LG TV - HD works, standard channels pixelated.

Freedoddy

Novice Member
I've tried Google but to no avail. Our LG TV is about 9 months old. The HD channels all work fine...but the standard channels are ALL pixelated and breaking up. Signal test shows everything above 49dB and HD streaming services work perfectly over a 5G WiFi connection.

All I've seen on Google refers to standard channels being fine but issues with HD - generally down to poor signal strength.

This is the opposite. Does anyone have any idea what the problem could be please? 🙏
 

EndlessWaves

Distinguished Member
It could be signal strength if you're on a transmitter that broadcasts the HD channels at one end of the range and your aerial is only good for those frequencies.

Do the SD channels broadcast alongside the HD ones work ok? FreeSports (ch65) for example.

I'm guessing by 'pixellation' you're talking about glitching where pixels are the wrong colour rather than the picture looking like it's low resolution and made up of giant pixels.
 

Freedoddy

Novice Member
It could be signal strength if you're on a transmitter that broadcasts the HD channels at one end of the range and your aerial is only good for those frequencies.

Do the SD channels broadcast alongside the HD ones work ok? FreeSports (ch65) for example.

I'm guessing by 'pixellation' you're talking about glitching where pixels are the wrong colour rather than the picture looking like it's low resolution and made up of giant pixels.
Hi, thanks for your response.

I checked channel 65 and that works fine (noticed it's not classed as an HD channel).

All the channels worked fine up until a couple of weeks ago so I'm sure the antenna is suitable - what occurs to me at the minute is it may have been swung into a non-optimal direction by recent stormy weather perhaps?

By pixelated I mean this...
 

Freedoddy

Novice Member
See below
 

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mikej

Well-known Member
I checked channel 65 and that works fine (noticed it's not classed as an HD channel).
Freesports is an SD channel that is broadcast on the same 'mux' (COM7) as some of the other HD channels such as BBC News HD and BBC Four HD. COM7 is on UHF 55 and the irony there is that COM7 is the mux that many people (including myself) have problems with ! :D

This chart (courtesy of aerialsandtv.com) shows which aerial types are better suited to certain frequencies.

TV-aerial-gain-curves.jpg


With the exception of COM7 at UHF 55, all the other Freeview muxes are broadcast at lower frequencies (the Winter Hill transmitter, for example, uses the range 24-37) so if you had an aerial more suited to the higher frequencies and the PSB3/BBCB mux (which carries 1-5 in HD) was towards the upper end of the frequency range, then that might explain the behaviour you're seeing (stronger HD channels and the majority of SD channels suffering from pixelation).

A gust of wind that put your aerial slightly out of alignment and lowered the signal strength of all the frequencies received could have just put your SD channels into your TV's problematic range but a dodgy coax cable/connection/fly-lead could also be a possible cause. It might be worth swapping out the coax fly-lead and checking the aerial wall outlet is OK. Is your signal split between any other TVs in the house ?

If I was you, I would find out which transmitter I was on (the checker on this site might help if you're not sure) and see if you can identify what type of aerial you have by sight. Group C/D aerials have been obsolete for many years now but if it turns out to be a Group B or E aerial, then that might explain what you're experiencing and you might find that an alternative aerial type would now be more suitable to the frequencies currently in use and give better results. The checker on the site I just linked to will give the recommended aerial type for your location. A powered masthead or distribution amp (if you have multiple TV outlets) can also be an option in certain circumstances.
 
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