Yet another TV reception/aerial question. Poor pic quality.

[randers]

Hi guys. I looked for any answers to this on other threads but didn't find it, so many apologies if it's been asked before and I stupidly failed to see it.

My son has a new TV and a rented flat. His new tv pic is poor (soft images) yet the TV is a good one. I tried my tv in his flat with the same result, so the assumption is that it's his feed from the rooftop aerial.
Have tried better aerial cable from wall socket to TV - no great improvement.
Have tried an indoor amplifying aerial (just a little Maplin's job - sorry!) - no improvement.
The bizarre thing is that the picture is good on HD channels but not on ordinary (is that "low definition" now?).
He can't do anything about the rooftop aerial as that's the landlord's.
So I have a couple of questions for the lad - why would HD channel pics be ok but non-HD channel ones be poor if they're both coming from the same aerial? And is there anything he can do to improve the quality of the picture he's getting? Thanks, I appreciate any help you're able to give.
In case it affects anything, he's in Leicester and someone suggested that Leicester gets generally poor TV reception, but I hadn't heard that before so can't vouch for it being true.

 

[Sam Gangee]

Is this a Freeview TV without an external Freeview receiver?
It's always a good idea to divulge model numbers and manufacturer.

However, in this case it's not necessary because a digital picture is "all or nothing". With sufficient signal, the picture is as good as it can be (limited only by the TV itself). With insufficient signal the picture will be breaking up or completely blank.

So either what you are seeing is a normal SD picture or else the TV is faulty or incorrectly set up.

 

[randers]

Thanks Sam Gangee. Yes, silly of me, it's a Samsung UE40h5500. The Freeview receiver is internal to the tv.

So if I understand correctly what you're telling me, the fact it's reproducing something on HD channels means it's getting plenty of signal, therefore the doubts are about the TV or the tv setup?

 

[Lucid]

The E. Midlands area gets an overlap of transmissions from several areas. It may be that on an auto tune the TV is picking up the wrong transmitters and storing those first. This is more of a problem with the standard definition channels because there's more of them compared to the HD channels.

The other issue is with auto tune itself. Depending on the set, it doesn't start from scratch each time. Rather, it refreshes the channel list it already knows about. This is good for adding new channels within a mux. But it's useless if you need the TV to find new muxes.

Mux/muxes: The old analogue TV transmissions carried one channel per frequency number. Digital carries a group of channels; a multiplex or 'mux' for short. For example, the Waltham transmitter has all the HD channels on ch31 and ch58. Tuning just those two channel numbers gets all the HD services.

If you know what transmitter the aerial is pointing at then you can do a manual tune so that the TV is only receiving signals from the local transmitter. Have a look at the UKFreeTV web site. Here the link for the main Leicester transmitter (Waltham) but bear in mind that there are smaller repeated transmitters too. UKFee.TV

 

[Sam Gangee]

So if I understand correctly what you're telling me, the fact it's reproducing something on HD channels means it's getting plenty of signal, therefore the doubts are about the TV or the tv setup?

Correct.