Dropouts in sound and video on live or recorded TV

Forum Forums Freeview HD Aura UHD Dropouts in sound and video on live or recorded TV

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  • #22052
    Anonymous
    Inactive

    I’ve tried looking this up but nothing seems to fit with what I’m seeing…

    While watching either live or recorded material there are pretty regular sound and video dropouts varying from an instant to a second or two. Occasionally a freeze or blank screen requiring a restart to continue.

    I don’t think this is a signal probelm as by replaying the recorded material the dropout doesn’t occur in the same place.

    The connection to the TV is via top-spec HDMI, and both ends of the cable are firmly in place.

    My question is ‘is this frequently seen or should I contact Humax to have it resolved’?

    Thanks in advance for any help

    #106820
    grahamlthompson
    Participant

    What software version and update date do you have ?

    FVP-button – Settings – Freeview-Play Info- system information.

    #106821
    Martin Liddle
    Participant

    Gizmologist – 5 hours ago  » 

    I don’t think this is a signal probelm as by replaying the recorded material the dropout doesn’t occur in the same place.

    The connection to the TV is via top-spec HDMI, and both ends of the cable are firmly in place.

    It might be helpful to say what make and model of TV you have? In the past their with other Humax models there have been issues with sound dropouts on certain models of TV.

    #106822
    Anonymous
    Inactive

    System infi is firmware 00.09.21, update date Jun 17,2021 05.28.57pm

    TV is LG OLED48C14LB, a recent purchase.

    I’m pretty sure the problem has only been in the last week or so, not in the first week or two of ownership of the TV. We’ve had the aura a couple of months. I’ve owned several older humaxes the foxt2 being the best. Other family members have had others and I’ve kept them going for years.

    I’m tempted to think it’s an HDMI issue. I’ve removed a right-angled adapter from the TV end and it has improved the issue but not solved it.

    #106823
    grahamlthompson
    Participant

    Guessing it’s down to the current high pressure conditions. This makes UHF travel further so transmitters you normally can’t see become receivable. If one of these uses the same UHF carrier as your local transmitter uses they interfere with each other. Tune to a channel with issues. Check the signal info. FVP button – settings (the cog icon) – channel and Broadcast Signal test. If the quality is varying then you have the likely reason.

    Seperate your HDMI cable as possible from the aerial connections. Do not run them in parallel.

    Make up aerial connections using double screened WF100 sat grade cable. Terminate with screw on F connectors using F to Belling Lee adaptors where needed.

    #106824
    Martin Liddle
    Participant

    grahamlthompson – 1 hour ago  » 

    Guessing it’s down to the current high pressure conditions. This makes UHF travel further so transmitters you normally can’t see become receivable. If one of these uses the same UHF carrier as your local transmitter uses they interfere with each other. Tune to a channel with issues. Check the signal info. FVP button – settings (the cog icon) – channel and Broadcast Signal test. If the quality is varying then you have the likely reason.

    But the OP said in his original post that rewinding and replaying didn’t show blips in the same place?

    Seperate your HDMI cable as possible from the aerial connections. Do not run them in parallel.

    Make up aerial connections using double screened WF100 sat grade cable. Terminate with screw on F connectors using F to Belling Lee adaptors where needed.

    Good advice particularly about keeping HDMI and aerial cabling well separted.

    #106825
    Anonymous
    Inactive

    This is the first time I’ve visited the forum for many years but I immediately noticed these posts as I only looked to see if anyone is having the same problem which I’m getting on my FVP-5000T. I record a lot, mainly in HD, sometimes three programmes simultaneously. This situation occurred last Saturday and all the recordings exhibited video and sound drop-outs. Of course as all the stuff was in HD it was from my local HD Mux and I can’t help but wonder if this might be the problem. Is my recorder capable of recording three separate programmes simultaneously? As an experiment I’ve changed my recording habits. Initially only recording one HD broadcast at a time when other recordings are made in SD. All was OK. Tonight I’ll be recording two HD broadcasts at 9.00pm and another in SD. I’ve run a disk check (NOT FORMAT) and this went through OK. Not sure what a disk check does, I’m guessing at a read only test looking for checksum and address errors as I used to run when having to work for a living. Things have probably changed, it was a long time ago. BTW signal test shows 100%.

    #106826
    Martin Liddle
    Participant

    jacklx – 19 hours ago <a href=”https://myhumax.org/forum/topic/dropouts-in-sound-and-video-on-live-or-This situation occurred last Saturday and all the recordings exhibited video and sound drop-outs. Of course as all the stuff was in HD it was from my local HD Mux and I can’t help but wonder if this might be the problem. Is my recorder capable of recording three separate programmes simultaneously?

    Yes it should be capable of recording three HD programmes simultaneously but it will be causing the box to run hotter than normal and given the current ambient temperatures that could be an issue. Is your box in a well ventilated position (ie not in a cabinet or in the middle of a stack of other boxes)?

    Not sure what a disk check does, I’m guessing at a read only test looking for checksum and address errors as I used to run when having to work for a living. .

    At a guess it will run a short S.M.A.R.T. self test. One source on the web suggests this includes:

    “Electrical Properties: The controller tests its own electronics, and since this is specific to each manufacturer, it cannot be explained exactly what is being tested. It is conceivable, for example, to test the internal RAM, the read/write circuits or the head electronics.

    Mechanical Properties: The exact sequence of the servos and the positioning mechanism to be tested is also specific to each manufacturer.

    Read/Verify: It will read a certain area of ​​the disk and verify certain data, the size and position of the region that is read is also specific to each manufacturer.”

    BTW signal test shows 100%.

    Could you provide both the signal strength figure and the signal quality figure please?

    #106827
    Anonymous
    Inactive

    Replying to Martin,

    The recorder was situated beside a Foxsat recorder on top of both was a Bose Solo sound box. In view of your observations regarding temperature I have now rearranged things so the Bose box has both recorders on top of it, side by side. I have fabricated 4 spacers which do not impede the ventilation slots underneath the 5000-T, the gap is now 6 cm which I hope is adequate. All of this is situated on a glass shelved stand, NOT an enclosed cabinet.

    I have monitored the signal strength and quality while recording 3 HD programmes simultaneously, both show up as 100%, I've attached a photo.

    Now TV frequencies are being given to the mobile phone industry there is not much 'space' between muxes. My HD mux is 35, also used are 32,33,34,and 36. (all from the Mendip transmitter. I wonder if this could cause problems? I know everything should work OK but over the years when I see or hear the word 'should' I mentally replace it with 'might'.

    I'll carry on recording in HD, these glitches are a nuisance but if a recording becomes unwatchable there's always 'Catchup'.

    As for the inbuilt disk test I guess we will just have to hope it's adequate.

    [attachment=92087,2091]

    #106828
    Anonymous
    Inactive

    Replying to several posts…

    Martin – I replied with my TV make and model – does this one ring a bell with you, or is there a specific make that has problems please?

    Also, your observation to Graham that I had originally posted that when replaying a recording, after a dropout a quick rewind proved that the dropout did not occur in the same place, or even at all. I have done several tests over the last 2 nights and I honestly don’t believe the dropouts are on reception.

    Graham’s points about reception are totally valid, and all make sense, even though I don’t think that my problem is a reception one. As there is at least one other following this thread I feel I should add one thing Graham didn’t mention, prompted by one of Jack’s observations. In the summer after all of the ‘freeing up’ of bandwidth from the TV frequency allocation for use by the 5G phone network we suffered from high pressure causing reception problems here – I’m in West Sussex on the fringe of the Midhurst transmitter. It was only then I realised our new mux frequencies were well down in the range, and that the C/D aerials still on most of our neighbour’s rooves were not helping. The advice then from the broadcasting authorities was to replace any C/D aerials with a broadband aerial. They also advised removing any old aerial amplifiers, particularly from the head end (near the aerial). Although we already had a broadband aerial we still had an old amp in there and removing it transformed our reception in times of high pressure. We rarely see problems nowadays, although every retune seems to result in a change of frequency of at least one mux so I’m touching wood. I’ve looked to see if the Mendip transmitter was also C/D back in the analogue days but can’t find anything – sorry. By the way I’m a licenced radio amateur so I understand a bit about propagation, reception and aerials.

    Removal of the right-angled HDMI adapter has virtually resolved the original dropout problem – hence the delay in posting this as the problem has become much less frequent so getting examples has been difficult. HDMI has gone through several generations from its initial incarnation, and has become considerably more echnically demanding. I know from another incompatibility a while back that when HDMI is attached/first used it negotiates to establish whether the spec of each end, and all interconnects, are up to scratch. What I haven’t been able to find is a clear description of whether the negotiation is only carried out on first connection or initiated on every use. Does anyone have a link to a good technical description? It may be that when changing around the HDMI cables on my new TV I need to force both ends to ‘forget’ and renegotiate.

    Sorry for the long post, but I wanted to try to ensure that what had been one issue is clear to people trying to solve what may be a different issue.

    All thoughts gratefully received!

    #106829
    Anonymous
    Inactive

    Back in the days of analogue here in the Mendip area the transmission frequencies were in the upper range, I don’t recall which bands but I know that the aerials on people’s chimneys had small dipoles, directors etc. Now we are at the other end of the spectrum. There are still a lot of these ‘old’ aerials in use but I’m only aware of one person who needed to upgrade. She used a relay station (Hutton) which only transmitted two muxes plus an HD mux but after the last retune the frequencies changed to the ‘bottom’ of the spectrum so she could no longer receive BBC and ITV West from the relay station. Despite her aerial being vertically polarised she was able to pick up all SD stuff from Wenvoe, but this isn’t much use unless you’re happy to watch Welsh news. I had to use manual tuning for both the relay station and Wenvoe for the muxes which are the same throughout England. During the last retuning I noticed one of her neighbours had a new broadband aerial on the chimney pointing towards Mendip, despite Bleadon Hill being in the way. I called on the people who assured me that they were able to watch everything from Mendip so now the old aerial pointing at Hutton has been replaced. Sorry this is such a long story but it leads me up to a little ‘muddying of the waters’. Might the adjacent transmissions from Wenvoe, nothing in the way apart from the Bristol Channel, be interfering with the transmissions from Mendip and causing the glitches???

    #106830
    Anonymous
    Inactive

    An addition; reading all the previous posts I’m assuming, perhaps wrongly, that the glitches are only occurring with HD broadcasts. Has anyone seen glitches on SD recordings?

    #106831
    Anonymous
    Inactive

    Not sure if this is related but I get frequent dropouts from certain channels after 15-30minutes of watching.

    Channels like Yesterday, 5Star, Pick, Blaze on signal channels 42, 44, 47. (Are these what you call muxes ?)

    On first start up they are signal 100% quality 100%…then after 15-30 min the quantity drops and fluctuates between 40 – 70% meaning watching is frustrating at best and un-watchable at worst.

    For example I was viewing Fifth Element tonight on 5Star, for the first 30 min fine…now it’s impossible to watch.

    Other channels, bbc, itv, c4, HD channels are all fine and remain fine.

    Not sure if it is a box issue or aerial issue. I have reported it to support and waiting to here back.

    #106832
    Anonymous
    Inactive

    Dan_in_stoke – 39 mins ago  » 

    the quantity drops and fluctuates between 40 – 70% meaning watching is frustrating at best and un-watchable at worst.

    That can be a symptom of over loading the signal strength.

    Dan_in_stoke – 39 mins ago  » 

    signal 100%

    Different models and even different units can vary by what they mean by 100% but that is at the top end of what you would hope that the recorder can cope with. It probably only displays up to 100% and so if its stronger will still show 100%.

    If you are using a signal amplifier then try and remove it. Otherwise try a cheap variable attenuator.

    #106833
    Anonymous
    Inactive

    First I’ll answer a question I came up with earlier. Yes I have seen a glitch on a SD recording. Not as obtrusive as the ones seen on HD, a dark horizontal line from side to side. It IS recorded and replayable as are the HD glitches. Perhaps I should give up on HD, but not until I can see if the repositionong of my recorder has improved matters.

    But now in answer to Dan_in_stoke. It looks as if the numbers, 42,44 and 47 do refer to the muxes.

    https://www.freeview.co.uk/corporate/platform-management/channel-listings-industry-professionals

    This page from the Freeview website lists all programmes and indicates which mux is associated with each programme, e.g Yesterday (programme 26) is broadcast on ARQB mux in UK except the Channel Islands.

    https://www.freeview.co.uk/help/manual-retune

    This is also from the Freeview website and if you scroll to where it says

    ‘Detailed transmitter information’ and click it. Enter your postcode and house number which then reveals another page which gives loads of useful information such as your local transmitters and lower down the page details of which muxes are used. I’ve tried a screenshot which doesn’t work. This might

    https://www.dropbox.com/s/0fz0yoxdjlly2p8/Untitled%202.odt?dl=0

    it shows what I pick up from the Mendip transmitter. The mux numbers, 32,33,34,35 etc. are the numbers one needs to use if manual tuning is necessary.

    But this doesn’t address your problems with programmes such as Yesterday on ARQB. 5Star is broadcast on the SDN mux. The problem may be aerial related but the information contained on the page showing which muxes are used in your area also tells you what power levels sre anticipated, another ‘traffic light’ system, green for good, red for bad reeption.

    I’ll now post this to see if the links work.

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