BT Youview box (DTRT2100) blocks 602Mhz, Disconnecting cures reception problems on freeview set

SageSage Posts: 5Member
edited 4 May 2018, 3:29PM in Discussion
Just a heads up for anyone with poor freeview reception, in case it is not a one off fault. 

Just disconnected my Youview box as I hardly use it since the HTML5 firmware installed, the TV had been plugged into the box's antenna out socket.

Connecting the antenna direct to the TV, my reception on channels that were currently breaking up or a complete loss have improved significantly. With the antenna connected through the box I get zero signal strength on UHF 37 (602000 khz) and reduced signal strength with zero signal quality on UHF 60 (786000 khz). Other Muxes I checked showed a small degradation in signal strength.


Tried it with the box's antenna out setting both on and off with exactly same results.

The Youview box had no reception on the same channels it affected on the TV and since new has frequently put up those annoying messages warning about poor reception on some channels when the atmospheric conditions were less than optimal.


Comments

  • RoyRoy Posts: 14,212Member ✭✭✭
    The antenna switch on the box should have no effect on the signal out when the box is On.

    Having said which, neither should the passthrough destroy part of the antenna signal.

    It sounds a bit as if your box has been faulty from new; I presume you have tried the various resets possible, to see if they make any improvement?
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • redchizredchiz Posts: 4,622Member ✭✭✭
    Or it could just be a **** cable between the two that was causing the issue?
  • redchizredchiz Posts: 4,622Member ✭✭✭
    Umm, sorry about using an apparently naughty word, a common synonym for poor which sounds like trappy.
  • VisionmanVisionman Posts: 8,886Member ✭✭✭
    It sounds like you have a faulty box or cable. As passing your aerial signal through your box to the TV shouldn't affect it. Whats your signal strength and quality?
  • RoyRoy Posts: 14,212Member ✭✭✭
    edited 4 May 2018, 9:53PM
    redchiz said:
    Umm, sorry about using an apparently naughty word, a common synonym for poor which sounds like trappy.
    Always a difficult one. I used it on the Sony forum, and it was dumped on; but the related emoji, taken from the forum options, slid right past them.

    But that was manually moderated; when I happened to use the expression ‘for the nonce’, instead of ‘for the time being’, the Lithium profanity detector took it quite the wrong way, and blanked out the apparently offending word  :D
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • joneshjonesh Posts: 1,187Member ✭✭✭
    edited 5 May 2018, 6:19PM

  • SageSage Posts: 5Member
    edited 5 May 2018, 12:31PM
    Visionman said:
    It sounds like you have a faulty box or cable. As passing your aerial signal through your box to the TV shouldn't affect it. Whats your signal strength and quality?
    The cable is fine, had the cable from the antenna plugged directly into the lead normally used to connect from the box's antenna out to the TV, so all the same leads were in use when comparing signal strength.

    When I tested it, signal strength on my TV's freeview tuner on  602,000 khz was 43% and Quality 100% with the box out of circuit, and with the box connected 0% & 0%. One of the other muxes I checked at the same time was 90% signal strength and Quality 100% direct, and the signal strength dropped by as much as 8% via the box's TV out, quality still 100%. The other mux that was less badly affected has slightly lower signal strength with the box disconnected, than the one on 602,000 khz.

    Prior to unplugging it, it hadn't occurred to me either that the Youview box's TV out might impact on reception on some frequencies, yet not on others, but  thinking about it, the box would need to amplify the signal, rather than using a passive pass through and I'd guess it is probably adding noise on some frequencies. 

    Odd that it should be UHF channel 37 that's affected the most, as I seem to recall that being used as the RF output channel for an 8 bit micro I once had - not that I would expect a youview box to have an analogue RF output :smiley:

  • RoyRoy Posts: 14,212Member ✭✭✭
    edited 5 May 2018, 4:04PM
    jonesh said:
     
    Look like somebody flushed your LooView :flushed:
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • joneshjonesh Posts: 1,187Member ✭✭✭
    It's back, emboldened by your LooView joke.

    I hesitate to go off-piste these days. There has been a bit of a sombre atmosphere about the Forum since NextGen was released.
  • redchizredchiz Posts: 4,622Member ✭✭✭
    Back on topic: I am confused now as to how the antenna was connected direct to TV, was this not in fact direct toTV??
  • RoyRoy Posts: 14,212Member ✭✭✭
    jonesh said:
    It's back, emboldened by your LooView joke.

    I hesitate to go off-piste these days. There has been a bit of a sombre atmosphere about the Forum since NextGen was released.
    I think NextGen left a lot of people piste-off  :p
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • joneshjonesh Posts: 1,187Member ✭✭✭
    edited 6 May 2018, 1:25PM
    Roy said:
    jonesh said:
    It's back, emboldened by your LooView joke.

    I hesitate to go off-piste these days. There has been a bit of a sombre atmosphere about the Forum since NextGen was released.
    I think NextGen left a lot of people piste-off  :p
    Not as piste-off as Thomas Crapper would have been if he had known that at some time in the future his name would be in common usage to suggest that something is of poor quality :/.

    Edit: I have been informed that the word sometimes used to suggest that something is of poor quality has no link to the name of sanitary engineer Thomas Crapper.
  • RoyRoy Posts: 14,212Member ✭✭✭
    edited 6 May 2018, 9:49AM
    redchiz said:
    Back on topic: I am confused now as to how the antenna was connected direct to TV, was this not in fact direct toTV??
    I’m confused by your question.

    All my TVs that work with a PVR, YouView or not, have the antenna connection going to the PVR, and then a second cable carrying the passed-through antenna signal from the PVR to the TV.

    It’s how we used to do it with VCRs.

    I know some zapper boxes don’t have the antenna out, but I would have thought your TalkTalk box did.

    In fact, I’m so confused, I think I must have misunderstood your question, though I can‘t see quite how  :/
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • redchizredchiz Posts: 4,622Member ✭✭✭
    OK, first of all Sage said he had a better picture on the TV with the aerial connected directly than passing through the YouView box. I queried if this might simply be the case of a poor RF cable between the two. 

    Sage then said: "The cable is fine, had the cable from the antenna plugged directly into the lead normally used to connect from the box's antenna out to the TV, so all the same leads were in use when comparing signal strength."

    Do you see my confusion now? Why would you need "all same the leads" if connecting directly to TV?

  • AnaglyptaAnaglypta Posts: 737Member ✭✭✭
    edited 6 May 2018, 12:19PM
    @redchiz
    Makes sense to me. @Sage was testing the YouView patch lead by connecting it directly to the antenna lead and then in to the TV.

    Having tested reception by connecting the antenna directly, (no problems) and then placing the patch lead in circuit, it would be immediately apparent if the patch lead was faulty.

    That's my interpretation of what Sage was doing.

    John.
    "Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity." - George S. Patton
  • redchizredchiz Posts: 4,622Member ✭✭✭
    That would be my interpretation now also, as far as one can tell, but not based on the opening post. If that had been said then I would not have wasted my time suggesting a cable issue.
  • RoyRoy Posts: 14,212Member ✭✭✭
    redchiz said:
    That would be my interpretation now also, as far as one can tell, but not based on the opening post. If that had been said then I would not have wasted my time suggesting a cable issue.
    Well, you asked as a supplementary question:-

    Or it could just be a **** cable between the two that was causing the issue?

    which Sage, in response to this, neatly eliminated as a possible issue by coupling the two cables together directly.

    I am always pleased when a suggestion I make is acted on, whether or not it leads to a resolution, or at least to the elimination of one or more possible causes of an issue.
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • redchizredchiz Posts: 4,622Member ✭✭✭
    Um, yes, but if he had explained himself more clearly in the first place there would have been no need. Or are you further interpreting that the third only happened after the second? Anyway, enough already!
  • RoyRoy Posts: 14,212Member ✭✭✭
    redchiz said:
    Um, yes, but if he had explained himself more clearly in the first place there would have been no need. Or are you further interpreting that the third only happened after the second? Anyway, enough already!
    Yes. Sage only tried your valuable diagnostic suggestion after you had suggested it.

    Which does leave us/him with a misbehaving YouView box, possibly broken internally, possibly just needing a reset of the appropriate severity, which is the next thing Sage should try.

    Assuming that he hasn’t already, and assuming that he is still with us.....


    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • SageSage Posts: 5Member
    edited 25 August 2018, 1:16PM
    I had already tested the cables before posting this thread, stating it was an issue with the box. 
    I only really posted because while I'd read some owners' reviews that this model doesn't perform well in areas of poorer reception; it hadn't occurred to me, so probably wouldn't to many others, that the pass through might also adversely affect reception on a TV tuner.

     I even made a fresh connection on my antenna lead using a new aerial plug to rule out corrosion on the plug/cable and also to rule out the remote possibility that a small amount of rain water might have got in the coax core (which had there been any (there wasn't) could have created a short at the plug that clears itself when the plug was higher up in the back of the telly).

    I retested my youview box today to see how it performed under a different signal strength, having left the box powered without an antenna connected.

    On UHF 37 (602000 khz) today with antenna directly connected to my telly, my TV reported  30% signal strength with 100% Signal Quality (about 10% lower strength than when I previously posted) and had a good solid reception with no break up.

    But connected via the youview box's antenna out the TV tuner's reported signal strength actually went up this time, mostly into the 40s, but jumping around occasionally (sometimes 20%, sometimes 0%), signal quality varied from 12 - 50%, and the picture on the same channel on that mux was blocky and breaking up.   

    I think my box just needs a stronger signal than I currently get on some muxes to mask the noise the tuner/amp  produces.

    Anyway, I intend to scrap the box once I viewed all the recordings on it, my brother showed me his terrestrial TV set-up using a tuner on an old PC and the guide was at least as good and software he's using looked better than both Youview and my freeview set.
       
  • SageSage Posts: 5Member
    edited 25 August 2018, 1:56PM
    I thought it might be worth updating this thread, since the freeview frequencies around here had changed, and the atmospheric conditions are currently better.


    After re-tuning the built in  freeview receiver on my TV, I connected up the Youview box to see how much of an effect it now has on the reception of my LG TV's tuner.

    This time, I saw no reduction in signal quality,  all muxes I checked reported 100%, and a small increase in signal strength on the mux with the weakest reception (from around 34 to 38%) on my TV's tuner, and no visible affect  at this time, to the reception on my TV's tuner.

    The box has not been reset, it is just the atmospheric conditions are better, and the frequencies that the various muxes are using have changed, which leaves me convinced it is an issue with the design of the tuner on the BT Youview box.



     
  • ukstevesuksteves Posts: 9Member
    edited 27 August 2018, 8:09PM
    We have a similar weird thing with our Humax YouView box.  Round here, COM7 and COM8 are broadcast at a stupidly low power level - and given we're 30 to 40 miles from the transmitter (Rowridge, Isle of Wight) picking them up becomes a real challenge.  Our YouView box can't receive COM7 or COM8 basically - which means we lose a load of HD channels.  

    Connected to the YouView box, via the loop through connector, is a Sony Bravia TV.  The Freeview tuner in the TV is able to pick up both COM7 and COM8 perfectly - with no picture breakup at all.  However, it only works whilst the YouView box is in standby.  The minute I bring it out of standby, the Sony TV loses the channels too.

    In my view, this proves that the YouView box is definitely introducing some kind of interference in to the signal whilst its not in standby mode - which is preventing the TV from picking up the weak signal.  We also have an older Huawei YouView box - I should get it out the cupboard and see if it behaves the same way.

    However - any thoughts?  Is there something I can tweak or disable in the settings that might help?

    Edited to add: Another weird thing.  The YouView box will record an HD channel broadcast on COM7 or COM8 perfectly too (e.g. Quest HD) - but only whilst the box is in standby.  The minute you bring it out of standby, it stops working. Most weird...
  • ukstevesuksteves Posts: 9Member
    OK - I've done some playing with the settings on the box.  COM7 and COM8 are broken only when the box is set to output at 1080p.  If I change the setting to 1080i or 720p, it all works perfectly.  Signal quality on the COM7 and COM8 channels jumps from zero to 70%! Might the problem be caused by interference through the HDMI lead?
  • RoyRoy Posts: 14,212Member ✭✭✭
    At a guess, you have the aerial lead from the YouView box to the TV tightly bound up with the HDMI cable from the box to the TV.

    You need to ensure that these two cables run as far away from each other as possible.

    If this improves things dramatically, you then need to find out which cable is the culprit.

    First ensure that the passthrough aerial lead from box to TV has its signal and earth connections properly made at both ends, that these are not shorting across somewhere, and that the cable has sustained no physical damage along its length.

    The HDMI cable is harder to check, as you would need specialist equipment to see if it is spraying RF about, but replacing it with a quality High Speed cable and seeing if the problem stops is a good check here.

    What you describe is in all ways consistent with an HDMI cable leaking RF onto the aerial cable, something that will be much worse if the aerial cable isn’t properly made; the tests above should eliminate both possible causes here.
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • ukstevesuksteves Posts: 9Member
    I tried rerouting (and in fact, swapping) the HDMI cable - but still no joy.  It worked on 720p, but not 1080p (presumably because 1080p generates more "data" and therefore interference?).

    Ghetto solution - which seems to be working so far :smile: - was to wrap the HDMI cable in kitchen foil.  With that "fix" in place, I can now watch COM7 and COM8 channels with the box set to output @ 1080p.  Now ready for the new series of Fifth Gear on Quest HD next week.
  • RoyRoy Posts: 14,212Member ✭✭✭
    uksteves said:
    I tried rerouting (and in fact, swapping) the HDMI cable - but still no joy.  It worked on 720p, but not 1080p (presumably because 1080p generates more "data" and therefore interference?).

    Ghetto solution - which seems to be working so far :smile: - was to wrap the HDMI cable in kitchen foil.  With that "fix" in place, I can now watch COM7 and COM8 channels with the box set to output @ 1080p.  Now ready for the new series of Fifth Gear on Quest HD next week.
    1080p versus 720p is probably a frequency thing. Your ‘ghetto solution’ has created a Faraday cage around the HDMI cable, which stops the interference leaking out.

    Did you try checking or replacing the aerial cable from the YouView box to the TV? It very much sounds like that has bad or non-existent shielding, shielding that would do what your foil is doing now.
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
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