All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.
Alex Smith: The Humax PVR-9300T is SD only. It has an HDMI output, but this is to make it easier to connect to newer TVs that don't have as many SCART sockets - it simply upscales the content.
The TV may not be compatible either. It has to support DVB-T2, not just DVB-T. "HD Ready" just means that it has enough pixels to display HD content from another source, and a supported way of connecting to that source.
I'd consider replacing the Humax PVR with an HD PVR. Look for the Freeview HD logo.
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laura: Check whether your box supports 8K mode. There's a list of some equipment that is known not to at http://www.digitaluk.co.u…ment . If it doesn't support 8K mode you'll lose all the remaining channels when switchover completes next Wednesday.
There are still some boxes around that have problems with the larger Network Information Table. This problem shows up when you retune, although you'd have had to not retune for more than two years now. Again, a partial list is at http://www.digitaluk.co.u…tnit .
Do make sure you do a full retune - also called factory reset, first-time installation, virgin mode or default setting. Some boxes even seem to need to have this done with the aerial unplugged to ensure they're completely cleared out before doing it again with the aerial connected. For information on your particular box, see TV Re-tune productmanuals .
If that doesn't explain it, you could have too much signal. If you're sharing a communal aerial, get the landlord or management agent to adjust the levels. If not, try unplugging any amplifiers or boosters that you have. If you don't, you might need to add an attenuator to reduce the levels.
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Dave Lindsay: I became aware of the SIP Regions through the preparation of the 600 MHz band auction (that will not now go ahead), as one of the requirements for Single Frequency Network operation is that the transmitters sharing a frequency are part of the same SIP region. (SIP = Service Insertion Point.) The most recent planning document for that is at http://stakeholders.ofcom….pdf , and the SIP regions are listed in Appendix 5 (p50).
Since this was published, the BBC have decided to move Whitehawk Hill from the South to the South East region, and so it can no longer be a part of the Rowridge SIP region, but ITV have decided to keep it as Meridian South rather than move it to South East, so Whitehawk Hill (plus its relays) is now a region of its own.
I don't know of anywhere that lists the descriptions that are actually broadcast, though.
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The Wakefield: If the problems started at the last retune/power up, chances are that the combined signal strength of all the services is now too large. If you have an amplifier or booster, try removing it or turning it down. If not, you should try adding an attenuator to reduce the overall signal levels.
If you're using an amplified splitter to feed more than one TV, consider replacing it with a passive splitter instead.
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Dave Lindsay: Yes, I mean C31-C37.
'What will it be used for?'
That's really the question.
The issue that has come up is that there is now pressure, mostly from other countries, to release C48-C60 for mobile phone use. This range of frequencies ('700 MHz band') has already been released for LTE in the USA and Japan. Countries without a developed wired telephone and broadband network are interested in also using it, but at the moment it's not permitted anywhere in ITU Region 1 (Europe, Middle East and Africa).
Making mobile phone/wireless broadband 'co-primary' with broadcasting has now officially been put on the agenda for the next World Radiocommunications conference, scheduled for 2015. This was one of the last decisions at WRC12 in February. Ofcom have responded by consulting on what the future of UHF spectrum is. The consultation is framed very much on the idea of clearing the channels for wireless data.
Clearly there are a lot of transmitters using the 700 MHz band, and Mendip is one of the major ones. If this happens, *all* Mendip muxes would have to move somewhere. Thanks to the clearances at DSO, there is a gap from C31-C38 but that's only 8 channels and we have to clear 12. So a complete replan may be on the cards.
DVB-T is now quite old technology - 15 years, nearly - and we could get greater capacity per multiplex with DVB-T2, and also reduced bitrates (for the same resolution and picture quality) with MPEG-4 AVC/H.264 rather than MPEG-2. It would be possible to get the same number of channels into fewer muxes with DVB-T2, but of course everyone would have to get a Freeview HD box to replace their old box, or to add to their non-compatible TV. HD gear is selling quite well but it'll be a few years before it's near saturation and DVB-T could be switched off.
Ofcom's consultation is at Ofcom | Securing long term benefits from scarce spectrum resources - A strategy for UHF bands IV and V and Arqiva's high-level thoughts on how to replan are at http://stakeholders.ofcom….pdf .
The extra three muxes are still listed as a possibility, but the chances are we wouldn't be able to secure international clearance to do it - our neighbours generally only have 8 layers or fewer, and us seeking to replan our eight (which includes cleared channels at many locations, so really six) to nine won't be popular.
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Dacr11: After switchover, you should be able to get the UK PSB multiplexes from Gortnageeragh relay. Digital UK also predict a good service from Divis.
The Saorview coverage checker indicates that Ballymena should get overspill coverage from Clermont Carn in the Republic, once the aerial restrictions are removed after 24 October. The NI mini-mux is only supposed to fill in places where the real Saorview transmitters can't reach, which is why it is only going to transmit from a few transmitters and at relatively low power.
The power levels are not directly comparable between the NIMM and the UK PSB or Saorview services, because the NIMM will use a much more robust mode.
You will also need a Freeview HD receiver to receive the NIMM service, as it will be broadcast using DVB-T2, not the older DVB-T.
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There are some coverage maps in the Republic's Competition Authority's review statement. (The TCA were required to review the joint venture between RT and TG4, as both sell advertising.)
See http://www.tca.ie/images/….pdf , annex 1 and 3 specifically.
Ronan o dwyer: Analogue switch-off on the island of Ireland is not until 24 October. All four services are still broadcasting from Three Rock, RT One on C29, RT Two on C33, TV3 on C35 and TG4 on C55, all at 25 kW. Three Rock broadcasts the first Saorview multiplex on C54 at 63 kW, quite an increment when digital services are usually considered equivalent at one-fifth to one-tenth the power of analogue!
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Eddie: It's likely the problem is due to the power increases at sites that have already switched over.
Hastings Mux 2, A and B use the same frequencies as Rowridge, which is now transmitting at effectively double the old power, and on vertical polarization as well as horizontal - before it only used horizontal polarization.
Hastings Mux D is on the same channel as Whitehawk Hill BBC A, again effectively double the old power.
It's likely that there's nothing you can do until Hastings switches over in June.
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Steve Cheshire: Do check whether the aerial is pointing to Olivers' Mount. It could alternatively be pointing to Bilsdale, where the predicted service is very weak.
Even if pointing to Olivers' Mount, the box could be picking up a weak signal from Bilsdale or Belmont rather than the wanted service. See Digital Region Overlap on how to resolve overlap problems.
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Wednesday 11 April 2012 4:50PM
Ben Ward: The problem is that the relay transmitters retransmit the exact same datastream that they receive, it can't be subdivided. In fact to save costs, there are actually only 27 or so sets of Service Information, with even some main transmitters sharing the same information.
Therefore, a few years ago, the region descriptions changed from being the main transmitter in the Service Information region to being a rough geographical area. All of Mendip's relays, including the line-fed full Freeview transmitters at Bristol Ilchester Crescent and Bristol Kings Weston Hill, are simply described as 'West'. It was felt this was less confusing than signalling 'Mendip' when it might not be.
You can find the users of a specific channel by clicking the channel number in any post that mentions one, or in the list of pre/post-switchover channel numbers on a transmitter page - that gives you a map. It shows the pre-switchover state unless you clicked a channel in the 'After {switchover date} section. Or, you can go to Find a Freeview transmitter by frequency | ukfree.tv - independent free digital TV advice and click channel numbers to search.