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Breakup of Recent BBC 4 Recording

Discussion in 'HDR-FOX T2 Freeview Recorder' started by Nontech, Jan 1, 2017.

  1. Nontech

    Nontech Member

    Recently recorded from BBC4, on viewing there was a lot of picture breakup.
    Have now looked at the Signal strength from TV, it's showing BBC1 as 87% but BBC4 as 75%
    I'm on the Tacolneston transmitter.
    Is this a normal reduction from BBC1 to 4?
    Also where can I find the Multiplexer chart for stations?
    Thanks
     
  2. Black Hole

    Black Hole Felonius Gru

    75% is fine. What you really need to look at is the quality figure, and do so via Menu >> Settings >> System >> Signal Detection.

    If you want to know how your system is currently tuned, use WebIF >> Diagnostics >> Mux Info. If you want to know how it should be tuned, see Things Every... (click) section 2.
     
  3. grahamlthompson

    grahamlthompson Well-Known Member

  4. Trev

    Trev The Dumb One

    What's happening to Com 6&7 after 2019?
     
  5. grahamlthompson

    grahamlthompson Well-Known Member

    Suspect the OP does not have the custom firmware installed. He asked the same question on MyHumax.
    Spectrum will be used for other services.

    I imagine the channels will be absorbed into the other mux with the increase in capacity due to DVB-T2 modulation and probably H264/AVC encoding for all channels (HD and SD).

    Pretty confident from follow up post at MyHumax, OP's issue was weather related CCI (The channels he was recording was BBC1 HD and BBC 4-HD (Com 7).
     
  6. Ezra Pound

    Ezra Pound Well-Known Member

    Yes, the 6 main Muxs output 100,000Watts, Com7 (BBC4 HD) is only 27,400Watts
     
  7. Trev

    Trev The Dumb One

    Run out of 'k's Ezra?:)
     
  8. Adam Claridge

    Adam Claridge New Member

    We have even worse problems on our 'standard', ie non-customised device - it seems that all HD channels suffer from degradation and pixelation, whether recorded or watching live. We haven't introduced any additional devices for some time; I think this started on occasional viewings about 4 or 5 months ago, but is now almost continuous! As far as I can see the signal strength is fine and the quality is at 100%.

    Is the hard-drive on the way out or is this a software issue and can I do something about either or both of these?
     
  9. af123

    af123 Administrator Staff Member

    It's could well be a hard drive issue. The custom firmware might be able to fix it for you or will certainly give more insight into it.
     
  10. Trev

    Trev The Dumb One

    As an alternative to the box, could it be an aerial problem? What signal strength do you actually get on each Mux channel, especially on BBCB (the HD one with BBC1HD, ITV HD etc on it)?
    Would that give a problem on live TV af?
     
  11. af123

    af123 Administrator Staff Member

    It's less common but can if there are problems with the TSR area of the disk.
     
    Trev likes this.
  12. Adam Claridge

    Adam Claridge New Member

    I'm not sure how I check the signal strength of the aerial or each Mux - can I do this within Settings?

    Also, when NOT viewing via the Humax, ie just using the TV's own tuner, there is no picture degradation.

    On the Humax, as far as I can tell, the SD channels are unaffected!
     
  13. Trev

    Trev The Dumb One

    On the Hummy. Menu>Settings>System>Signal Detection. Read off Strength and Quality. FYI mine is at 70%/100% for my HD Mux on Ch 22.
    Then use the arrow keys to step through the Mux's. Check that the Mux channels are what you would be expecting from your 'local' transmitter while you are at it.
     
  14. Black Hole

    Black Hole Felonius Gru

    Check which broadcast channel number (not the service LCN) is affected by pressing OK within the live broadcast (to bring up the service list) then press the Info button "i". The Channel Information pop-up gives you the LCN, service identification, channel number, broadcast frequency, and channel bandwidth.

    To check the signal for that particular channel number: Menu >> Settings >> System >> Signal Detection, then select the channel number in question and monitor the strength and quality bars for a few seconds. This is the only way* to get a live view of reception conditions - the figures in WebIF >> Diagnostics >> Mux Info are static and recorded in the database at the time of a retune (and are only valid if it was an automatic retune rather than a manual one).

    Interference between the HDMI lead and the aerial lead can cause signal degradation and loss, depending on the amount of data being sent to the telly on the HDMI. Changing the resolution on the HDMI lead (V-FORMAT button) can reduce or eliminate this (at the cost of picture resolution). If it does, you need to look at the quality of the leads and whether you can move them apart.

    That this is happening specifically on HiDef services suggests that either the HD channels are at a lower power, or (as suggested above) the higher data rate is causing the HDD not to be able to keep up because of access retries slowing down the system (and therefore a suspect HDD). See Quick Guide to Disk Recovery (click).

    See also Poor Reception Problems (click).

    * There is an option in the hidden service menu which allows for the individual tuners to be tested separately.
     
  15. prpr

    prpr Well-Known Member

    That's not true. Figures from a manual tune are perfectly valid. It's just that it zeroes everything apart from the mux. you are tuning, which is rather useless (although this can be worked around in the customised firmware world).
     
  16. Black Hole

    Black Hole Felonius Gru

    So only one of the figures is valid then.
     
  17. Adam Claridge

    Adam Claridge New Member

    Thanks everyone, looks like a Saturday morning exercise! I'll let you know if I get things sorted.