My main viewing equipment in the lounge is a Panasonic Vieira TV plumbed via HDMI cables to a Toshiba HD set top box with hard drive recording capability.
Just lately (last 10 days or so) around 18.00hrs any channel I watch on the TV above Channel 5 is so badly pixellated it's unwatchable (low channel quality reception), so I watch those channels through the Toshiba unit with no issues at all (I can watch one channel while recording another on the set top box).
I've tried retuning the TV several times with no improvement. Connections are set as:-

Aerial socket (in) to set top box and aerial (out) from set top box to TV.

Now the baffling bit. In the bedroom I have a Panasonic 22" TV taking signal direct from aerial via a splitter i.e. the same aerial as the main set up, and I have no issues on that TV at all

I guess I could get on hands & knees to disconnect the aerial from the set top box and connect direct to the TV and see what happens but am likely to end up in traction for a week.

Clues, anyone?

Mick, @Newportnobby
while in no way claiming to be a TV engineer, the first thought that springs to mind is ...
is something "smart" upgrading at that time, and causing the problem ?

our tv , off hand don't know the make / model / serial number but decides if you are watching one channel for to long to ask you if you want to switch off 

usually at a point when something interesting is happening.

doesn't matter if you are watching tv, or dvds, the thing has a mind of it's own.

Is it an active splitter or a passive splitter? Ie does it have power?

Quote from: Malc on June 17, 2021, 01:56:07 PM
Is it an active splitter or a passive splitter? Ie does it have power?

seems to have the power to annoy Mick 

Try replacing the cable between the set-top box and the TV (or at least give it a wiggle).

If that doesn't work then consider an splitter so the TV and set-top box get a direct feed - worth trying a passive one first.

Steven B.

Quote from: Malc on June 17, 2021, 01:56:07 PM
Is it an active splitter or a passive splitter? Ie does it have power?

Passive splitter fitted at the aerial end rather than further down to cable, Malc.

Quote from: class37025 on June 17, 2021, 01:27:30 PM
Mick, @Newportnobby
while in no way claiming to be a TV engineer, the first thought that springs to mind is ...
is something "smart" upgrading at that time, and causing the problem ?

Like it's owner, it's not a smart TV, Alan. It's roughly 12 years old and is a plasma model. I've plumbed BT TV into it via a BT box and also a wee trick box letting me play stuff from flashdrives/SD cards on the TV. Problem free until about 10 days ago.

Anyone bought a new microwave or electrical gadget that they start using at 6pm?

I loved my old Panny plasma, brilliant TV but in the end I upgraded to a 4K smart tv.  The plasma was donated to relatives for their lodger's room. It's still going.

Quote from: ntpntpntp on June 17, 2021, 04:29:28 PM
Anyone bought a new microwave or electrical gadget that they start using at 6pm?

John P

One problem with passive splitters is that every time you use one, you halve the signal going to each cable. So if you add a second one, you will get a quarter of the signal.
Am I right in assuming you have an HDMI feed from the set top box to the TV. In which case you need to check the aerial connection between the TV and the box. It's all it can be unless the set top box has a fault, which is entirely possible.

Have you tried plugging the aerial that you currently have going into the set top box straight to the tv to see if this fixes the problem, if the outcome is that it works, that either means there is a problem with your cable between box and tv or there is a problem with the "aerial out" port of the box.

Quote from: JonMann on June 18, 2021, 11:19:53 AM
Have you tried plugging the aerial that you currently have going into the set top box straight to the tv to see if this fixes the problem, if the outcome is that it works, that either means there is a problem with your cable between box and tv or there is a problem with the "aerial out" port of the box.

See last but one line in the opening post, Jon, but thanks anyway.

@Steven B @Malc
It does tend towards a cable problem, doesn't it. Do HDMI cables deteriorate over time?
Looks like a hands & knees issue after all

Not saying it isn't a cable problem, although they are easy(ish) to troubleshoot and fix... but that wouldn't account for it happening at the same time each day, pretty sure cables although allowing the issue are responsible for faults at specific times of day?

I thought the problem was with the free to air reception. Ie the TV set via the aerial not via the HDMI. Generally HDMI cables are robust and if you can watch the TV via the Toshiba, the HDMI is OK. I suspect that short length of cable between the Toshiba and the TV set. It's easier to swap the feed going to the Toshiba to go to the TV to check. It could be that the RF amplifier out from the Toshiba is picking up interference from somewhere. Ie a PC or an unshielded motor. Could be from a little distance away.

On a similar vein, I got back from East Yorkshire yesterday teatime, and my son announced that there was something wrong with the TV, (LG48" LED 3D flatscreen).  The tv is blurry at the top and bottom of the screen, most noticable when the credits are rolling.  I've not seen this before but he was true to his word.  Time for a new tv methinks.
Then I noticed that the tv remote was out, we only ever use the Sky remote,  and on the tv remote is a 3D button, I pressed that, and hey presto, tv fixed.
Note to self, never trust your kids with your technology

I reckon I/we am/are overthinking the problem. As @Fardap says, if all works OK during the day then it going haywire at a similar (not exact) time in the evening suggests something local is interfering with the signal or there's work being done on the signal somewhere. Guess I'll have to live with it and see if it improves at a later date. It's not insurmountable, just  annoying.