Tv Transmission Breakdown

[SmallTorque]

I know this is way off the topic of cars, but is anyone else experiencing breakdown of TV channels?

This is the third time in around two months it has happened here in the West of Scotland (Clyde area).

We personally do not have Sky, which I understand functioning OK. We are receiving nil on terrestrial channels (BBC and ITV) for last few hours and getting very frustrated about the whole thing. No info available anywhere that I can locate. Any TV engineers out there who can explain just what is happening?!

Thanks.

[Adie]

Atmospherics maybe a storm coming or something?? Or even a big fat bird sat on your aerial.. That happened to me once and ****** up all the channels :duh:

[SmallTorque]

Trouble is we don't have a roof aerial and the whole area seems to be affected. Happening regularly now and just wondered whether anyone else in the Clyde Valley experiencing similar failures. It's a calm night here and all programmes off for over four hours now. Doom and gloom!

[Mr Morse]

So...you have terrestrial TV thru a digital-compliant aeriel and a box?

Or what?

[SmallTorque]

I meant that we don't have an outside aerial that birds can perch on - the flats have a common aerial in loft.

Anyway, this break in transmission is affecting a wide local area, not just our set. And all the channels are still off this morning! Something very strange going on.

[alajota]

Alien Invasion

[lelandv]

Oddly enough, in our area, *SOME* of the digital channels have gone flaky in the past couple months.

We can no longer pick up Channel 5 at all. BBC is clear as a bell. Channel 4 is clear, but E4 has slightly weak signal so get the digital breaks from time to time.

Having said that, I think they have increased the power of the transmitter that we're receiving from since all channels were generally about 55% signal strength up until two months ago. Now BBC and Channel 4 are around 90% signal strength. E4 is still about 55%, and 5 is off the bottom end of the scale.

[Jiberjaber]

I would say it is likley to be tropo ducting given the recent weather conditions this may be leading to prolonged occurances of this which could cause certainly interferance.

Total elimination of the signal could be engineering works on your local transmitter.

Are you suffering the same loss with radio broadcasts as well?

BBC teletext has an engineering page on which shechduled maintenance is listed. Might be worth checking.

As a bit of back ground (ducting is not uncommon btw)

A less common, but often dramatic, form of tropo is called ducting or duct effect. This occurs when there is a defined, horizontal boundary between air masses having different densities. When a cool air mass is overlain by a warm air mass, as is the case along and near warm fronts and cold fronts, radio waves at VHF and UHF are reflected at the boundary if they strike it at a near-grazing angle from beneath (within the cooler air mass). Because radio waves are also reflected from the earth's surface, the result can be efficient propagation for hundreds or, in some cases, upwards of 1,000 miles, as the waves alternately bounce off the frontal boundary and the surface. Ducting can allow long-distance radio reception in the frequency-modulation (FM) broadcast band between 88 and 108 MHz.� It can also affect the lower VHF television channels if receiving antennas (rather than cable networks) are used.

Some more info and a little diagram here:

http://www.angelfire.com/sc/scannerpost/tropo.html

This may help as well:

http://grampiantv.scottishtv.colo.ednet.co...t.asp?page=s5_6

[lexus boy]

I would say I have no idea why it happens, but it used to in my old house just disappear on some channels for hours or even days