All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.Penny: it sounds like your house was wired for Sky 'magic eye'. The cable has to be a continuous run from one box to the next so that the RF output from the Sky box is sent to all boxes, and the signal from the 'magic eye' box at each location gets back to the Sky box.
Otherwise, it's not normal to wire up a building like this - normally you split the aerial cable as close to the aerial as possible so the signal at each point isn't harmed by the noise generated in each box. Obviously in an apartment block you don't want each tenant's 'magic eye' interfering with each other - you don't want your box to change channel when your neighbour uses his remote!
Neil's problem is likely to be one for the building management company or landlord, to ensure that the signal levels are adequate at every provided aerial point. Unless, of course, they only originally fitted the main point in the lounge and the bedroom is different.
Neil: If the socket that doesn't work has a screw thread on it, rather than just a plain sleeve, that's probably a satellite point rather than an aerial point. It's amazing that it works at all, but you're so close to the Sutton Coldfield transmitter (11km) that there is a good chance of picking up a detectable signal just in the cable or TV, with no aerial connected to it!
| link to this comment |
Penny: a further thought - the wiring was probably intended for a Sky box, where you would plug the aerial lead from the socket marked 'TV' to 'aerial IN' on the box, and another lead from 'aerial OUT' to the 'return' socket. You need a 'Y' splitter because the TV doesn't *have* an 'aerial OUT' socket - it's not designed to chain up to another device or add its own output to the cable.
| link to this comment |
Trevor: I don't imagine *everyone* did. Multiplex D has not yet switched over, but it's possible that some interim change was made in preparation for the next change.
On the 13th, Mux D changes mode becoming ArqB and moves to C67, currently used by Mux B - generally the numbers got the best allocations, then A, B, C and D in that order. That may improve matters. However, some people may lose them due to the change in mode, which gives more capacity but requires more signal compared to the level of interference.
The final re-configuration for this multiplex is planned to be on 14 September.
Ofcom's latest stations table, incorporated into the licence by reference, says 'Until further notice, may use transitional antenna'. This is against the final configuration, so could relate to the situation after DSO. The notes for Multiplex 2 (D3+4) and B (HD) both say 'Use transitional S1 antenna until 27 June 2012', though this is probably to avoid clashing with another main transmitter that won't switch over until later - possibly Rowridge.
| link to this comment |
Rob: So far, only the main BBC multiplex has switched over. The rest of the multiplexes switch over on Wednesday 13 April.
| link to this comment |
David Howard: While the public service multiplexes complete switch over on the 13th of April, the commercial multiplexes don't complete until later in the year. Once they do, there will not be a clash. They have to move to get out of the way of Sutton Coldfield's switchover, in fact.
Multiplex A from Sandy Heath uses the same channel as ITV1 (analogue) from Sutton Coldfield, C43. Mux C (ArqA) uses the same channel as BBC Two from Sutton Coldfield, C40. It's likely that this will cause a noisy analogue picture on the TVs connected to the Sutton Coldfield aerial, and nothing much usable on these muxes on the TVs connected to the Sandy Heath aerial.
When Sutton Coldfield switches, C40 becomes the HD multiplex and C43 becomes BBC A. Sandy Heath ArqA therefore moves to C31 a week before BBC A starts at Sutton Coldfield, and ArqA moves to C67 (freed by ArqB moving to C48) a week before the remaining changes at SC.
If the two aerials are linked together with a diplexer, to put the signals on one cable, you may find that it only includes Group A channels (21-35) from Sandy Heath, and only Group B and above channels (37-68) from Sutton Coldfield. This means you won't get the commercial muxes from Sandy Heath when everything's complete (you might get ArqA when it's on C31). However, they have the same content at all English transmitters anyway.
I hope that's, um, clear?
| link to this comment |
Michelle: Check that your TV is not on the list of equipment that can't handle a split NIT at http://www.digitaluk.co.uk/splitnit . Most of these should have been picked up when the channels moved around about 18 months ago, though.
Otherwise, see Freeview reception has changed? | ukfree.tv - independent free digital TV advice . (RG47SH)
| link to this comment |
Tony Steel: I note that some of the same frequencies are in use at Sandy Heath, which has just begun switchover, but will still be used for low power services until September. Could be that something's been misconfigured or changed prematurely at that site.
| link to this comment |
Mr S M Davies: I suggest you send a suggestion to Humax! They've generally been willing to enhance their equipment in the past - as I said, the PVR-9200T didn't originally record from the buffer. Freeview didn't even have Series Link features when I bought the box in 2006 (I think it was), and the PVR-9200T has been upgraded to complete Freeview+ support.
Do check you already have the latest firmware -
Welcome to HUMAX [UK]
- though I don't see any reference to this in the release notes. The box should have auto-updated to this version already as it's been broadcast repeatedly on the engineering channel, although some boxes have to be in standby to auto-update. (RG47SH)
| link to this comment |
Mr M Brooks: You said before you were having picture break-up on channels on this multiplex. Try retuning it after 10:45pm or before 9:15am, the times you said last week that you got a good picture.
I'm not sure why you were prompted to retune, there were no changes at this transmitter on that date. There were switchover changes at Nottingham, Waltham, and Sandy Heath and its relays, but they're right over the other side of the country.
| link to this comment |
Friday 1 April 2011 3:16PM
Reading
Incidentally Arqiva have recently submitted planning applications to install solar panels and batteries at some sites, to reduce the grid power required and possibly sell some power back to the grid. Most of their sites are in the open and with few surrounding buildings, and are already an eyesore so adding solar panels isn't going to make it worse!