All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.
Sally: The factors that makes them slightly harder to receive are that the receiver has to distinguish between more different levels (four rather than two), and more different phases (16 rather than 8).
Anything that reduces the signal level available, or increases the noise or interference level, will increase the difficulty of reception. Reception in the UK is usually interference-limited: that is, the limit of the coverage area is down to interference from other stations, rather than due to obstructions reducing the available signal level, or the inherent thermal noise generated by the receiver's electronics. (Obstructions are largely a problem when the interfering signals are *not* obstructed.) For C33 (ArqB's temporary home), the major source of interference in the UK is Crystal Palace BBC Two, though there are also some relays in the south-east such as Eastbourne. There may also be interfering stations in France.
Because BBC Two is the first to shut down at Crystal Palace, you may see an improvement on Rowridge ArqB's reliability from 4 April.
As far as Digital UK's postcode checker is concerned, only Mux D has converted to ArqB at Rowridge; Mux C is still running in its pre-switchover mode.
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Tony: No, Crystal Palace's switchover (and therefore all its relays, of which Guildford is one) starts on Wednesday 4 April. Guildford stopping use of C41 is the pre-requisite for Hannington making full use of it. Nearly all switchover events happen on a Wednesday. Only SDN's restriction is lifted on the 4th, ArqA and ArqB will still be restricted until the 18th.
To remove the restriction, services need to be switched from the restricted antenna to the main antenna, which involves disconnecting and reconnecting. Guildford C41 is being released by multiplex 2, which is taking over the BBC low-power multiplex's channel for the two-week period between stage 1 and stage 2, so that has to move before Hannington's changes can start.
Digital UK only guarantee that the work will be done by 6am. There are no technical changes to the multiplexes' configuration, so you do NOT need to retune, unless you cannot get the channels at the moment.
It's likely that BBC Two analogue at Crystal Palace and relays will be shut down shortly after 12:20am if the schedule is similar to this week and next (the BBC like to shut down at a programme junction, rather than in the middle of a programme). BBC One may have already shut down as the programme junctions this week and next are at 12:05am.
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ALAN PEACHEY: I believe the Anglia East and West regions still split for a small amount of local news. At Watch Anglia Tonight | Anglia - ITV News , part 2 is labelled 'East'. (No sign of an online video for 'West'!) Otherwise, the difference is merely the advertising.
Anglia West is encrypted because it is on one of the pan-European beams on the Astra 2B satellite. If it was not encrypted, ITV would have to pay much more for broadcast rights for all of the *other* programmes, to cover the whole broadcast area. Anglia East is not encrypted because it is on the UK beam on Astra 1N, which is intended to only cover the British Isles and is much harder to receive elsewhere in Europe (a substantially larger dish is usually required, and the signal levels available outside the official footprint could change without notice, as happened earlier this year when services moved from Astra 2D to 1N).
Oddly, Anglia South is also free-to-air, even though ITV no longer sell advertising airtime for this subregion separately from the Anglia East subregion, and it has never had a separate news service. It is anticipated that ITV will shortly close some of these redundant services, which may make space for Anglia West to move to Astra 1N and go free-to-air. However, the space might alternatively be used to provide a +1 hour timeshift of the Anglia service, replacing (for Anglia viewers) the Meridian +1 service you currently get.
The regional variations on satellite are selected by the postcode that your viewing card is registered to, for Sky, or the postcode you entered in system setup for Freesat. You can still view an alternative version through Other Channels/Non-Freesat Channels. The region boundaries are roughly those of the terrestrial transmitters: Anglia West is the area covered by Sandy Heath and its relays, while Anglia East is the area covered by Tacolneston and its relays. (Anglia South was Sudbury and its relays, but Sudbury now just transmits the same as Tacolneston.) There's a map in ITV Media's Factsheet at http://www.itvmedia.co.uk….pdf .
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Bunbury: Sky Text moves from Mux D to ArqA at switchover. Because Rowridge hasn't fully switched to the final configurations, with Mux D having been replaced by ArqB, but Mux C not yet replaced by ArqA, Sky Text has fallen through the cracks. It'll be back on 18 April.
I can't recall, is there even a text-based news service on there any more? Last I remembered, Sky were using it to run interactive games along with Challenge.
BBC Red Button has exactly the same content as Ceefax (which is a waste, because Red Button has far more capacity). They're generated by the same system. Sometimes this is obvious, when a Red Button page doesn't render properly - I hope the BBC will soon change this to be primarily written for Red Button and Ceefax derived from that. [Usually, the Ceefax and Red Button content is the first four paragraphs of the online article, which is why online articles sometimes read strangely.]
You can still type page numbers to move to a specific page you want to read, or can scroll around and select an item to read. The only real differences are that you have to press Down to show the next screen of a longer story, or Up to scroll back up, and that the coloured buttons now operate other features rather than being context-sensitive jump keys.
In my view, manual scrolling is better than the automatic scrolling that inevitably left you waiting too long to see the next screenful, or took it away before you'd finished reading. Pressing Green gives you a shortcuts menu, but I can't remember if that's context-sensitive (i.e. shows you related pages) or whether it simply has the same list all the time.
The BBC do appear to have decided to use very large fonts, and only half the screen most of the time, which does mean that you have to scroll more to see the whole story, compared to the number of screens on Ceefax.
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ALAN PEACHEY: Astra 1N / Astra 2A / Astra 2B / Astra 2D / Eutelsat 28A (28.2°E) - All transmissions - frequencies - KingOfSat suggests that 11639 V would be a transponder on Eutelsat 28A (formerly Eurobird 1), though it shows the D10 transponder on 11642 MHz. It's listed as carrying occasional feeds, which may be what's happened here. Or, a broadcaster may have decided to rent that transponder, though Italian channels would be surprising on the 28.2°E cluster as they're nearly all in English, or Commonwealth languages targetting UK viewers. Or it could simply be a cock-up - it looks like Arqiva or BT are responsible for uplinking to its proper home on Hotbird 13B (located at 13°E). If it is simply a case of uplinking to the wrong place I'd expect the whole Hotbird 13B 10732 MHz transponder to be duplicated.
More about the channel at RTB Network ::: RTB City, RTB Virgilio, RTB Crypted, RTB Web & Televideo
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Richard Smallcalder: WARNING - Panasonic CRT IDTV problem with latest channel launches - Freeview - Digital Spy Forums has some information about this set. My suspicion is that it may not support 8K mode, or not without a firmware update. Contact Panasonic to see whether it is compatible, and whether a firmware update is available.
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metcalfe: AV1 and AV2 will be devices connected to the TV's AV1 and AV2 sockets. Check that whatever is plugged into AV1 is turned on.
If AV1 is an analogue video recorder then no, it won't receive anything over the air. You can still play back previously-recorded programmes. Some VCRs are able to record whatever programme you're watching, from the SCART connection. To record a different programme or do scheduled recordings, you could make the VCR record from a separate set-top box, again recording from the SCART connection, but this is quite difficult to set up. It's far easier to replace the VCR with a hard-disk-based Personal Video Recorder.
If there is nothing plugged into AV1, you shouldn't expect to see anything.
If there is something else plugged into AV1 and it's not displaying even when it's on and operating, try disconnecting the SCART cable and plugging it back in.
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David Brine: The specification on Sony's website says 'Digital Terrestrial Tuner (MPEG-2): YES', which makes me think that it isn't Freeview HD compatible. HD pictures are compressed with the newer MPEG-4 AVC/H.264 standard - they're also broadcast with the newer DVB-T2 standard, not DVB-T as the others are.
The user manual on the Samsung website is dated 5 June 2008, which is before the DVB-T2 specification was completed. The manual doesn't mention DVB-T or DVB-T2 at all, but my guess is that the design is too old to be compatible.
I don't think you have to remove the satellite dish connection to use the Freeview tuner on the Sony. You simply select Digital for Freeview, or Satellite for Freesat, from the Cross-Media Bar (XMB). You may find that picture quality is slightly better on Freesat even for those channels that are available in SD on both Freeview and Freesat. Just remember that the channel numbers are different on the two platforms (yes, Freesat numbers start at 101, rather than 1, but also the Freesat numbers aren't necessarily 100 plus the Freeview channel number).
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Pete: The signal strength is the same as it was, but they have changed the mode of Mux B so that it has enough capacity to even carry Sky Sports 1 & 2. This mode change is what has caused the problem, for some viewers on the edge of the previous coverage area.
Before Wednesday, the channels were carried (on a temporary basis, for regions yet to switch over) on the BBC's Mux B, but this has now changed to a completely incompatible mode in order to carry the HD channels. The 'matched' capacity had become available because the BBC shut down all the services that wouldn't fit after switchover, and squeezed some others into Mux 1. The permanent home was always going to be ArqB.
The main source of interference is probably Crystal Palace BBC Two, which will close on 4 April, so you may see some improvement then. After 18 April's retune, Rowridge ArqB will still be co-channel with Crystal Palace ArqB, but Rowridge will have had a power increase to 50 kW. If it's still a problem, you may want to consider switching the aerial to vertical polarization, which will broadcast at 200 kW.
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Wednesday 21 March 2012 10:20AM
Mike: C21 is the high-definition multiplex, and it broadcasts in a mode that is not compatible with SD boxes. You will only be able to pick it up on Freeview HD-branded equipment. A TV marked 'HD Ready' is not good enough, in the UK - that just means the TV *could* display HD pictures *if* they're provided by some other piece of equipment.