My ITV/C4 Freeview channels have disappeared - what can I do? Is it my SCART ca
Brian Butterworth published on UK Free TV It is a feature of television signals that they can be effected by the weather. Aside from the obvious damaged that can be caused by wind or torrential rain, the onset of summer can cause a more intriguing problem called "inversion".
Basically, when the sun heats up the land, the hot air can get trapped below cold air at high level. This creates an "inversion layer" which acts like a polished mirror to TV signals. This causes two problems: you can receive both the original and a reflected signal from your own transmitter (on analogue TV this appears as "ghosting") or interference from TV transmitters that are normally too far distant.
The ITV/C4 multiplex of channels (ITV-1, ITV-2, ITV-3, ITV-4, CITV, C4, More4, E4, Quizcall) use a transmission "mode" called 64QAM, and it is sadly much more prone to these problems.
So, whilst a loft-mounted aerial will provide reception at some time, it will fail at others. The only real solution is to mount the aerial (or a new Class I aerial) outside on a pole, but some people report that changing the cable from the aerial to the set-top box to the high-grade satellite cable can also help.
The SCART connection, by the way, only carries a single TV picture, not the Freeview transmission multiplexes, so if this is disconnected it will result in degradation to every channel at once.
12:43 AM
Jen Franklin: Which transmitter does your aerial point to? Which way does your aerial point and are the elements horizontal (flat) or vertical (up/down)?
Looking at your road on Google Street View, aerials are pointing different ways, to different transmitters, a testament to the difficulty of reception in the area. At digital switchover a new transmitter started up in Bexhill, albeit carrying the PSB multiplexes, meaning many channels not available.
Many aerials are pointed to Heathfield, and if this is yours then it is down as having engineering works. As you are in a poor area for reception from Heathfield, if it is on reduced power then perhaps this would explain your issue.
The full list of Freeview channels is here:
Channel listings for Industry Professionals | Freeview
Which ones are you missing? The "Mux" column identifies which multiplex they are carried on. If you are missing one programme channel on a particular multiplex you will be missing them all because it is the multiplex which you are not received.
The main multiplexes are:
PSB1 = BBC A
PSB2 = D3&4
PSB3 = BBC B
COM4 = SDN
COM5 = Arq A
COM6 = Arq B
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