All posts by Michael Perry
Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.
Rob
Very pleased that your efforts have resolved the problems. Glad those of us contributing to this site have been able to give you enough clues to get it sorted out at last.
The experience does show that not all problems are due to either transmitter faults or your own equipment so the process of investigation and elimination can be lengthy. It's often quite difficult to work out what might be happening when we are at some remote point and can't see for ourselves. Your descriptions clearly helped.
Congratulations.
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Mr Scott
Remember that the programme numbers used on a TV set are only used to assist viewers to select a particular service. The are often referred to as 'Logical Programme Numbers' for the very reason of avoiding confusion between the actual transmitting frequency (the UHF channel number) used to deliver a particular multiplex of programmes and the number you select on the TV. (A multiplex will contain the information for several programmes at the same time, see the listing for the different transmitters to what services are carried by each multiplex.) There are channels from 21 to 60 used for terrestrial TV broadcasting in the UK and the large number of transmitters are allocated a set on channels to use. The original intention had been to keep the channels used within a particular aerial group so that only one was needed. Nowadays, that is in the process of changing so that Ofcom could make more of the UHF spectrum available for other uses, such as mobile phones. There are discussions on-going about how that should be implemented, if at all, and hence what channels should be used by which transmitter, but there will not be much information available until the plan is agreed, if it is, and it is then likely that a further re-allocation of channels will be needed.
Note that Freeview main transmitter will use at least 6 channels, but that some are gaining further services requiring the addition of one or two extra channels. Many of the smaller transmitters only provide a Freeview 'Light' service containing just the PSB services like BBC and ITV, but often none of the purely commercial services, such as QVC, etc.
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Steve
Not everyone can get WiFi, not everyone can get DTV, not everyone can get satellite, not everyone has internet.
So as it is essential for everyone to be able to receive emergency broadcasts then we need s multiple system whereby if one delivery method is unavailable then others may well succeed.
And there are already lots of people making waves about the proliferation of RF in the 2.4 GHz band that is used for WiFi, despite the fact that the whole country, well very nearly, has been 'bathed' in RF at higher power for the last 40-odd years from the UHF television transmitters plus the numerous radio sources such as Droitwich broadcasting on 198 kHz (was originally 200 kHz) at quite high erp.
Public Service Broadcasting (PSB) is required to provide services over at least 98% of the population, meaning they have to find ways to reach some of the more difficult locations because people chose to live there.
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Briantist:
If BBC1HD moves to one of the newer non-regional Muxes, then wouldn't that create a disincentive so people are less likely to buy HD equipment as many prefer the regional nature of news and locally sourced programmes? Such services would only be available on SD services it would seem.
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MikeB
Not everyone has equipment capable of showing HD services and not everyone will want to pay out in these hard economic times for new equipment, applying the well tested and trusted adage of "If it ain't broke, don't fix it".
Many people will either not bother to use that service or set their recording equipment so they can view programmes when they want - much as they do now.
Others will of course want to use the service sometimes and may already have HD capable (not just 'HD Ready') equipment or intend to replace existing equipment anyway.
Seems very little gain overall.
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All
I know of four households, mine included that have Sky+, Freeview PVR and a Video Recorder all connected up and capable of recording and playing back programmes at a convenient time. A VHS can record for up to 4 hours (or 8 if you can stand the much poorer quality of LP mode!), a good Freeview PVR can record a good many hours of SD (and rather less in HD, higher bit rate) and a recent Sky+ box can do around 160 hours in SD. So we have a huge amount of available recording time (useful for holidays), or we can opt to keep especially interesting programmes. I know of few homes that don't have some form of recording facility but many would like it but can't afford the extra fees for Sky+ and only have a Freeview TV set with no recording facility. One problem is that people were not encouraged to keep their existing video recorders despite the fact that they can be set up with suitable leads (usually SCART) to take the received programme signals from the Freeview or Sky box, thereby giving them a 'free' recording facility with equipment they already knew how to use.
An analogue video recorder will only give basic resolution but Sky+HD and FreeviewHD PVRs can give decent pictures with an HD capable TV set and HDMI connections. And there are various converter 'gadgets' available to feed a VHS SCART output into an HDMI input!
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Corin
That's not the point. Viewers want to watch the programmes and not worry about resolution. The change from 405 B&W to 625 PAL had definite benefits, it was in colour and that was a major driver for the sale/rental of colour TV sets in those days.
Many people don't worry about whether, or by how much HD is 'better' compared to SD, see Ian's response above.
But if people can use their existing equipment to view and/or record the programmes they want then there is little incentive for them toi buy new and expensive equipment, only the opportunist viewer who scans the programmes just to find if there is something of interest to them.
And I'm not sure your figures are correct. Surely it is 720 line vs 1080 line horizontal definition with commensurate horizontal number of pixels. Still not as good as the 1250/100 we were using experimentally in the Eureka95 research group.
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Rural broadband is poor, as has been pointed out earlier. I am 4.7 km by wire from our local exchange that only has 20CN equipment and we generally get 2.5 Mbps, sometimes less and rarely more. Evenings, when many want to watch TV programmes is far worse due to contention and traffic volume issues - stuttering is the order of the day. So I try to use my Sky+HD box connected by Ethernet to the router and let that download programmes before viewing them. It's a pain to have to wait, sometimes for longer than the programme pasts because of the slow broadband - but at least it is better than the old 56kbps dial-up!
But the urban-based policy makers clearly fail to realise that rural broadband will never be as fast as urban broadband can be and the 'headline' speeds are rarely attainable - which is why Ofcom and ASA are in discussion with providers about misleading advertising. If BDUK completes (big if it seems) then rural broadband will have barely improved in many areas due to distances involved. And the project is not due to be completed until around 2019 at the earliest and may be running rather later than that! I'll not hold my breath!
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Wednesday 19 February 2014 7:54PM
Briantist
It is the experience of years that not all locations are able to receive RF transmissions due to mainly terrain limitation but also buildings, etc. The 0.2% who were unable to get direct reception of any television service are the more remote rural locations that will not be getting any form of internet connectivity and do not benefit from satellite as they are unable to aim a dish at the 'birds' - again largely due to local or nearby terrain, such as mountains. So when you say "are usually rural and suitable for satellite reception" you are not taking into account the many years experience of such places. The most difficult ones are not able to get satellite, nor terrestrial transmissions at UHF (and often VHF is difficult) and are too far 'out of town' to have any foreseeable chance of getting anywhere near decent internet speeds. A friend lives in Snowdonia and doesn't get Freeview, nor VHF radio and has an internet connection that runs at 64kbps at best! They are too far away from their 'local' exchange for anything better! They read a lot of books though!
Unfortunately, Ofcom seem keen to move all 'television' away from RF transmission onto internet services around 2025-2035. But the point I was making is that such an idea has numerous pitfalls and some are, as yet, insurmountable.