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Picture glitches on freeview

Discussion in 'Freeview & YouView' started by ted26, Sep 7, 2003.

  1. ted26

    ted26
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    I recently installed a netgem freeview box which after a few days seems very good :)

    I just have one small problem of slight glitches appearing on the picture every time another appliance in my home pulls power from my plug ring main!( eg central heating )

    Is there any way i can stop this?
     
  2. MarkE19

    MarkE19
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    If the noise is coming from the ring main then a surge protector from Belkin etc would help to remove the glitches. These are available from Dixons, Argos etc for around £20. I have them on all my sockets used for AV gear & PC equipment.

    Mark.
     
  3. cybersoga

    cybersoga
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    It's more likely to be radio frequency interferrence being picked up by the aerial or cable. If you havn't had your aerial or cable upgraded, you might want to think about that. If it happens every time the heating kicks in then this is probably due to a faulty thermostat.

    Some set top boxes are more sensitive to interferrence than others.
     
  4. ted26

    ted26
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    After switching several apliances on and off round the house i can confirm its coming from the sockets ! even washer causes same glitch.

    Went and purchased a 4 way cheap surge protected socket from B&Q which does not stop the glitches.

    would that surgre protector from belkin be any better markE19? Did i get what i paid for :thumbsdow
     
  5. MarkE19

    MarkE19
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    To be honest, if the surge protector made no difference then a more expensive unit is not likely to cure it either.
    As cybersoga said radio frequency interferrence is the most likely cause. Your best bet would be to get a continuous coax lead from ariel to DTT box ie no wall mounted socket with a fly lead plugged into it. Replace the coax with double shielded sattalite coax.
    A faulty thermostat is also a common cause. I have heard of PC's crashing everytime the heating switches on. Once they replaced the thermostat it stopped crashing the PC. As the thermostat is unlikely to be on the same ring main as your sockets I would be very surprised if it was due to power surges.

    Mark.
     
  6. ted26

    ted26
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    The heating takes its power from the ring via a switched fuse spur!

    If i switch a table light on and off it causes the glitch! where do radio frequencies come into that?

    My freeview box is already fed with brand new shielded coax and is on its own seperate ariel.

    any other ideas? :)
     
  7. kwangomango

    kwangomango
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    If you do use a wall plate, it could well be worth using a fully screened one. They are a couple of quid at my local Wilkinsons.
    Have a look over on the Digital Terrestrial forums at digitalspy. Thre may be some good advice there.
     
  8. Pod Person

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    Electrical impulse interference at work here I believe. I get break up from passing traffic. Don't you just love new technology.:suicide:
     
  9. LV426

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    Yep. Any electrical appliance, including switches, theromstats et al, can cause a momentary radio frequency transmission which can interfere with reception of radio signals.

    On a regular radio, it might be heard as a click; on an analog TV signal it might be seen as a tiny speckled flash on part of one (or more) of the scanlines in the image. On a digital TV signal it may manifest as a momentary break up (blocking) of part of the image perhaps coupled with a click in the audio.

    All these artefacts are made worse/more intrusive the weaker the radio signal being received is. The solution is to do any or all of these:

    > increase the strength of the signal by using a better aerial and/or masthead amplifier (note - it must be a masthead amp - a local amp will amplify the interference, too)

    > increase the signal strength and/or reduce the propensity for the interference to break into the signal, by replacing/upgrading the cable from the aerial to the equipment, at the same time removing as many plugs and sockets as possible on the way.

    > fit the errant appliances with interference suppressors.
     
  10. Mr.D

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    If you use the RF uplink from the box to the display then alos replace this with a decent coax cable. I found it made all the difference to this type of interference on my digiboxes. The crappy lead they come with seems to just act like an antenna and leakc interference which ironically interferes with reception.
     
  11. Arthur Dent

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    I've found the fully shielded Maxview with an F connector to do the business. Bit of a pain if you need to keep unplugging, but it makes a much better connection than the "rope in a well" co-ax plug and socket. B&Q's do 'em. ;)
     

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