All posts by Michael Perry
Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.
Vic:
Knowing the Esher area fairly well having worked from Tolworth, I suspect your 'old' outdoor aerial was faulty or the cabling from it to the TV set was. The signals from Crystal Palace should be received perfectly well by a good aerial system, so I would advise having a contractor examine your outdoor system and correct the faults found. An indoor aerial is not guaranteed to give reliable results.
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Dollasky:
This website is meant to be used for technical advice, not self-agrandisement.
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Barry Cornforth:
There are at least two possible ways to get Freeview, having a TV with it 'built-in' or by adding a Set Top Box that can receive Freeview.
The first means having a TV set that is designed to receive Freeview, preferably one that had HD built in and not just HD ready. The former have a DVB-T2 tuner to get all the available Freeview channels, the latter does not have such a tuner so can't get all the channels.
The second is an additional box, rather like a Sky box, and could have a recording capability as well. Good ones cost from about 50 without the record feature or from 120 upwards with the record capability.
In both cases you need a suitable aerial (not one labelled 'digital') for your location. It should ideally be professionally installed and covered by a guarantee for the work done.
Note that a 'smart TV' is one that can connect to the Internet, but that is not required to get Freeview as the signals are transmitted from ground-based stations. If you put your full post code into this site, you will get to see what transmitters cover your area and some indication of the reception possibilities.
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Den:
What you describe is typical of having too small a dish installed. A 'standard' Sky dish is typically only 35cm across and is just about adequate in the South East of England but is no good at all in the North of England or in Scotland, a larger dish is needed. A friend of mine in Inverness needs to use a 90cm dish!
What is happening is that atmospheric moisture (rain, fog, snow, etc.) absorbs some of the signal from the satellite to the point where it becomes too weak for good reception. A larger dish is less susceptible to such effects and will give a more reliable result.
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Den:
A Zone 1 dish is borderline in central England and poor further north. A Zone 2 would be far better. In Trowbridge I use a 65 cm dish and have no issues. I would advise at least that size for you location. Remember that for satellite reception, you very rarely get too much signal but it is not uncommon for people to have too little.
When I wrote the initial dish installation manuals for installers, when the first Astra satellite was due for launch, we had to calculate some complex mathematics to determine dish positioning and size for may different parts of the UK. The fact that Sky and Freesat now use digital encoding does not alter the need for sufficient signal to give reliable reception. In the analigue days you would get 'sparklies' which showed you had reception problems due to insufficient signal to noise ratio. Nowadays you get break up and drop out telling you the same.
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James Finlan:
Your post reveals the cause of your problems. 100% signal strength is too strong -especially for HD reception. Ideally you should aim for between 60 and 80% strength but as near 100% quality as is possible.
According to the data shown in the blue boxes below your posting, you should have a very strong signal - which may be too strong for good H|D reception. Search this website for 'too much of a good thing' and try what is suggested there.
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Vic:
When you mention a 'junction box' do you mean an active splitter, a passive splitter or just a join between three or more coaxial cables?
There may be faulty connections inside a 'junction box' and you should double check all joints and connectors are fitted proper. If you are using a passive splitter, with no power supply needed, are all the output cables connected to a TV set? If not, an unconnected cable can give rise to frequency selective reflections within the cable and/or impedence mismatch which can cause you type of problem. Aerials must be connected to a 75 Ohm load, adding a passive splitter with an unconnected cable will change that dramatically! So check that there are no breaks in any of the cables too.
Any aerial for Crystal Palace must be either a Group A type (but not a wide band one, they will not help you) or else a log-periodic (which are wide band coverage) and all with the rods horizontal.
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James Finlan:
I would suggest getting two, one rated at 3 dB and the other rated at 6 dB. Get the coaxial ones as they can be connected into your aerial cable very easily and can even be connected in series (one after the other). So when you get them, try putting the 3 dB attenuator in the lead first, but do not let it 'hang' on the aerial sockets, it's best to get a short aerial flylead whilst ordering the attenuators, flyleads are quite inexpensive. So you should end up with a flylead from the wall socket (if you have one), then the attenuator laying on the floor followed by the existing flylead going into the TV set aerial socket. (The reason for that is that aerial sockets are not very strong and can be distorted by the weight of an attenuator.) If the signal problems persist and the strength is still too high, swap the 3 dB attenuator for the 6 dB one. If that solve s the problems then you've won. If, however, there are still some problems you can add the two attenuators in series giving 9 dB attenuation. Hopefully that will bring your signal strength into the range acceptable to your tuner. If needs be, you can swap the attenuators for a 12 dB type to give even more reduction, but don't reduce it too much as that can then start affecting the channels that have been OK up until now.
In my experience from working in the domestic TV servicing industry until retirement, the variable types are often suspect quality.
Hope that helps?
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Joe Neal:
To be able to offer meaningful advice, we need to know what your local reception conditions are like. This is best done by you giving a full post code (or that of a very nearby shop or public building - within 100 yards) so we can see what the actual terrain and flora is like.
Whatever solution may be warranted, it is likely to involve a re-siting of your dish to where the local tree foliage is not a source of signal reduction or disruption.
It would help if we knew what sort of building you live in as there are rules about where you can mount a dish, especially if it is a building in multiple occupation.
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Tuesday 31 May 2016 7:04PM
Gordon Insley:
4G is transmitted only on channels above 60 and so will normally only affect signals in that band ro those very close to. That means channels 58, 59 and 60 could possibly be affected if, anbd only if, there is a 4G transmitter in the surrounding area. Channels from Sutton Coldfield are not affected by 4G as they are too low a frequency (channel number).