All posts by Michael Perry
Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.Vince:
Your are extremely close to the transmitter! It may be that your signal is just too strong for reliable reception. Could you check what the strength is on several channels, including any that are affected by the problem. The ideal strength is between 50% and 75% normally, any higher than that will cause apparent loss of signal as it's too strong for the tuner. The cooler atmosphere at night can sometimes cause changes in the transmission efficiency of the surrounding air.
The other point to check is whether there is any electrical equipment in the vicinity that come on or goes off at that time. Any warehouse, factory or office with such equipment can cause problems if there is a fault present.
You should also check whether you have any electrical equipment that comes on or goes off at that time, such as central heating controls, timers, etc.
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Nicolas:
I'm afraid it doesn't appear as if you are aware of the key points of good satellite reception. To receive the signals you need an LNB suited to the wanted signals with a reflector that is correctly shaped to focus the very weak signals into the LNB. A garage door is exactly the wrong shape to focus the signals onto the LNB. Parabolic reflectors are designed specifically to focus the signals correctly and avoid extraneous unwanted radiations from outside the area of interest, namely line of sight to the wanted satellite(s). A north facing garage door is looking in exactly the wrong direction for any geostationary satellites when viewed from the Northern Hemisphere, the satellite all being 'parked' in geostationary orbits above the Equator, which is south of the UK. The Astra satellites, used by Sky and Freesat, are roughly above East Africa so the dish needs to be aimed at that orbital position, so the azimuth of the dish is *not* 28 degrees east - you have to allow for your latitude and longitude as well as the exact satellite position.
Anybody can try anything if they know how safely.
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Nick:
The presence or absence of Al Jazeera does not define a Full Service transmitter. All transmitters carry all the PSB muxes and the Full Service ones carry many of the COM muxes. 'Lite' transmitters do not carry the COM services. Whether a particular transmitter carries any of the optional channels, like Al Jezeera, is entirely up to that particular broadcaster. If they don't want to be carried on any of the muxes allocated to Sudbury then they don't have to pay for it.
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walter:
I'm afraid you don't appear to had gathered the point. To watch *any* TV live you must have a TV license. It is not dependent on whether you watch BBC only or not. If you want to watch any of the Freeview services 'live on air' then you must have the license, which is a form of permit to operate the receiving equipment. That has been the case for more than fifty years.
At last, they propose to include those who watch TV programmes via a 'catch-up' service so they will be contributing to the production and transmission costs as well.
I don't agree that it is an 'archaic intrusion into our freedom of choice' as you can choose not to watch any TV if you so wish, or you can choose to watch whatever TV services available that you wish providing you pay towards the production/transmission costs and have a suitable licence to permit you to operate the equipment in that way. It's very like having to have a Road Fund Licence for your car, you can drive it without but you are not contributing to the maintenance of the roads, etc.
If you want to watch TV, then you must pay the licence.
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Steve:
To be able to offer any suggestions to resolve this issue we really need a full post code of where you live (or that of a very nearby shop or post office) so that the reception conditions for your local transmitter can be determined.
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As a general 'aside', most organisations these days don't publish as they used to do. All they do now is 'put in the public domain' by havimng the information available on a website but without telling anybody that it is there and where to find it. Governments and Councils are notorious for that failure. Example; the recent PCC elections, none of the candidates in the South West (to the best of my knowledge) ever properly publicised their 'manifesto' yet they expected the general public to vote for them! None sent out any election material by post nor delivered by handIt seems that 'those in positions of authority' assume that everyone else already knows where to find the information and that everyone has access to the internet - they are wrong on both counts. With the recent announcement by Government that those without internet access won't get it unless they specifically ask an ISP to provide it and they are very likely to charge exhorbitant sums for such provision.
(Note that part of my job, before retirement, was in Technical Publishing, so I do know something about proper publishing and know the difference between that and 'putting in the public domain', which is all they seem to do nowadays.
I wonder whether that may apply in this case of Channel 5 HD? Have they 'put it in the public domain' without telling anybody?
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James Watt:
That was correct several years ago but for the last 15 years or more many equipments have had adjustable modultaors that could be set between Ch21-68. The objective of such range was for the instances where the previously 'unused' channels (35-38) became occupied by a broadcasting service. That then meant that if the modulator could not be adjusted away from that range (as most older ones couldn't) then the user suffered interference from the modulator signal, either co-channel, adjacent channel or adjacent+2 - all of which are problematic for viewers.
Such adjacency is less of a problem with digitally encoded UHF TV transmissions as they carry error correction capabilities that were not suitable for analogue encoded UHF TV transmissions.
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Tim
Having previously lived near Chippenham, I am aware that most parts of the town do not need any amplification at all provided that a good quality aerial is being used, we used to have an 11 element Group C/D Yagi without amplification and had excellent reception. Generally, age does not matter as long as the condition of the terminals is good without any corrosion and the cable is in good condition.
I agree a good log-periodic will make the installation as future-proof as possible, bearing in mind that we do not know for certain what the channel allocation plans are much beyond 2020.
Note also that there is no such thing as a 'digital aerial' as all UHF aerials can receive the Freeview signals - they are standard RF signals carrying a modulation. That used to be in an analogue format but is now in a digital format - but the RF signal has not changed at all. The modulation format makes no difference to the ability of an aerial to receive the carrier signal.
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Saturday 7 May 2016 10:40AM
Trowbridge
Christopher Wilton:
Thanks for the post code, useful. It seems that your reception of the Arqa A Multiplex (also known as Com 5) is causing problems, but I assume that all the other services are as normal?
Com 5 carries several TV services, a look near the top of this page shows a number of programmes on that multiplex. Do you get any of these on Com 5? What is the signal strength on channel 24 and what is it on channels 21 and 27?
Sometimes a problem with the aerial feeder cables or connection can give rise to selective reception, seeming fine on some channels but poor on others. So a careful check that all the cables and connections are in good order would help. If in doubt, you can replace the flylead from the wall socket to the TV, they are inexpensive and are known to sometimes be the cause of problems.
Further advice depending on feedback.