver setup: Load the current software for your Manufacture and model of your receiver available on this FTA site, following the downloading instructions, Note: the programs that are downloaded from any site will be “zipped”, you MUST un-zip them before loading into your receiver. Go into your receivers setup menu and select dish settings,

First select the satellite you want to setup,

LNB Power ON

LNB Type STANDARD (LEGACY or OCS-DPS for DISH PRO LNB)

LNB Freq. 11250

22KHz OFF (this switches the Legacy Twin, 22kHz off = 119, 22kHz on = 110)

TP Freq. 12224 (Use 2239 if 12224 doesn’t show YELLOW signal strength bar–12224 is a Spot Beam TP

DiSEqc 1.0 (this switches the Dish Pro Twin, Diseqc Port 1 = 119, Diseqc Port 2 = 110) for Legacy = None or off

Motor OFF

If your dish is aimed and your receiver is setup for your LNB, you can scan for channels, select standard or blind scan, and scan the satellite. The difference between Standard and Blind scan, Is the standard scan uses a transponder list that is in the receiver downloaded software. A Blind scan, looks for the transponders first, and than scans the found transponders for channels. A standard scan is much faster than a blind scan.

What is KU band

The Ku band ("kay-yoo" kurz-under band) is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 12 to 18 GHz.

Ku band is primarily used for satellite communications, particularly for satellite backhauls from remote locations back to a television network's studio for editing and broadcasting.

Ku band is split into multiple segments that vary by geographical region by the International Telecommunication Union (ITU). Several highly used segments in the Americas (ITU Region 2) are:

The 11.7 to 12.2 GHz band is allocated to the FSS (fixed service satellite, uplink 14.0 to 14.5 GHz). There are more than 22 FSS Ku-band satellites orbiting over North America, each carrying 12 to 24 transponders, 20 to 120 watts per transponder, and requiring a 0.8-m to 1.5-m Antenna for clear reception.

The 12.2 to 12.7 GHz segment is allocated to the BSS (broadcasting satellite service. BSS/DBS direct broadcast satellites normally carry 16 to 32 transponders of 27 MHz bandwidth running at 100 to 240 watts of power, allowing the use of receiver antennas as small as 18 inches (450 mm).

Ku-band signals can be affected by rain attenuation (rain fade).

NBC was the first television network to uplink a majority of its affiliate feeds via Ku band in 1983.

KU signals have a 5 digit Frequency (eg. 12052 )

Standard KU LNB's use an L.O. of 10750

Universal KU LNB's use an L.O. of 9750-10600

DBS LNB's use an L.O. of 11250

Last edited by Fta Professionals; 10-23-2008 at 04:36 PM.
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