[Voiceedit]

This is a call to you technical experts out there. Is it now possible for a transmitter to send out an analogue station and a digital Mux on the same Channel with the same polarisation and similar radiation pattern without interference?

[Trollslayer]

No, they would interfere with each other.
The networks are planned so different transmitters don't cause this.

[grahamlthompson]

Originally Posted by Voiceedit

This is a call to you technical experts out there. Is it now possible for a transmitter to send out an analogue station and a digital Mux on the same Channel with the same polarisation and similar radiation pattern without interference?

An analogue station uses one uhf carrier, digital has multiplexed digital channels onto a uhf carrier. There's only one carrier possible at one frequency from one transmitter (and can't be used by any other transmitter in range either) so it's physically impossible

[Voiceedit]

Thank you both. That's as I thought but I was beginning to doubt my sanity. You have now restored that.

My reason for asking is that I've been trying to establish exactly what will happen in March/April 2010 when the Mendip transmitter experiences the DSO. It's proven very difficult to obtain channel details which make sense. At DSO1 on 24 March it seems clear that BBC-2 analogue on Ch 64 will cease. BBCA mux will then start up in full power on Ch 61. But Ch 61 is already occupied by ITV-1 analogue.

I sent a query about this to Digitaluk and the reply I received stated that BBCA mux will start up on Ch 61 and ITV-1 analogue on Ch 61 will continue!

I've now sent back a query about the sense of this and await the reply. Does it seem likely that, in fact, ITV-1 analogue will, at DSO1, actually move from Ch 61 to Ch 64 (the old BBC-2 analogue channel) until DSO2 on 7 April when it will cease?

[grahamlthompson]

Originally Posted by Voiceedit

I sent a query about this to Digitaluk and the reply I received stated that BBCA mux will start up on Ch 61 and ITV-1 analogue on Ch 61 will continue!

I've now sent back a query about the sense of this and await the reply. Does it seem likely that, in fact, ITV-1 analogue will, at DSO1, actually move from Ch 61 to Ch 64 (the old BBC-2 analogue channel) until DSO2 on 7 April when it will cease?

Oh dear Oh dear , they must get technical advisors from the same labour exchange as Comet, Currys and the ilk. We all know what happens when atmospheric conditions cause TV transmissions to go futher than normal bringing distant stations in range using the same uhf frequency. Analogue transmissions very pretty patterns, digital reception blank screens or unwatcheable. You can actually try this yourself if you have any equipment with a built in UHF modulator. A modulator takes the audio and video output of the box and modulates it onto a UHF carrier creating it's own analogue transmission at the uhf channel you choose. Try setting the modulator output to the same uhf channel as a digital channel used by your transmitter and then to the same as an analogue channel used by yuor transmitter. Try and view these channels in turn on a TV downstream of the modulator

[Voiceedit]

I have now received a further reply from Digitaluk which confirms my suggestion as to what will happen in my previous comment on this thread, ie ITV-1 analogue will move to the released BBC-2 channel allowing mux BBCA to occupy Channel 61. Anyone still viewing analogue between DSO1 and DSO2 dates will obtain ITV-1 analogue by pressing "2" on their remote. Pressing "3" will be met with a blank screen.

Now when were they actually going to divulge this information?

I suggest this thread can now be considered closed. Thank you to the two respondents.