Installing satellite TV reception systems can be a complex issue, and if a system fails to operate due to reasons beyond the service provider’s control, it may be necessary to use self-help remedies. Sometimes there is a need to improve facilities because an installed satellite dish underperforms. Dishes can be adversely affected by by local conditions such as the proximity of other buildings and structures. In these circumstances, it may be worth considering upgrading the twin Low Noise Block downconverter, or LNB, device that comes as standard with a satellite dish.
There are two types of individuals looking to purchase a twin LNB device. Individuals who are confident technicians, and those who may need more handholding through the purchasing process when it comes to replacing or upgrading an LNB. Due to the technical complexities and the rapidly changing nature of this type of technology, some simple guidelines may be helpful to both types of purchaser. Distinguishing between the multitude of products on the market where terminology is not always consistently applied is important if a successful purchase is to be made.
Low Noise Blockers: What Do They Do?
Satellite signals and the signals that television sets process are in completely different frequency ranges. This means that in order for a TV set to process a satellite signal, it has to be converted from the higher range microwaves used by the satellite to a lower range that can be processed by a TV set. The signal also needs to be converted to a lower frequency range so that it can be transmitted over coaxial cable which is a cheap and readily available medium.
The satellite signal is collected by a curved dish, and the signals are focussed on a given point where they are collected by a Low Noise Block downconverter. Each twin LNB is specific to the satellite it is receiving signals from. When satellite TV transmissions were first launched, a single signal from a single satellite was all that was necessary to enjoy a wide variety of program choices. However, as the market matured and more satellite services were on offer across multiple territories, a single LNB was no longer sufficient. The variety of LNBs available increased even further with the advent of digital TV.. This type of TV led to services where more than one signal was required to deliver programs. Consequently, it became necessary for satellite dishes with new types of LNB devices.
Universal, Twin, and Dual LNB
The terminology and labelling applied to LNB devices is not unique across all marketplaces. Consequently, it is possible to see LNB devices from overseas markets such as the United States, where the terms used to describe them are not consistent with terms used in the United Kingdom.
A universal LNB is one that is capable of receiving any of the four types of signals a satellite transmits, although this type can only receive one at a time. It is not a "one size fits all" LNB device. The application of the term "universal" to a modern LNB is somewhat redundant, as an LNB can only operate with one of the four types of signals transmitted by a satellite.
With the advent of digital satellite broadcasting and the launch of services such as Sky+ and Freesat in the UK, a new type of LNB was required. Twin LNBs receive and decode more than one signal from the same satellite at once. A twin LNB is easily identified by the twin coaxial output ports at the base of the device. Twin LNB devices enable the provision of key functionalities, such as watching one program whilst recording another, that modern digital satellite services offer.
A dual LNB differs from a twin LNB in that it is designed to capture and downgrade signals from two satellites. The signals are transmitted to the decoder box across a single coaxial cable, and it is the decoder box that selects the particular signal that is being received at a given time. This type of device is designed to allow programming from two satellites to be viewed, but not at the same time.
Round or Oval LNBs
A twin LNB is made to receive the signal from a specific satellite. It is also designed to receive the collected signals from a satellite dish that is a particular shape. Mini dishes, round dishes, or oval dishes all collect and bounce satellite signals in a particular pattern to the feedhorn part of the LNB. Inside the feedhorn, a series of concentric rings or ovals are placed to capture the collected signals.
The shape of these rings must correspond to the shape of the satellite dish. Oval rings placed on a round satellite dish can lead to signals from outside the dish being collected and passed to the digibox for processing. Most often, this is in the form of signals readily bounced back from the wall where the dish is mounted. This can result in poor quality signal reception, and therefore it is important to purchase an LNB that is designed to operate with a specific dish shape.
Why Purchase a New Twin LNB?
For many satellite TV users, their understanding of twin LNB technology can remain scant. The only time that an individual normally needs to know how to buy a twin LNB is if the equipment failed or if the user wished to upgrade services without going through one of the major service providers.
Bad Weather and LNB Performance
Over a period of time, water ingress combined with the freeze-thaw cycle associated with weather during a British winter can lead to degraded performance. Moisture that builds up in a twin LNB can freeze during the winter, and the expansion of the water as it freezes can lead to fractures in circuit boards and between solder joints. Modern twin LNB devices remain powered up, even when they are in standby mode, and the current moving across the twin LNB is sufficient to stop the freeze-thaw cycle from occurring. However, older devices may not necessarily have a standby mode. In the longer term, satellite dishes fitted with these twin LNB devices may provide poor or unusable signals. In these cases, it may be necessary to replace the twin LNB.
Foolproof Buying of the Right Twin LNB
For novice or advanced users, purchasing a twin LNB can be a complicated issue. A more straightforward way of negotiating through the technical minefield is to purchase an LNB that is marketed as being the correct twin LNB for the installed service. Buying a twin LNB that is marketed for a Sky+ or a Freesat service, for instance, ensures that the technical specifications match those of the equipment concerned. The chosen twin LNB should match with the required satellite transmissions and with the correct satellite signal. It should also work with the specific satellite dish shape the service requires and have the correct mounting mechanisms to ensure it fits in the dish.
Buying the Right Twin LNB on eBay
Purchasing a twin LNB can be made very simple by using the eBay online shopping platform. The features and facilities of eBay have been designed to make the retail experience as straightforward as possible. To start your shopping experience, simply log on to the eBay homepage and key in "twin LNB" on the search bar. eBay displays all of the listings that have "twin" and "LNB" in the description.
If there are too many listings for you too look through, you may choose to narrow your search by including extra words. You may be looking to purchase a twin LNB for a particular satellite service. You can include a specific name, perhaps "twin LNB Sky" or "twin LNB Freesat", in your search to create a shorter, more specific group of relevant listings to look through.
It is also a good idea to check a seller's credentials. You can see how other eBay buyers have rated a seller by simply clicking on the seller’s name. Taking a few minutes to see what other items of this type the seller has sold and how eBay buyers have rated their transactions is a useful step in buying with confidence on the website.
Since the advent of satellite television in the 1980s, LNB devices have performed a central function in providing signals into individual homes. As satellite broadcasting has become more widespread and digital TV has taken over, there is a need for more complicated services that include twin LNB devices. Twin LNB devices are widely available, and making a successful purchase involves clearly understanding the services each type of LNB is designed to work with.
eBay’s powerful search functionalities allow users to generate relevant listings so that informed purchasing decisions can be made. The clear descriptions of twin LNBs on eBay allow technicians and novice home users to review and make purchases quickly and easily.
eBay has a wide range of twin LNB devices on sale, and the list is constantly being updated as new sellers add their products to the platform. The range is much wider than what traditional retailers offer. Additionally, buyers benefit from the fact that eBay is open for business 24 hours a day, seven days a week.