Checking channels
You are quite likely to find you can get good reception on several stations
but others are poor, with the picture breaking up, or nonexistent. Try:
BBC1, ITV1, QVC (the shopping channel), BBC4 (evening) or CBeebies (daytime),
The Hits and Sky News.
If you can get good reception on these channels, you can be confident
that your aerial will receive all the channels and radio stations. Try
shifting
the position of the aerial for any of the six channels if you
don’t
get them immediately.
Multiplexes
There is a simple reason to be confident from checking just six
channels rather than about 50 TV and 25 radio stations. Unlike conventional
analogue TV, where each station has its own frequency, digital TV
squeezes a group of stations, called a multiplex, on to each frequency.
In all, there are six of these. For example,
most BBC stations are broadcast together on ‘multiplex 1’.
This means that, if you can get a good picture on BBC1, then you should
get a good picture on several other BBC channels. You need check only
one channel from each multiplex.
You may find that you have good reception on some multiplexes, but others are not so good, with the picture breaking up. If so, it may be worth taking your aerial back and trading up to one we recommend with an amplifier. Our tests show that an amplifier can make a difference where reception is nearly there but the picture is breaking up.