All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.
Briantist: "To replicate the previous analogue provision, Ridge Hill West will provide a dedicated D3-4 mini-mux carrying only the ITV1 West regional variant."
http://www.digitaluk.co.u….pdf
I think ITV1 +1 was added as well, though because of ITV's macro-region policy this is Wales rather than West (still different from the full D3&4 mux which carries ITV1 +1 Central West). Possibly it will eventually become West.
Nulling packets out of the full multiplex shouldn't be that hard, indeed you could probably just suppress the Programme Map Table for the services you don't want receivers to pick up! If you did that, all the actual vision and sound data would be received by the relays and you'd only have to add the PMTs back in. You could even carry the PMT data in a private packet that the relays knew how to turn back into the correct PMT data, though of course you run the risk that some badly-implemented boxes wouldn't interpret the munged data from the original transmitter correctly.
This does assume the transposer equipment is capable of a full decode and re-code and allows the transport stream to be modified between those stages.
Fun speculation, but probably not practical!
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Adrian Crafer: It is on Digital UK's list at http://www.digitaluk.co.u….pdf .
Sorry, it's new box time for that one. See
Digital Switchover UK - Pace
for Pace's information.
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Ryan J: For the aerial, you'd need a Freeview box. For the satellite dish, a Freesat box, or a Sky box. If there are two feeds from the dish you can get a Freesat+ or Sky+ recorder.
Compare the non-subscription channels available at Compare Freeview and Freesat TV | ukfree.tv - independent free digital TV advice .
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Alan: Yes, you need to ensure the existing channels are deleted on switchover days, and the easiest way to do this is through Default Setting.
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Sam Millar, Robert: Some boxes do have trouble with very different levels between the multiplexes, which will be the case for the next two weeks.
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Jimjams: In the Tyne Tees region, only the Pontop Pike transmitter currently broadcasts an HD service, and it does so on C63.
If your aerial points to another transmitter, for example Fenham, HD services won't start until the second stage of switchover on 26 September 2012.
At the postcode you've given, Digital UK predict an excellent chance of reliable reception of all services from Pontop Pike. You will need to get the aerial pointed at that transmitter. If you currently get Multiplex D services reliably, you shouldn't need a new aerial, as it will already be a wideband. If not, it's probably a Group A - Pontop Pike transmits in Group C/D.
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Jimjams: Sorry, I just noticed that you provided a pair of co-ordinates, not a postcode. You'll have to take the prediction with a pinch of salt, or provide a full postcode for a more accurate one.
If you're using a communal aerial you will have to check with the building's owner. If the aerial is definitely pointing to Pontop Pike, the distribution system might be channelised and not set up to amplify C63 at the moment. I assumed Fenham because this is the page for C21, and Fenham will use C21 for HD services after switchover.
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Peter: If you are using the Oxford transmitter itself, and you must be if you had digital before DSO started, works were completed by 6am. Some of the relay transmitters take longer as they get the main transmitter sorted out first, then move on to the relays.
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Peter: Digital UK's predictor shows a very good chance of reliable reception from Heathfield at your location, once switchover starts. It gives no prediction now.
Being right next to a relay is no guarantee that you'll be able to get services from the main transmitter. They often use aerial diversity - arrays of aerials, sometimes at radically different heights or on different legs of a tower - to get better rejection of unwanted signals, and usually have more sensitive equipment than your typical domestic receiver. Also, they can frequently put the receive aerials higher up than a normal domestic installation, though this isn't always the case.
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Tuesday 13 September 2011 11:20PM
JohnC: For satellite, the box can instruct the LNB to select high or low frequency range, and vertical or horizontal polarization. In communal systems, the LNB instead outputs each combination - Lo/H, Lo/V, Hi/H, Hi/V - on a separate cable, and the four cables are connected to a multiswitch. The wall socket(s) in your flat are connected to that multiswitch, which selects the correct output depending on what the box is sending on that cable.
You cannot split a satellite feed cable for multiple boxes, because the signals either don't make it back to the LNB or multiswitch, or the splitter only passes the signals from one leg - the second tuner won't be able to select the correct range and polarization for the channel you've selected.
If you're just using a single cable to the one wall socket, and it still doesn't work, then the answer is probably a bad connection or water ingress into one of the cables from the LNB to the multiswitch.