BBC 1 and BBC2 disappeared from my TV

Kapkirk

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Turned on TV tonight and no BBC1 or BBC2, tried a re-tune but still not there. HD is there on 101 and 102 though. Does that mean the non HD ch's have gone now?
Panasonic HZ2000 TV.
 
Turned on TV tonight and no BBC1 or BBC2, tried a re-tune but still not there. HD is there on 101 and 102 though. Does that mean the non HD ch's have gone now?
Panasonic HZ2000 TV.
No, they certainly have not gone, nor is there any prospect of them going for a good while.

What it means is that some issue is preventing you from receiving the signal, possibly due to interference resulting from the present hot weather. If you had not retuned, the signals may well have returned in a few hours, but now you will have to recheck at intervals.

It is an oft repeated advice on forum sites that the very last thing you should do on losing signals is to retune.
 
Hmm, that is weird, tonight they were back and I didnt do a thing. It wasn't in interference thing either, the actual ch numbers had completely vanished from the TV and my channels started from 03, ch's 1 and 2 were just not there, but tonight they were.
 
Location always helps in diagnosing TV reception issues and likelihood of interference from other transmitters.

Noting that such interference is quoted as a %age of time and often only occurs around dawn and dusk... making accurate diagnosis more difficult.

Detailed transmitter information for industry professionals has a prediction tool.

Modern TVs have an ability to auto-retune / add and remove channels (unless the feature is deliberately disabled) and might account for the behaviour seen?
 
Location always helps in diagnosing TV reception issues and likelihood of interference from other transmitters.

Noting that such interference is quoted as a %age of time and often only occurs around dawn and dusk... making accurate diagnosis more difficult.

Detailed transmitter information for industry professionals has a prediction tool.

Modern TVs have an ability to auto-retune / add and remove channels (unless the feature is deliberately disabled) and might account for the behaviour seen?
I am really puzzled as to what is going on.
I live in a building with a communal aerial system (facing Crystal Palace) and for the last 15 months (since getting my new Panasonic TV) every now and then the picture would just go off for a few seconds and come on again, I assumed this was a signal issue with the communal aerial system. I looked at the data error thing while in the tuning menu of the tv and saw that every now and then the signal was dropping out and back in again.
So I decided to put a small aerial of my own up outside my window facing Crystal Palace to see if it was my TV or their aerial system and the problem "seemed" to have gone away for a while but the problem is back again.
Yesterday BBC1 and 2 completely disappeared, today they are back but NOW BBC 3 and 4 and some other ch's had no signal.
All I did to get them back was to twist the aerial plug in the TV aerial socket and they all came back again this evening. Now this is a little odd because I noticed I did the same thing a few weeks ago and the signal came back again then so I decided to chop the end off the coax cable and re-do the coax plug fresh to eliminate the coax and plug. BUT this seems to be happening whether I use "my" TV aerial or the Communal Aerial, so now I am wondering if there is a bad connection inside the TV aerial socket even though the coax plug fits the socket tightly.
I have previously read somewhere that Panasonic TV's have weak aerial sockets . This intermittent fault is driving me nuts as I can't seems to nail it down.
I am in Harlow and am on high ground with clear line of sight to the horizon and the TX. I believe
there "is" a 5G mast on the roof of our building but I spoke to 2 of my neighbours in the building who said they are not having any problems with TV reception. So is the fault with my TV or something else?
 
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You'd have to be pretty unlucky to get a dodgy aerial socket on a relatively new TV but it is a possibility, I guess. Sockets can get loose over time, but I've only ever seen that on much older TVs, which have been repeatedly been moved and therefore disconnected/reconnected often.

The fact that you seem to be experiencing the same issues with both the communal system and your own aerial implies that the fault is either with the TV itself or there is a general reception issue, which could possibly be weather-related. That's presuming that each method uses entirely different cables/fly-leads though, so as to rule them out.

If your neighbours say they aren't having problems, it's possible they maybe haven't noticed or are simply not watching the same channels (so watching in HD rather than SD, for example). Also bear in mind that TVs from different manufacturers will have different tolerances in terms of signal strength - it may be that your building receives a poor signal which their TVs have less of a problem with.

What signal strengths are you getting ? You can check on a Panasonic by selecting 'Signal Condition' in the Freeview tuning menu. Have a look at the values for channels you receive without issues as well as the channels you're having problems with (when you are actually getting them, obviously !)

It might be worth replacing the wall coax outlet if it looks old and getting new coax cable fly-leads (or making up your own) just so you can be sure of ruling them out.
 
Communal aerial systems are often over-amplified and that can lead to tuner overload. But Harlow is far enough from CP to make this relatively unlikely on a properly set up and maintained system.

Harlow Post Office CM20 1JD has decent enough predictions with a slight possibility of occasional enhanced propagation interference. <=1% of time
Also shows good reception from Sandy Heath. Plus Sudbury and Hertford relay get in.
YOUR predictions will differ, of course.

Wolfbane: CP is diffracted, not line of sight, and only 52dBuV/m at 10 metres; Sandy is also diffracted and 46dbuV/m. The CP number is sufficient for a low gain aerial to work outside; but overload would be very unlikely - unless a masthead amplifier is involved.

Communal systems (if large enough number of users) should, ideally, be using channelised (filtered) amps for each multiplex to avoid amplifying unwanted transmitters' signals. Similarly they should use double screened cabling to avoid any potential direct cable pickup.

Mobile masts interference: check out Restore TV | TV Signal Interference | TV Filters With COM7 closing the communal system owners should remove any ch 55 amp for that (if applicable) and consider fitting a low pass filter to the aerial and amplifier input to ensure all 5G and LTE signals are eliminated.

I'd agree that all your cables should be checked and rechecked, though.

A likely 'interference' source could be hdmi leads; that might vary depending on what the hdmi devices are doing (even when nominally in standby). A loose TV plug may allow more in than one firmly seated. Separation and better screened cables can help.

Latest engineering works and warnings | Help receiving TV and radio isn't currently warning of any weather-related interference issues (last time was March).
 
Communal aerial systems are often over-amplified and that can lead to tuner overload. But Harlow is far enough from CP to make this relatively unlikely on a properly set up and maintained system.

Harlow Post Office CM20 1JD has decent enough predictions with a slight possibility of occasional enhanced propagation interference. <=1% of time
Also shows good reception from Sandy Heath. Plus Sudbury and Hertford relay get in.
YOUR predictions will differ, of course.

Wolfbane: CP is diffracted, not line of sight, and only 52dBuV/m at 10 metres; Sandy is also diffracted and 46dbuV/m. The CP number is sufficient for a low gain aerial to work outside; but overload would be very unlikely - unless a masthead amplifier is involved.

Communal systems (if large enough number of users) should, ideally, be using channelised (filtered) amps for each multiplex to avoid amplifying unwanted transmitters' signals. Similarly they should use double screened cabling to avoid any potential direct cable pickup.

Mobile masts interference: check out Restore TV | TV Signal Interference | TV Filters With COM7 closing the communal system owners should remove any ch 55 amp for that (if applicable) and consider fitting a low pass filter to the aerial and amplifier input to ensure all 5G and LTE signals are eliminated.

I'd agree that all your cables should be checked and rechecked, though.

A likely 'interference' source could be hdmi leads; that might vary depending on what the hdmi devices are doing (even when nominally in standby). A loose TV plug may allow more in than one firmly seated. Separation and better screened cables can help.

Latest engineering works and warnings | Help receiving TV and radio isn't currently warning of any weather-related interference issues (last time was March).
Hi thanks both of you for your replies, there is some pretty technical info there.

Originally I was using the communal system and do believe it is possibly over amplified which I thought may be causing issues, I used 2 x 6 dB in line attenuators in the wall socket but the signal strength still remained at 100% and the issues still remained so it seems there might be too much gain on their system.

I installed a small LOG Periodic (I had laying around) on the outer wall (I am approx 30 meters high) via 4 metres of COAX no amplification straight to TV.
According to the Panasonic Signal strength indicator I am getting 100% quality and 97% signal strength +- 3% across all ch's, no data errors.
Today I used a different piece of COAX and new connectors and rewired outside aerial so I will see how things go in the coming weeks.
 
LP +6dB CP @30m agl 57dBuV/m (still diffracted) -3 db cable terminations = 60dBuV --- the ideal being between 45 and 65 dBuV at the TV = perfect.

My Panny TV showed 10/10 for signals before and after digital switchover when there was a 10x power increase (+10 dB), because it measures after the auto gain control and error correction circuits. They seem to have changed that, and use %age on yours (much more useful for diagnostic purposes). I have one in the bedroom that is similar for metering purposes.

Best wishes for reliable reception now.
 
LP +6dB CP @30m agl 57dBuV/m (still diffracted) -3 db cable terminations = 60dBuV --- the ideal being between 45 and 65 dBuV at the TV = perfect.

My Panny TV showed 10/10 for signals before and after digital switchover when there was a 10x power increase (+10 dB), because it measures after the auto gain control and error correction circuits. They seem to have changed that, and use %age on yours (much more useful for diagnostic purposes). I have one in the bedroom that is similar for metering purposes.

Best wishes for reliable reception now.
I don't have a proper signal meter so have no idea if the signal from the mini LOG is enough, probably isn't really but it should be ok for temporary diagnosis purposes, ch 22 and 35 are borderline which is to be expected with this type of aerial I suppose, but I cannot risk putting up anything larger as my landlord will have a hissy fit.
What was really concerning me was the TV picture constantly turning on and off when the signal went away and came back every few seconds, don't think it's doing the TV any favours so I needed to do something about it. It has been perfect today but I feel pretty sure I will have to wiggle the aerial plug again in a few days when the signal goes away again (I lose a few channels and signal strength goes right down) as that seems to be the norm lately.
I do need to know if its a fault with the TV or aerial so I can get John Lewis to repair the TV if necessary.
 
I don't have a proper signal meter so have no idea if the signal from the mini LOG is enough, probably isn't really but it should be ok for temporary diagnosis purposes, ch 22 and 35 are borderline which is to be expected with this type of aerial I suppose, but I cannot risk putting up anything larger as my landlord will have a hissy fit.
That log will be fine. Perfect in fact if the predicted numbers at your location are similar to those for the (near random) postcode I used.

But you said all channels were received at 94-100% signal (97+/- 3) and that should be fine. In fact you could probably insert one of your -6dB attenuators in line - but not plugged direct into the TV's input socket due to weight/strain of the aerial cable on a 'lever' effect! - and still have enough signal.
Frequency ch 35 is the local TV mux and is much lower power (34 vs 200 kW erp) but uses a more robust modulation method to make easier reception; but you may suffer from weather related interference on that frequency much more than the others.

What was really concerning me was the TV picture constantly turning on and off when the signal went away and came back every few seconds, don't think it's doing the TV any favours so I needed to do something about it.
That won't harm the TV in any way whatsoever. If the TV isn't wall-mounted I'd be having a good look at the TV aerial socket to see if anything can be gently 'adjusted' to improve the grip on centre pin and/or outer of the plug. Especially of the plug feels loo se at all. Also try to remove any significant aerial cable weight from said connection (Panny TV usually have cable management tie points for cable routing to assist with that) to reduce any chance of the TV plug moving due to such a weight.

Double-check you have made the plugs properly - How to wire a Belling-Lee connector is the best way - but the soldering bit is a skill to far for most people.
Wiring up plugs, aerials and wall plates - A.T.V. Poles, Brackets, Clamps & Aerials has an alternative that is almost as good and easier to d-i-y.
 
Thanks for taking the time and all the advise, I'll keep an eye on it and let you know what happens.
 
Least technically you won't have to pay the tv licence anymore :laugh:
That's a rather nonsensical remark. The current licence fee applies to all television reception in the UK not solely that from the BBC. But I expect you really knew that.
 

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