Something that often throws people when setting up a satellite decoder is what setting to use for the Local Oscillator (L.O.). Freeview approved decoders and some others use a system called ‘blind scan’ which eliminates the need to know any settings, you simply set the decoder to auto search and it will cycle through all the possible settings until it gets signal. For most satellite decoders though you need to set the L.O. manually.
For Sky TV dishes there are about 5 different models of LNB, utilising two different frequencies. Other dishes usually use one of the same frequencies, but there are also a couple of less common frequencies. The most foolproof way of finding out is to look at the sticker on the LNB, however this does mean gaining access to your dish, which may not be possible (or safe), or the sticker may not be readable.
‘Sharp’ Sky Single LNB – 11300 L.O.
The older Sky dishes, and most other dishes use an L.O. frequency of 11300 MHz (11.3 GHz). There are a number of models that Sky have used over the years.
‘California Amplifiers’ Sky Single LNB – 11300 L.O.
One of these models in particular can prove troublesome – The oldest model, the ‘California Amplifier’ LNB (pictured above) doesn’t always allow use with 18V (horizontal polarity). The majority of these have been upgraded, but they still show up occasionally where the dish has not been used by Sky for a few years. They also suffer from UV damage with the face often become brittle, cracking, and allowing the ingress of water. If you have one of these LNBs and it is showing signs of deteriorating you are best to replace it.
‘Sharp’ Sky Dual LNB – 10750 L.O.
Newer Sky dishes have what is known as a Dual LNB with an L.O. frequency of 10750 MHz (10.75 GHz). These LNBs are recognisable by the oval shape of the face, and the twin throats on the body. Sometimes the L.O. of these can ‘wander’, setting your L.O. to 10740 or 10760 may fix this problem.
‘Sharp’ Sky Quad LNB – 10750 L.O.
Sky has released the Quad LNB pictured above which is pretty much identical to their Dual LNB, but with four cable outlets in the LNB itself, and slightly longer in the body. This is now the standard Sky LNB for all new installs, and older ones will be progressively replaced with these. Plastic caps cover the extra 3 cable outlets in the picture. It has a built in multi-switch with four outlets allowing the MySky HD decoders plus additional decoders to access either satellite simultaneously, unlike their Dual LNB which can only ‘see’ one satellite at a time. The naming they are using is a little confusing, the Dual LNB has dual throats to look at two satellites, but a single cable outlet. The Quad LNB still has dual throats, but is equipped with quad outputs.
Dual LNB (non-Sky) – 10600 L.O.
There are a few LNBs around that have an L.O. frequency of 10600 MHz (10.6 GHz), though these are relatively uncommon. Above is one such LNB. Most often than not though they will resemble a standard single LNB, and you won’t be able to tell until you check the sticker.
Setting the ‘LNB type’ in the decoder is usually hit and miss, we’ve found it often varies between different manufacturers and LNBs. Setting the LNB type to ‘normal’ usually works, but you may need to set it to ‘universal’ with some. For smaller dishes under 1.5m in size the LNB band will almost certainly be Ku. C band is only really used with large dishes for foreign channels.
Top Left – Newer California Amplifiers LNB – 11300 L.O.
Top right – another ‘Sharp’ single LNB – 11300 L.O.
Bottom – ‘Hills’ dish – 11300 L.O.
The Hills dish above was used by Sky for a short time when they had problems with their supply of Winegard dishes. The LNB on these is white with a metal casing in contrast to the normal plastic ones. Later Hills models use a whitish coloured LNB very similar to the one top right in the picture above.
For non-Sky installed dishes there isn’t really any way of telling what the L.O. frequency will be without looking at the LNB sticker. There are dozens of different models from different manufacturer’s on the market, and installed on houses. More often than not a recently installed dish will have an LNB with a 10750 L.O as most commercial installers have followed Sky’s lead, and are trying to keep things simple by matching their setups to Sky’s.