Thanks to all who took the time to reply.
As suggested I have connected the booster signal with the 12v amplifier.
I get a frosty connection with only 2 or 3 channels. No digital connection.
The tv unit is a new one from Tesco. Technika 19" tv.dvd. Its actually the 3rd one. I purchased a Technika 15" tv/dvd for £120 and the screen was faulty, no picture but lines horizontal and vertical. I replaced it with a new one 19"for £130, added £10 and I thought it was a better bargain. This one got a picture but the image was pixilated. Returned it for this new one. Now, no digital reception but only frosty analogue. Hmmm. Dvd is great.
I always received analogue on my other analogue tv, this is the first time that I have, in theory, been able to receive digital. I know the aerial received analogue but can an AVTEX aerial only receive analogue and not digital. It says that it should on the box.
GJB, if the programmes play and not cd/dvd, sounds like your cd/dvd is duff.
I will try the unit in a friends motorhome. I am waiting for delivery of a 12v to mains adapter for the tv. He has a good aerial. If no digital, then back to tesco.
The unit really does look good. Maybe I've got part of a suspect batch.
Will keep you posted