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FREEVIEW F.A.Q.s

Discussion in 'Freeview Forum' started by scribbler101, Sep 14, 2008.

  1. scribbler101

    scribbler101 Member

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    There are a few topics that keep coming up, and getting the same initial responses. So to save time:

    ALMOST ALL QUERIES CAN BEST BE DEALT WITH FROM KNOWLEDGE OF YOUR LOCAL FREEVIEW TRANSMITTER AND SIGNAL STRENGTH. This can be got from WOLFBANE - see below http://www.avforums.com/forums/freeview/826100-freeview-f-q-s.html#post7958794 - or if you are confused, post your postcode. And for details of your local transmitter, go here http://www.ukfree.tv/txlist.php and select by name or postcode. Once you get to the page that looks like this http://www.ukfree.tv/txdetail.php?a=SK113003 you can see what TV channels are on the same frequency (Multiplex/Mux) and whether the frequencies now in use (middle line) are same or different to analogue, so if existing aerial likely to work well.

    RECEPTION/AERIALS - Plug your postcode into this link and post the results. It will let people respond knowing where you are starting from! Your location is useful. Up to you if you wish to disclose your postcode or not. *** WOLFBANE *** See below for explanation.
    http://www.wolfbane.com/cgi-bin/tvd.exe?

    "DIGITAL" AERIALS - do not exist! For the same frequencies analogue and digital need same aerials. If you have an existing aerial try it first - as directly into the TV/box as possible, not split or chained for preference.

    PORTABLE AERIALS - rarely work with digital TV - though they may do after switchover. Please do the Wolfbane check, and if possible try your set with a proper aerial if you have one in the house.

    WHICH TRANSMITTERS NOW AND AFTER CHANGEOVER? One thing not on Wolfbane is the post-switchover transmiter details. Clear postcode below and re-enter yours to see which channels are/will be in use
    http://www.ukfree.tv/txdetail.php?a=SD660144

    DIGITAL SIGNAL STRENGTH - WEAK UNTIL SWITCHOVER - Until the analogue signal goes off the digital signals are weak to avoid interference. At analogue swith-off the digital strength will increase - typically 5 or 10 TIMES (500-1000%). This means that mostly after switchover you will be able to get digital with whatever aerial you have now for analogue. But if you can't wait you may have to pay for better aerials that eventually you would not have needed. Here's a table of present and future transmission strengths - provided after a question from some annoying busybody who is pseudonymous here.
    http://www.ukfree.tv/fullstory.php?storyid=1107051475

    LOSS OF CHANNELS - There has been a change in the DVB-T transmission standard (The Network Identification Table NIT) which is confusing many receivers/boxes. Typically BBC1/2 etc are lost or appear as 800 numbers. Some sets can be cured by a programme upgrade. A few are useless. This problem only appears when you retune. I will add a link when I find it!
    NIT - Network Information Table. A part of the data broadcast that tells digital TV receivers about the channels available, the numbers that they should be allocated to, and the frequencies used by transmitters. In some parts of the UK, the NIT is now split into several parts, which causes problems scanning channels on boxes that do not correctly interpret the information.
    http://www.frequencycast.co.uk/freeviewlandfill.html
    EDIT: See link for a fine explanation of the problem
    http://www.avforums.com/forums/freeview/856179-watchdog-2.html#post8180512
    ...and more facts here
    http://www.avforums.com/forums/free...coldfield-setpal-digiboxes-2.html#post7399313
    ... and a list of dodgy boxes
    http://www.ukfree.tv/fullstory.php?storyid=1107051492
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    Last edited: Mar 8, 2009
  2. scribbler101

    scribbler101 Member

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    The Official switchover site - dates and info
    http://www.digitaluk.co.uk/home2

    BBC Digital Transmitter maintenance info
    http://www.bbc.co.uk/reception/transmitters/index.shtml
    http://www.bbc.co.uk/reception/news/index.shtml#redbutton

    List of channels (programmes) on each channel (broadcast) aka MUX (Multiplex) - see post 7 on linked thread
    http://www.avforums.com/forums/showthread.php?t=826462
    and here's the official version
    http://www.dtg.org.uk/retailer/dtt_channels.html
    LCN - Logical Channel Number. The LCN is the digital channel number that is used to select a channel on your box, for example 1 for BBC1 or 80 for BBC News 24. LCNs are constant, just as you might find almost every analogue TV has BBC1 on the first button, BBC on the second and so on. Don't confuse the LCN with the UHF channel; all the channels on a multiplex will have the same UHF channel, but individual LCNs.

    And the reciprocal version - identify the transmitter from the channels in use
    http://www.ukfree.tv/findbychannel.php?C=21
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    Last edited: Nov 4, 2008
  3. fernandez

    fernandez Active Member

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  4. Fred the Oyster

    Fred the Oyster Member

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    Last edited: Sep 16, 2008
  5. fernandez

    fernandez Active Member

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    Last edited: Sep 17, 2008
  6. scribbler101

    scribbler101 Member

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    Last edited: Feb 6, 2009
  7. ROYOLD

    ROYOLD Active Member

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  8. scribbler101

    scribbler101 Member

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    Re: Aerial cables - Is there a difference?
    This is the definitive review on aerial cable.

    http://www.wrightsaerials.tv/article...ty-hmdi-m.html

    The bottom line is that yes there is an enormous difference between the best and the worst.

    I took the liberty of copying smjx09's excellent post.

    All I would add is that in many cases the cheap old cable may be just fine - so don't replace it if you don't have a problem.
    Last edited: Feb 6, 2009
  9. ROYOLD

    ROYOLD Active Member

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    If you need help connecting your freeview STB or (IDTV) Integrated Digital TV set with other AV equipment then the SONY Europe Connectivity Website in Belgium gives illustrated diagrams for many different combinations.

    Sony Europe Customer Support Portal
  10. scribbler101

    scribbler101 Member

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    I have had confirmed by wolfbane that they do not have an explanation but will do one. EDIT: http://sam-radford.me.uk/wolfbane.htm has a good guide here.

    So here's a brief one to start with. Open

    UK digital TV reception predictor

    12ABCD Are the 6 Multiplexes - frequencies each carrying several Logical Channels (programmes). For each
    UHF - the transmission frequency channel (not same as a logical channel!)
    ERP - Effective Radiated Power - strength. NB Pontop Pike is 10,000 watts. Fenham only 40 watts - local repeater to get round a hill or similar. NB Pol H/V later
    AOD - How high transmitting aerial is. Sometimes aerials at different heights up the mast - eg Fenham D - 7m below the rest.


    Gp - The aerial group appropriate for the range of frequencies in use
    Pol - Horizontal or Vertical polarised signal. Main tx H; repeaters V to avoid mutual interference. Look at local roofs and see if little rods vertical or horizontal.
    OS Grid/Ground Height of transmitter
    Field - Signal strength predicted at your location and aerial height input. above/below 30 seems to be the yes/no level.
    Distance/(compass) Bearing from you to tx. Do local rooftop aes point that way?
    Antenna suggestion - tends to the conservative.


    If it says you have nothing try lying that you have a 200m high aerial.
    Last edited: Dec 25, 2008
  11. scribbler101

    scribbler101 Member

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  12. scribbler101

    scribbler101 Member

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  13. scribbler101

    scribbler101 Member

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  14. radioredcat

    radioredcat Member

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    A lot of the time people ask are bigger aerials,more elements,adding amplifiers,Well i have done some tests with no speacial equipment just a couple of aerials and a freeview box and the signal from the wrekin at 58 miles and also sutton coldfield at 71 miles.

    Image10.jpg
    These are my aerials at the top an old (wolsey colour king) grid aerial with no amplifier and underneath a triax 92 element with a masthead amplifier this goes into a 4 way inside.
    So first iv'e used the triax and the pics are from using the triax aerial and amplifier.

    1-MUX 1 TRIAX.jpg 2-MUX 2 TRIAX.jpg 3-MUX A TRIAX.jpg 4-MUX B TRIAX.jpg 5-MUX C TRIAX.jpg 6-MUX D TRIAX.jpg
    From the pics above you will notice the signal strength in % and the signal quality and on a good signal it reads 4.0 10.7 when the quality is bad the numbers start altering.

    1-MUX 1 CK.jpg 2-MUX 2 CK.jpg 3-MUX A CK.jpg 4-MUX B CK.jpg 5-MUX C CK.jpg 6-MUX D CK.jpg
    From the pics above iv'e used the colour king with no amplification just plugged straight into the box.
    As you can see the difference the signal quality is varying on mux c-d and the signal strength is lower but it still works ok but there's no margin for error.
    So you will think well you would have thought there would be a massive difference between the two aerials well there isnt.
    What is different though is the directivity,or foward gain which means the colour king will receive signals well off beam where as the triax will reject better a signal coming from the same direction and a log periodic will be better still thats why the broadcasters use them.
    Both aerials are pointing south but they still receive winterm hill as well so i have to manually tune the receiver if i don't i end with some muxes from the wrekin and some from winter hill.

    Just out of interest i did some tests from sutton coldfield.

    1-MUX 1 TRIAX SC .jpg 2-MUX 2 TRIAX SC.jpg 3-MUX A TRIAX SC.jpg 4-MUX B TRIAX SC.jpg 5-MUX C TRIAX SC.jpg
    As you can see only five muxes i usually only receive mux 1-2 but today there is a slight lift,Mux D is on CH 55 which is BBC1 winter hill and is not receivable.
    Now if you look at mux c it did tune in but the quality is bad because there is a weak BBC 1 WALES on CH 52.
    Needless to say i plugged in the colour king and the signals were rubbish

    SUTTON COLDFIELD CH 50 TRIAX.jpg SUTTON COLDFIELD CH 50 COLOUR KING.jpg
    The pics above is sutton coldfield CH 4 on CH 50 analogue.

    CH 51.jpg CH 52.jpg
    The pics above is CH 51 which is mux B sutton coldfield and CH 52 mux C if you compare the two pics you notice a difference in the looks of the noise CH 51 is clean digital noise where as CH 52 has a lining effect and that is BBC 1 WALES which is very weak reflected signal but enough to stop the mux working.
    So if you are having mux problems have look with the analogue tuner at the digital channels and see if it's clean.
    The aerials are on the east side of the house to reduce the welsh signals.
    I should also say that the colour king was where the triax is now and i put it there in 1980 till last year and took the opportunity to do some expereiments.
    hope this has been a help as i like tinkering.

    Here's an update on yesterday i tried an old amplifier on the colour king for the wrekin,Its a three stage amplifier with a quoted gain of 36db so when i connected it up and tried i could not receive mux C-D because the amplifier is too noisy which the most important factor when choosing an amplifier.
    There should be these days no excuse for amps whith a high noise figure 2-3 db is the norm but the lower the better.



    andy

    Attached Files:

    Last edited: Mar 7, 2009
  15. scribbler101

    scribbler101 Member

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  16. mrbenn

    mrbenn Member

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  17. mike7

    mike7 Active Member

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    A very common problem for people moving into new premises is to find they cannot get Freeview because the previous occupant has walked off with the power supply box for the aerial amplifier. Some tvs, pvrs or set top boxes also supply the 12v needed to be sent up the cable to the amp. Check to see if there is an amplifier at the aerial end. Simple fix is to buy a suitable power supply from Maplin. They are about £20,

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