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All posts by Michael Perry

Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.


Brian Wright:
The transmitted HD signals are all of 1980x1080 resolution. The electronics in the receiver interpolate that to 'fill in' the non-transmitted pixels available on the screen. So a single pixel at 1920x1080 becomes the equivalent of four to give 3840x2160 resolution (roughly speaking, it 'averages' between the pixels above and below as well as those to the left and right, so generating 'new' pixels to 'fill in' the ones not transmitted). If the receiver software design and implementation is good enough you should see what appears a good highly detailed image, but it is an interpretation generated from an originally lower resolution. You don't loose anything and the software can't 'invent' something that is not in the original, that's why they use interpolation algorithms.
Interpolation is a very widely used method of regenerating lost or missing image information and has been used for many years.

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Bernard:
If the coaxial sockets are connected to a UHF aerial system, then yes you could. But bear in mind that it could well be a communal system feed all the apartments in the development. The same is likely to be true of the satellite feeds, they are often fed via a distribution system and it is now common practice to provide two F type sockets to allow for Sky+ HD, etc.
The managing agents should be able to clarify what the sockets provide.

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John Dyas
Weather doesn't have to be 'extreme' to cause reception problems. The most common cause is a high pressure area causing a temperature inversion (warm air below cold air instead of the other way) and that creates conditions whereby RF signals travel further than usual, so we get French TV, etc. It doesn't even have to be warm weather here for it to happen either!

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IMHO, and based on 50 years experience within the TV manufacturing/servicing industries, the key for viewers is whether they can enjoy watching the programme content without any picture or sound artifacts spoiling their enjoyment. It is, therefore, somewhat subjective as to whether people prefer SD or HD or 625PAL, etc. It is for technicians and engineers to provide an enjoyable viewing experience. We can do nothing about content, that's up to BBC, ITV, Sky, etc.
If a viewer feels the need to comment on picture quality issues then there is a problem, but as we've seen on this and other websites most people don't care *how* it happens as long as it gives them the pleasure they expect.

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The fact that some French services are being received unusually means there is probably some temperature inversion or tropospheric lift causing poor or loss of Freeview reception

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Full technical details of Freeview
Thursday 12 December 2013 7:59PM

Nigel Love
It *has* happened before, quite often actually. There is nothing you can do about a natural physical phenomenon. Don't try retuning your TV else you may well lose all your services!

To all others having problems in the South, East and South East, just wait and be patient for the high pressure area to move away, then reception should be back to normal - unless you have wrongly retuned at the wrong time.

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Humax FOXSAT-HD freesat HD | Freesat
Thursday 12 December 2013 8:05PM

Re Skew
It is not always 7 degrees! Depends on where the receiving site is and which satellite is wanted.

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Mr Fowler:
Using the VHF input is a real problem. The signals you are want to use are *UHF* so will not pass through a VHF filtered input properly.

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Andre:
Not the BBC's fault either! You pay for a licence for permission to operate a broadcast receiving device, your TV set.
It is likely the problem is due to high pressure system near the SE of the UK. Do not attempt a retune else you may lose all services.

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Heathfield (East Sussex, England) transmitter
Friday 13 December 2013 8:36PM

There is a moral in many of the stories here about loss of Freeview programmes, multiple retunes leading to further loss.
It is that you should only retune as a matter of *last* resort after all other checks fail. That mean you need to make sure your connections are good and that there is not 'temperature inversion' conditions as is being seen currently over much of the south, south east and east of the country as far north as the Yorkshire coast.
Likewise, if you are using Sky and the box states you have lost signal, just wait a few minutes or try selecting a different programme. This is usually caused by a loss of the uplink signal to the satellite.

So in all cases, patience is a real virtue.

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