Loss of ITV signal in the evening

I am currently losing the signal to all ITV channels and BBC HD channels at about 18:30 every evening. The signal strength on the TV shows Signal Strength 0%, Bit Error Level 2000. At the same time, BBC 1 and 2 signals are at Signal strength 98%, Bit Error Level 0. I am not sure what time things get back to nermal but by the morning, all channels are back up to full strength.
My transmitter is Winter Hill and I have two aerials, a 48 element on the roof and a Log Periodic in the loft. I am using the internal Log Periodic at the moment while I rewire my roof aerial.
While I am writing this, my wife has just discovered that there is full signal strength on E4+1 but no signal on E4? Any help appreciated.

We have a similar problem that has steadily got worse. I've a feeling the connector/contact has deteriorated
near aerial end, coupled with cheapish aerial lead, should have silicon greased it when on installation. It might not be in your case but worth checking maybe.

You're using a Log Periodic, so that's lower gain than a typical Yagi in the upper half of the frequency range. You're using it inside the loft, so again that will reduce the signal level a bit because of it going through the roof. Add these aspects to the fine weather we're having at the moment and the fact that this problem is triggered at a certain time of the day and I'd say there's a fair chance that you've got some interference caused by tropospheric propagation.

Tropospheric what?

Basically, signals from distant transmitters (Emley Moor or Moel-y-Parc perhaps?) are reaching your home because the weather conditions are right for them to bounce off the underside of an atmospheric layer. There's more on this from the BBC web site.

The short answer is to either get the Log outside - it's a better long term bet than a typical wideband high-gain Yagi anyway since all the channels are getting pushed down to lower frequencies where the Yagis aren't that efficient.

I have not noticed tropo with Winter hill, in Suffolk it was common. If you are getting tropo not much you can do. It seems the aerials are placed at slightly different heights on the mast, and so you can get lower one, but loose upper one.

Some times you see smoke from a house go up and flatten out, where it flattens out hot and cold air meet and produce a radio mirror. So the radio ham or CB guy can talk for miles further than normal as the signal follows the inversion but go to top of a hill, and instead of going up and following inversion and coming down many miles away, it goes down and hits inversion then is refle Ted into space.

The cure is to use a higher frequency which can go through the inversion, in other word free Sat not freeview, this also means at midnight it does not switch off, or of course internet TV.

I have never noticed sporadic E with TV. I will guess as we don"t return all the time. In Suffolk we would get Dutch TV, their aerials are lower, however the sound and vision have a different gap so either listen or watch not both.

There are no 48 element aerials. 18 or 21 are about the limit. Someone has counted the elements 4 times and then lied.
Most likely you have a twelve element quad bay aerial.

ericmark said:

I have never noticed sporadic E with TV. I will guess as we don"t return all the time. In Suffolk we would get Dutch TV, their aerials are lower, however the sound and vision have a different gap so either listen or watch not both.

Click to expand...

Sporadic E is common with TV at VHF frequencies but not at UHF mostly used now. There have been reports of sporadic E reception from Eastern Europe this year.

Does a neighbour park a bus in line of site every evening ?