All posts by Michael Perry
Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.
Briantist:
Please see How to get BT Sport with BT | Help | BT.com Help which is on the BT Sports website. The secoond question down asks if you can get BT Sport if you don't live in a fibre area and the third option states:
With BT broadband
All BT Broadband customers can watch online at btsport.com and download the app to watch on their smartphone and tablet, at no extra charge.
That appears to be suggesting that ADSL customers with BT Internet (as oppposed to BT Infinity) can indeed get BT Sport.
It also states:
On the BT Sport App or on btsport.com
You can watch the action on your PC or Mac, or on your smartphone or tablet using the BT Sport App. You need a BT ID to access the BT Sport App and watch online. If you don't have a BT ID yet, you can sign up to My BT now.
That also suggests that BT Sport can be viewed without having to have BT Infinity. I suspect that the actual throughput speed (as opposed to the sync speed) needs to be adequate to provide a jitter-free experience.
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Alastair:
Which direction is your current aerial pointing? Plympton is South East of your location, see the Reception map, and it uses channels in the 40s/50s so a group K might be better than a Group W. If you are aiming at Caradon Hill then a Group A or Group K should suit.
Group W aerials are designated as Wide Band, suggesting they cover channels 21 to 68. But they are not so good in the lower channels (Caradon Hill?).
It is hoped that only 4G transmissions might affect only some Freeview services and hopefully only some in the higher channels, those closer to Channel 60. It does not appear that 4G will be available in you area as yet, so it is somewhat unlikely that you will be affected and it might only affect some Plympton services - if at all. If you are likely to be affected then @800 will send you 1 free filter that should resolve the possible problems. Fit it between your aerial and the first piece of equipment. 4G is not due to start until 29th August at the earliest, and then only in 20 selected major cities.
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John:
It is not the same service as the original Oracle, Ceefax or Teletext services that were available on the analogue TV transmissions.
I know of no equipment that has any facility to make the text service display 'full screen' as the format is determined by the broadcaster.
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MikeB et al:
DAB as a digital technique suffers the same limitations as any system that samples an analogue signal and tries to reproduce the analogue original. DAB has frequency range limitations that are narrower than FM radio. CD audio recordings have a similar limitation, effectively because of the sampling rate. The effect is to not reproduce the upper frequencies that form the tonal qualities of the sound heard. Compare a CD recording of a pipe organ with that of the same organ recorded by a good analogue technique and then compare with the live rendition! Having sung in choirs and choral societies for over 50 years, I know which I prefer. (I'm also an electronics engineer.)
DAB has problems as some have experienced, just as some have had trouble with Freeview digital transmissions.
Not all DAB radios have a VHF FM capability, two of mine don't but one does. The FM signal where I live is more reliable and clearer than DAB.
DAB+ would have been preferable but that will not happen now - too much investment in DAB.
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In addition to what Michael (above) says, digital transmission is more energy expensive and involves a significant delay.
A digital transmitter consumes more electrical energy to operate to give the same coverage area. Likewise, a digital receiver uses more electrical energy to power the more complex signal processing circuitry required to produce sound and/or vision.
The delay comes about because of the need to convert analogue signals from microphones into a digital format by sampling, then delaying the vision signal produced by a CCD camera so the sound and vision are 'in sync' with each other. Plus there is a propagation delay in the system bringing the signals to your local transmitter and finally in the preparation of that signal for final transmission. The delay can be detected by listening to the 'pips' on Radio 4 at 8 AM, on a DAB or Freeview tuned to R4 the delay is about 4-5 seconds. The VHF FM transmission is the more accurate but even that has a small delay (less than 1 second usually).
4G is only about mobile communications, but some manufacturer(s) just may find a market for other equipments for use in the home, in a similar way to the market for Internet 'Radios' that do not use RF transmission at all.
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It is perhaps worth bearing in mind that the hearing range of the human ear is not all that matters. Listening to a pipe organ through either an analogue or digital recording medium reduces the overall range of frequencies conveyed to the ear. A typical CD will limit the reproduced frequency range to approximately half the sampling rate, commonly 44.1 KHz so the limit becomes about 22 KHz. A very good analogue recording may reproduce frequencies up to around 30 KHz on good equipment. A 'live' performance of the pipe organ contains fundamental frequencies above 100 KHz (measured with a spectrum analyser) plus several 'overtones'. The ear cannot hear the actual sounds at that end of the audio spectrum - but the listener can detect the 'shaping' effect on the sound heard as a difference in tonal perception. Often, when listening to pipe organ music on any digital medium I miss the 'breathiness' typical of a pipe organ that is not reproduced by most audio equipment, hence I prefer live performances - my personal choice.
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Briantist:
I have sung with choirs and choral societies since the age of 11 (57 years now!) and there is a distinct difference in the audible experience of a live concert and anything recorded. The best recording system I am aware of, and heard, is a direct cut Deutsche Gramaphon vinyl recording where the groove was cut directly into the surface of the disc, rather than being pressed as with a 'standard' vinyl record. Of course you had to use really good quality HiFi equipment to get the full effect on playback. The discs are very expensive so quite unusual and rather unique. They are no longer made, sadly for HiFi buffs.
The point is that whilst the human ear does not hear fundementals above around 30 KHz for young people, and substantially less as we get older, the experience of the tonal qualities of the sound are shaped by the overtones that we do not directly hear. Imagine you see a square wave on an oscilloscope, you can't hear the 'attack' but can see it on the waveform, the square wave being made up of numerous upper harmonics. An audio signal can have a similar 'attack' front but the ear cannot pick up the harmonics that cause the sharpness but the sensation of the suddenness of the start is perceived if the overtones or harmonics are present, but if they are not there (as they are above the Nyquist frequency for the reproduction system) then there is some loss of fidelity. Many tests have been made on the hearing and perception of musicians as compared to non-musicians, the results are interesting in that many people do not appear to hear the same as a musician does - or so it is said.
For my part, I can tell the difference between performing with live music and with recorded music, I personally prefer live instruments and dislike many CDs because of the lack of 'presence' in the reproduced sound.
(My background is with electronics, including radio, TV, Video, Audio recording systems, Satellite systems and communications electronics, backed up with higher degrees in electronics and physics. Plus experience with EDA systems when working in an international software company).
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Briantist:
I remember listening to Schools Radio between 10 and 11 AM in the later fifties. At my school, the two upper years gathered together in the main hall/gym and listened to several interesting programmes, some were dramas and some of historical interest. We didn't have a TV set in the school, those came later. Incidentally, Radio Rentals Contracts used to provide larger screen TVs to schools and we service engineers had to maintain them and often found the problems were 'finger trouble'!
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Just a 'sanity check' question from someone who has been in the TV industry since the late fifties. We see a number of questions suggesting they have a 'booster' as part of the signal feed, but is it really an aerial amplifier or is it a powered splitter?
In the analogue days, very few people needed an aerial amplifier and it was always mounted as close to the aerial as possible. But many seem to be saying their 'booster' is in the loft! And some seem to be suggesting that it 'splits' the signal 2, 3 or more ways which suggests, to me at least, that it may actually be a splitter that has some built in amplification to overcome the inherent losses of dividing the incoming signal to feed several outputs.
As we all now know, having too strong a digital signal can be as bad as having too weak a signal, so are some people using an amplifier when it is not needed?
We could also ask about the '4G' perception, considering that the first three areas only went live in the 800 MHz band on August 29th (in parts of London, Leeds and Bradford I think) while the EE '4G' is in the 1800 MHz band so way out of band to cause DTV problems.
Food for thought?
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Thursday 22 August 2013 7:42PM
Hi Biantist:
I'm a BT Internet ADSL customer and they tried to sell me the BT Sports package but when they looked at the speed provided by their line feeding my very rural home they admitted it needed to be at least 5.6 Mbps (we're lucky to get 2.5!) with no mention of any infrastructure requirements. I can only go by what they tell me. Clearly, we won't be getting FTTC (nor FTTH/P) anytime soon, it's only just reached the main town 17 miles away!
Personally, I would not have taken the package anyway as we are not fans of almost all the sports they are showing, especially commercial football.