TV Links

Analogue, digital terrestrial (DVB-T / Freeview) and satellite (DVB-S). Here are a few links I have found useful. See also our Freeview reception tips.

Media UK	News, links, station info, RSL/Satellite/Internet radio info, presenter lists etc.
Digital Spy	Radio and TV (inc. satellite and digital) news, covering content, transmission and reception. Comprehensive forums.
Wildsat	Frequently updated station lists and tuning details for Sky and FTA statelite users. (Frequently updated)
Satcure	Spares, accessories, kits and much info for satellite, Freeview etc. Also several useful e-books
JW Hardy	Supplier of aerials, dishes, amplifiers and radio/tv distribution kit
DVB-t Tx info	Digital terrestrial transmitter info.
Sky Freesat	Sky TVs little known subscription free option.

Freeview Tips

Digital Terrestrial (Freeview) TV reception presents a number of problems above that of analogue TV. The following advice and tips may be useful when installing Freeview equipment.

Note: Freeview is not available in some areas. Freeview is also not usually carried by relay transmitters, so if you get your conventional analogue TV via a relay transmitter you may not be able to receive Freeview, and if you can, you may need a new aerial, pointing to a main transmitter.

How do I know if my aerial uses a main or relay transmitter? Well in general, main transmitters use horizontal polarisation for their signal, whereas relay transmitters tend to use vertical polarisation. So if your aerial is mounted whith the elements horizontal, chances are you are using a main transmitter.

Freview channels are generally transmitted at a much lower power than conventional analogue TV. This may not be a problem since Freview receivers need much less signal to work effectively, as long as the signal is strong enough to enable the receiver to distinguish between the ones and zeros in the signal. If this is the case, the receiver should be able to perfectly re-construct both picture and sound.

With conventional analogue TV, the signal can degrade significantly, but still remain watchable. With digital though, there is a threshold, which means if the signal deteriorates slightly, your reception can quickly go from perfect to useless.

Digital is particularly prone to co-channel interference, where atmospheric conditions cause long distance reception from multiple transmitters on the same frequency. This can quicklly wipe out large numbers of Freeview channels as several channels are multiplexed together on the same frequency. There is not a great deal that can be done about this, although improvement may be able to be made to the aerial system to reduce this. Amplification will definitely not help here.

Another problem is impulse interference, which can temporarily corrupt the received data stream, causing picture break-up, sound squaks etc. This type of interference is often caused by electrical switches, central heating thermostats, fridge door light swithces etc. Here, the name of the game is to shield the signal as much as possible, so what comes in from the aerial if fed cleanly to the receiver.

To maximise and protect your signal, a good quality aerial will be needed, although, often a standard areial will surfice. Masthead amplifiers can be useful, but they should be well screened types, designed for digital use. The most important thing is often overlooked. Use a GOOD quality aerial cable from the aerial to your receiver. Standard 'TV Coax' is just not good enough, the screening is too poor, causing signal loss and allowing interference in. Use a good satellite quality cable, with both a copper braid and copper foil screen. CT-100, H109 or equivalent specification. If the cable has to be a particularly long run, consider higher spec. CT-125 cable instead to preserve the signal.

Try to avoid unnecessary connections in the cable and use good quality plugs and connectors. Standard TV coax plugs (also known as Belling-Lee plugs) are available in various different types. Avoid the cheap plastic bodied types, these are highly prone to bad connections. Aluminium types are much better. Better still are chrome plated types, as they are less prone to corrosion, however, where the centre conductor is fixed by means of a screw, care must be taken that the screw does not short out on the outer body of the plug.

By far the best type of connector is the F connector. This is the type used in satellite installations and is both simple and reliable. With these connectors, the centre conductor of the cable is used as one pin, the F connector screws or crimps onto the outer braid and insulation. The F plug then screws securely to its socket. Where cables have to be joined, use two F connectors and an F barrel coupler. Where the cable connects to the standard Belling-Lee connector on the receiver, use an F connector on the cable, then screw this into an F to Belling-Lee adaptor.

Set-back amplifiers are unlikely to be of much use, as they merely amplify an already degraded signal, furthermore all amplifiers will add a degree of noise to the signal, so could make matters worse.

It is a myth that digital TV gives a better picture than analogue. As there are several channels multiplexed onto one frequency, all sharing the same bandwidth, detail is often sacrificed. This is often noticeable by pixelation in fast moving or dark scenes. This is not a signal or receiver problem, merely the result of trying to squeeze too much information into too little bandwidth.