Blinking Dave

BillioBillio Member Posts: 9
Anyone have any ideas what is happening? When tuned to DAVE channel 19 the picture momentarily blinks every minute or so, apparently at random.
ONLY ON DAVE. All other channels inc Dave+ are perfect. The box is an old-ish DTR-2100. I have tried cutting down the signal strength, which is otherwise 100% (from a home distributor amp). The lowest I can get with 20db attenuation is around 62%, at which point "signal quality" starts to drop, but all channels still work as before, including Blinking Dave.
BTW he (Dave) does not blink if connected to the TV tuner directly... HELP

I have seen the problem reported before.

Comments

  • 1Welshman1Welshman Member Posts: 21
    my yesterday channel blinks it does it all the time , but during the very hot weather it moved to dave and then when it cooled down it reappeared on yesterday 
  • Tim CTim C Member, Super User Posts: 614 ✭✭
    Signal strength should ideally be in the 80-90% range otherwise the tuners can get overloaded.
  • LukеLukе Member Posts: 78
    edited 22 October 2022, 9:37PM
    Tim C said:
    Signal strength should ideally be in the 80-90% range otherwise the tuners can get overloaded.
    That was pre an update in 2017
    Roy said:
    Signal Strength in NextGen has been rebased, and should also now be around 100%, like Quality.
    Although I'm not quite sure it happened with the first version of NextGen. I think it happened in one of the updates either side of the 2017 initial NextGen update.



  • joneshjonesh Member, Super User Posts: 1,679 ✭✭✭
    Lukе said:
    Tim C said:
    Signal strength should ideally be in the 80-90% range otherwise the tuners can get overloaded.
    That was pre an update in 2017
    Roy said:
    Signal Strength in NextGen has been rebased, and should also now be around 100%, like Quality.
    Although I'm not quite sure it happened with the first version of NextGen. I think it happened in one of the updates either side of the 2017 initial NextGen update.
     If the signal quality is consistently 100%, it doesn't matter what the signal strength reading is.
  • LukеLukе Member Posts: 78
    jonesh said:
    Lukе said:
    Tim C said:
    Signal strength should ideally be in the 80-90% range otherwise the tuners can get overloaded.
    That was pre an update in 2017
    Roy said:
    Signal Strength in NextGen has been rebased, and should also now be around 100%, like Quality.
    Although I'm not quite sure it happened with the first version of NextGen. I think it happened in one of the updates either side of the 2017 initial NextGen update.
     If the signal quality is consistently 100%, it doesn't matter what the signal strength reading is.
    Of course, but I was just replying to the other replies.

  • joneshjonesh Member, Super User Posts: 1,679 ✭✭✭
    Lukе said:
    jonesh said:
    Lukе said:
    Tim C said:
    Signal strength should ideally be in the 80-90% range otherwise the tuners can get overloaded.
    That was pre an update in 2017
    Roy said:
    Signal Strength in NextGen has been rebased, and should also now be around 100%, like Quality.
    Although I'm not quite sure it happened with the first version of NextGen. I think it happened in one of the updates either side of the 2017 initial NextGen update.
     If the signal quality is consistently 100%, it doesn't matter what the signal strength reading is.
    Of course, but I was just replying to the other replies.
    So was I @Luke.
    I quoted your post because it came across as reinforcing the idea that 100% signal strength is a target to be aimed for.
    Our box works perfectly well with a signal strength of 60-65%.
  • BillioBillio Member Posts: 9
    Not really sure how old my box is, maybe 6 years, could be more. In any case BLINKING DAVE happens on signal strength 60-100% (variable 20db attenuator) and 100% quality.
    Sometimes it stops blinking late evening.
    Seems to me the Dave frequency is being spiked by transient noise, momentarily overloading the tuner? I shall invest in a better fly lead and re-check the socket.
    Any more ideas, anyone?

    DTR-T2100 originally from BT.
  • joneshjonesh Member, Super User Posts: 1,679 ✭✭✭
    edited 25 October 2022, 7:00PM
    Billio said:
    Not really sure how old my box is, maybe 6 years, could be more. In any case BLINKING DAVE happens on signal strength 60-100% (variable 20db attenuator) and 100% quality.
    Sometimes it stops blinking late evening.
    Seems to me the Dave frequency is being spiked by transient noise, momentarily overloading the tuner? I shall invest in a better fly lead and re-check the socket.
    Any more ideas, anyone?

    DTR-T2100 originally from BT.
    A bit tedious, but have you tried monitoring the Dave signal quality in Settings to see if it drops momentarily?
    Attenuating a boosted signal isn't ideal. Is it possible to lower the boost on your distributor amp?
    You could try temporarily disconnecting the amp altogether. You might find that you don't need it.
    If your box still works, it's age is unlikely to be the problem. If our box makes it until next March it will be ten years old.
    Try a different fly lead, but don't bother investing in one of the expensive ones.
  • BillioBillio Member Posts: 9
    @jonesh Thank you. I have tried most of your suggestions, but getting at the distribution amp in the loft and so on is something I don't fancy: it is 23 years old (a lot younger than me!) and I don't want to mess with it.

    I replaced the HDMI, which made no difference. I replaced the coax fly lead with a better quality and remade the socket: no difference. The signal as reported by the box does not spike.
    Three things of note.
    1)  I replaced the fly lead with a longer cheapo one, so I could avoid all other cabling (particularly the HDMI). I can get now get 100% quality at about 70% signal strength, but waggling/moving the coax nearer the other wires drops the quality on Dave, which doesn't happen on the other channels. It suggests there is some UHF interference at or around the Dave MUX frequency, which originates near the coax. 

    2) Our other two tv's upstairs directly on old coax work perfectly on all channels.

    3) Dave has now stopped fighting me and is no longer BLINKING DAVE!
    This happened overnight, spontaneously!
    Time will tell, but just maybe the problem was/is at Emley Moor...

    IDEAS ANYONE??

  • joneshjonesh Member, Super User Posts: 1,679 ✭✭✭
    Billio said:
    @jonesh Thank you. I have tried most of your suggestions, but getting at the distribution amp in the loft and so on is something I don't fancy: it is 23 years old (a lot younger than me!) and I don't want to mess with it.

    I replaced the HDMI, which made no difference. I replaced the coax fly lead with a better quality and remade the socket: no difference. The signal as reported by the box does not spike.
    Three things of note.
    1)  I replaced the fly lead with a longer cheapo one, so I could avoid all other cabling (particularly the HDMI). I can get now get 100% quality at about 70% signal strength, but waggling/moving the coax nearer the other wires drops the quality on Dave, which doesn't happen on the other channels. It suggests there is some UHF interference at or around the Dave MUX frequency, which originates near the coax. 

    2) Our other two tv's upstairs directly on old coax work perfectly on all channels.

    3) Dave has now stopped fighting me and is no longer BLINKING DAVE!
    This happened overnight, spontaneously!
    Time will tell, but just maybe the problem was/is at Emley Moor...

    IDEAS ANYONE??
    The most likely source of interference is your HDMI cable or cables. They are notorious generators of unwanted RF radiation.
    If the problem returns, try a different HDMI lead.
  • RoyRoy Member, Super User Posts: 17,591 ✭✭✭
    edited 30 October 2022, 7:32AM
    @Billio

    DAVE is on Mux ARQ A, as are Sky Arts, Really, E4 Extra, and others, listed here:-
    https://www.freeview.co.uk/corporate/platform-management/channel-listings-industry-professionals

    If you think it is a Mux problem, see if any of the ARQ A channels are also a blinking nuisance. 
    Though the reports of it moving to Yesterday, which is on ARQ B, are more suggestive of an issue with the family of UK TV channels, than the Mux.

    Personally, I would incline to a flylead of satellite-grade coax, dressed nowhere near any HDMI cables.
    ‘Have nothing in your houses that you do not know to be useful, or believe to be beautiful’ Wm Morris
  • BillioBillio Member Posts: 9
    Thanks everyone. I still get Blinking Dave syndrome from time to time, but it is acceptable.
    Being late to the UHF debate, I find it almost magical that signals can be jumping around and so much dependent on cable quality/routing.
     
    Still, we accept without question that these signals travel over distances and through walls, in a Quantum kind of way. 
    Time will tell.

  • BillioBillio Member Posts: 9
    Blinking Dave was bad again tonight. Sooo…
    I have wrapped the coax and the HDMI separately in regular tinfoil, for about 300mm up to the back of the Youview box, and for an hour or so there has been no more blinking…
    Maybe coincidence, but it chimes well with many other posts re HDMI  to coax interference. :)
  • BillioBillio Member Posts: 9
    @jonesh see my comments re wrapping the HDMI and the coax with tinfoil, at the back of the Youview box.
    Two hours of watching Dave, and the picture was faultless. 
    Seems like HDMI  and coax into the same box is always risky.
    Thank you for your help.
  • RoyRoy Member, Super User Posts: 17,591 ✭✭✭
    @Billio

    Certainly badly shielded and/or poorly grounded cables can be troublesome.

    Are you using the HDMI cable that came with the YouView box, or some other HDMI cable you have? If so, how is it rated?
    ‘Have nothing in your houses that you do not know to be useful, or believe to be beautiful’ Wm Morris
  • joneshjonesh Member, Super User Posts: 1,679 ✭✭✭
    Billio said:
    @jonesh see my comments re wrapping the HDMI and the coax with tinfoil, at the back of the Youview box.
    Two hours of watching Dave, and the picture was faultless. 
    Seems like HDMI  and coax into the same box is always risky.
    Thank you for your help.
    The designers of terrestrial TV receivers put the aerial socket a distance away from the HDMI sockets. With TV boxes getting smaller, the distance can be short.
  • BillioBillio Member Posts: 9
    The tinfoil ploy was a failure. I think basically the problem goes away on its own in the late evening!
    The HDMI is new, from eBay, supposedly good quality…
    The coax and the HDMI are now well clear of each other, and the blinking is minimal after about 6pm.
    To be continued…

  • joneshjonesh Member, Super User Posts: 1,679 ✭✭✭
    edited 1 November 2022, 7:54PM
    Billio said:
    The tinfoil ploy was a failure. I think basically the problem goes away on its own in the late evening!
    The HDMI is new, from eBay, supposedly good quality…
    The coax and the HDMI are now well clear of each other, and the blinking is minimal after about 6pm.
    To be continued…
    Oh dear. 
    Are there any electrical devices nearby that go off in the late evening? It doesn't need to be near your Youview box. Just somewhere in the vicinity of the run of your aerial cable.

    edit: If the aerial cable from your loft is the same age as your distribution amp, it probably needs to be upgraded to (say) CT100. Use F-type connectors except for the last flylead
  • BillioBillio Member Posts: 9
    Me again. Have put the Youview box upstairs, feeding a different TV, and with no internet connection. All has been perfect for several days. Dave picture is fine, but if you lift the hood the Dave signal quality is shown as around 75%, ( as are all on the same MUX) but all the others are all 100%. 
    Also Dave signal quality varies a lot if you move the flylead around.
    I guess I will track it down before they find Lord Lucan! 
    Thanks guys for the ideas and help.
  • RoyRoy Member, Super User Posts: 17,591 ✭✭✭
    edited 5 November 2022, 4:38PM
    @Billio

    If moving the flylead varies the quality, then either you are moving it in and out of the ambit of another cable that is radiating, or the flylead itself has issues.

    Maybe check the terminations at each plug end, ensure they are properly made, with no possibility of intermittent partial shorts or partial open circuits?
    ‘Have nothing in your houses that you do not know to be useful, or believe to be beautiful’ Wm Morris
  • BillioBillio Member Posts: 9
    Blinking Dave has left the building!
    fitted new flylead. Fitted new HDMI which has in-built ferrite suppressors (found it still in its wrapper: it could be the one that came with the Youview box years ago). I think it was the HDMI that solved the problem, plus routing the coax and HDMI  in opposite directions.
    So it looks as if the 20 year-old distribution amp in the loft, 25 year-old aerial, and the house co-ax are stile sound. Also the Youview T2100 box seems to perform as it should.
    I noticed previously that the quality of the Dave signal was variable, as measured by the box. We shall see.  


  • joneshjonesh Member, Super User Posts: 1,679 ✭✭✭
    Billio said:
    I guess I will track it down before they find Lord Lucan!

    Billio said:
    Blinking Dave has left the building!
    I think it was the HDMI that solved the problem, plus routing the coax and HDMI  in opposite directions.
    Just in time @Billio. :)
    A chap claims that he might have found Lord Lucan.
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