Why are they switching analogue off?

[rolfw]

It wouldn't work, as your aerial will be either vertically, or horizontally polarised and couldn't efficiently receive both polarisation.

Digital multiplexes can be on adjacent channels anyway, so there is no necessity.

 

[PaulR]

why dont they use vertical and horizontal polirisations on the same transmiters . or is this the plan when analouge is turned off.

Originally the plan was that all main transmitters would use horizontal polarisation and any fill-in transmitters would use vertical polarisation. This would reduce interference and allow re-use of frequencies more often as you go across the country.

 

[Topper]

Originally the plan was that all main transmitters would use horizontal polarisation and any fill-in transmitters would use vertical polarisation. This would reduce interference and allow re-use of frequencies more often as you go across the country.

Isn't that what they already do with analogue?

 

[2cvbloke]

Isn't that what they already do with analogue?

Can't be if I can receive 4 channels at different frequencies (ok, the 2nd lot are weak, but a different frequency though!!!)....

 

[Topper]

Yes sorry I meant the horizontal and vertical, all main are horizontal and fillin are vertical IIRC.

Obviously if the frequencies were the same they would would interfere, or would they if they were the same channel, did any one ever test that? haha
I sure the boffins covered all bases at some point. I live behind a hill so my reception from Winter Hill has always been blocked but as digital is not transmitted on fillin transmitters like Haslingdon I have had to revert back.

 

[PaulR]

Analogue or digital, it makes no difference. Horizontal = main, vertical = fill-in.

Or at least it was until, round here, the Storeton repeater was built to service the parts of Liverpool that were shaded from the Winter Hill transmitter. Despite the general plan it was given horizontal polarisation. This was back in the old analogue only days but when digital came along this too was horizontal. And this was just a repeater, albeit quite big one, don't forget - one of the few that transmit digital I think.

The other repeaters round here transmit only a few watts of analogue and only the four main channels at that! I belive that they won't go digital until the very day that analogue gets switched off atWinter Hill although I have also heard an alternative theory that they they will go gradually digital, losing one analogue channel to a digital mux in the run up to the big switch off.

Luckily I get a good Winter Hill signal and none of this repeater malarkey affects me!