Home Digital TV benefits
TV Reception Problems?
This test assesses the benefits of Freeview digital TV (DVB-T) compared to the UK analogue television service under weak signal conditions with a poor aerial.
To prove the very real advantages of digital TV via an aerial, we made use of a cheap Freeview receiver from Matsui and set up a controlled experiment.
We set up a Set top TV aerial on the ground floor of our Newbury, Berkshire office pointing at the Hannington TV transmitter to get an equally poor signal on all Freeview channels and analogue TV, to assess any advantages of terrestrial digital television over the 'soon to be discontinued' analogue TV service.
We tested the likely reception benefits and advantages of Freeview TV transmissions comparing results with existing analogue TV, whilst simulating fringe area reception areas receiving a poor TV signal.
We were interested in whether homes receiving a poor analogue TV picture would be likely to see any benefit from buying Freeview TV. To find answers to these important points, we set up one of the cheapest Freeview receivers available and tested it to the threshold limits of digital reception here in Newbury, West Berkshire.
To our amazement, our cheap Freeview TV receiver worked well even under weak signal conditions from the Hannington TV transmitter with just the set top aerial. The same aerial gave very poor reception of all 5 analogue TV channels with considerable ghosting and picture noise. The pictures below clearly show the benefits in picture quality of terrestrial digital TV over analogue television under these weak signal conditions.
When directly comparing analogue TV versus Freeview under poor signal conditions, Freeview produced a picture which was far superior (see below). That said, some of the weaker digital channels (DVB-T multiplexes) from Hannington suffered from very occasional picture break up, but on the whole the reception was a whole lot better than the unwatchable analogue TV picture.
At the end of the test the benefits of UK terrestrial Digital TV were obvious! Similar results were obtained with fringe DTT reception from the Oxford TV Transmitter.
Freeview TV Picture
Analogue TV Picture
For many UK households, Freeview digital TV will give far superior results over analogue TV with good interference rejection and total freedom from fading or ghosting - problems which frequently arise with analogue TV reception. By 2012, all analogue TV services in the UK will be turned off, so all properties will need to buy a digital TV adaptor or Sky Digibox to continue viewing.
Freeview TV as with all digital television services uses MPEG2 picture compression technology to increase the efficiency of transmission, so that multiple channels can be broadcast simultaneously on a single TV channel in what is known as a "digital Multiplex". Freeview TV benefits from advanced error correction which cancels out the effects of interference and corrects data loss due to poor signal conditions down to the threshold of reception. Below this point, the error correction system employed can no longer cope and abrupt signal loss is experienced. If the received digital TV signal is already at the receiver threshold and then gets marginally weaker, reception will fail. Therefore it is advisable to ensure that all Freeview installations have a signal quality well above the threshold point for all digital multiplexes.
During the test, we deliberately subjected the cheap Freeview receiver to poor signal quality, looking for the classic symptoms of poor digital TV signal conditions : picture freezes, picture artefacts and dropouts.
It is interesting to note that the Freeview channels from the Hannington TV transmitter are transmitted at a mere fraction of the power of analogue services. Each Freeview multiplex is transmitted at a maximum power of 20kW with multiple TV channels occupying a single multiplex. The analogue TV channels each run 250kW per channel, (that's 25 times higher power than the digital service). The exception being Hannington Channel 5 which just runs 60kW.
The information contained on this "Freeview TV benefits" page is provided in good faith and is accurate to the best of our ability. No guarantees are offered concerning fringe area digital TV coverage.