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Discussion in 'Hobby Electronics' started by T.T., May 29, 2006.

  1. T.T.

    T.T. Guest

    Before I buy my next whizz-bang T.V. there are some very basic questions I
    would like to ask, and believe me, the local HiFi place or the local
    Retravision places are not where I will find the answers.

    I'll list some of these questions, and I hope the resident experts can point
    me to a publication that can answer them for me. (Silicon Chip isn't it.)

    1. Are the terms HDTV and digital TV pretty much synonymous? In other words,
    are all HDTVs digital, and are all digital TVs high definition?

    2. What is the pixel definition of a HDTV? For comparison, if our current
    analogue standard has 625 lines, how many vertical pixels has a HDTV set? Is
    there more than one standard? I have seen the figures 720 and 1080
    mentioned.

    3. Is broadcast digital TV, through a settop box, displayed on an analogue
    TV screen, much of an improvement on the same content broadcast as an
    analogue signal displayed on the same screen? If so, why? Does it have more
    than 625 horizontal lines? I believed that this was impossible because of
    the way a CRT screen is made.

    4. Will HDTV sets receive analogue signals without any kind of set-top box?

    5. Today's paper said that HDTV sets WILL need a set-top box to receive
    digital signals. Surely this can't be true. Is it?

    6. Will a HDTV set accept input from a current DVD read by a standard $300
    DVD player. If so, will it look any better than the same DVD played on the
    same DVD player displayed on an analogue TV set?

    7. Will a HDTV set accept input from one or both of the new DVD formats?
    Will my existing, big, expensive, CRT set do so?

    Are these questions simple enough to have simple answers?

    Am I in the wrong newsgroup?
     
  2. **Nope.

    In other words,
    **Yes. No.

    **See here:

    http://www.dba.org.au/

    For answers to all your questions.
    **It depends. At my last home, I had superb (analogue) reception. Adding a
    STB was virtually no improvment, except for those times when reception was
    marred by interference. At my present home, reception (despite the use of a
    high quality, prefessionally installed antenna) is crap (with analogue).
    Ghosting is (depending on material being watched) appalling. Using a STB (SD
    type) provides virtually perfect reception.

    If so, why? Does it have more
    **Not necessarily. Reception is better, due to the inherent rejection of
    interference by the digital system.

    I believed that this was impossible because of
    **Not necessarily. SD (Standard Definition) STBs will improve an analogue TV
    in most circumstances.
    **I have yet to see one which can, but they probably exist. Somewhere.
    **No. SOME HD (the minority) sets incorporate a digital tuner. Most do not.
    I susepct that the number of sets incorporating HD tuners will increase of
    the next few years.
    **Sure.

    If so, will it look any better than the same DVD played on the
    **Maybe. Maybe not. I rather like my old Sony Kirrarabasso (analogue, CRT
    set) as it provides a superb picture (whilst watching a DVD), compared to
    many of the LCD and plasma sets I've seen. Or course, my Sony cannot do HD
    though.
    **Possibly. Probably.
    **Possibly. Probably.
    **Some are. Some aren't.
    **Maybe.


    --
    Trevor Wilson
    www.rageaudio.com.au



    *** ***
     
  3. Poxy

    Poxy Guest

    Mate 'o mine has been steadily filling his house with plasmas - about 6
    months ago he bought a couple of LG screens that came with both an analogue
    and digital tuner inbuilt - at the time he said LG were the only ones that
    were doing the built-in tuner.
    I have yet to see a plasma that does as nice a picture as a half-decent
    CRT - by nice I mean devoid of posterisation/banding in subtle colour
    gradients and nasty sharpness. The only genuinely good picture I've seen on
    an LCD is on the Sony professional units.
     
  4. Phil Allison

    Phil Allison Guest

    "T.T."

    ** Yes - the improvement is very noticeable.

    But the TV set must have AV inputs with either S-video or 3 component.

    Digital stereo sound from a STB is far better than the wacky 2 frequency FM
    system used for TV in Australia too.


    ** No, but the colour resolution within each line is greatly improved.

    Plus no noise, ghosting, colour bleeding etc.

    Plus the choice of "letterbox" semi-wide screen format .




    ....... Phil
     
  5. T.T.

    T.T. Guest

    Thank you for your responses. I am a little better informed, but still have
    a question or two.
    Phil, you mention "semi widescreen format". Is that not a true 16:9
    widescreen?

    When I look at offerings in the local shop, there are LCD screens that seem
    to be standard analogue receivers, standard analogue aspect ratio.
    There are LCD screens that are much wider but still seem to be analogue
    receivers.
    There are LCD screens similar to these but with "an inbuilt set-top box".
    Is that what a digital TV set is? A wide, standard definition, 625-line
    screen with an inbuilt digital tuner?
     
  6. Phil Allison

    Phil Allison Guest

    "T.T."

    ** There is no such animal as a "digital TV ".

    Digital TV is a term that refers to the *broadcast signal format*.

    There are STBs in two varieties, SD and HD.

    There are TVs screens in two varieties, 4:3 and 16:9.

    Only a tiny few programs are broadcast in GENUINE HD quality at present.

    TV is currently in a state of transmogrification that will go on for the
    next 10 years.

    Hang on - it's gonna be a bumpy ride .....





    ......... Phil
     
  7. T.T.

    T.T. Guest

    That one statement alone answers a lot of my questions.
    Thank you.
     
  8. Mike

    Mike Guest

    Lots of snotty nosed kids with chips on their shoulders...
    Lot of stuff on the net that people are likely to post on this thread
    Lots of sales talk, some say a monitor with 1280x768 is hdtv - no it aint
    though it will show a 1920x1080 image it loses a bit.

    So 'HDTV ready' is a sales psuedonym for "it aint HDTV but will show it
    at lower res'

    Digital TV is only really a digital signal, your choice if you display
    it on an analog TV or a digital (DVI type) monitor for best display.
    True HDTV is 1920 x 1080 pixels, so a 240T samsung 24" LCD monitor will
    be more than capable of showing a true HDTV signal as its native resolution
    is 1920 x 1200. I have one and although it is reported as slow (20mS response)
    I havent noticed any issues at all with fast acting graphics etc And these
    days you might find one for less than $1000, though if I now had the cash
    I'd wait for the Dell 1920x1200 LCD monitors to drop a bit first...

    One particular TV station has an 'HDTV channel' such as 70 but its only
    720 x 576 but is at 50 frames per second, there normal stuff appears to
    be 720 x 576 but 25 frames per second interlaced.

    Only channel 9 (90) and as far as I know ABC (20) have true 1920x1080
    images but they are also interlaced, so 25 frames per second but not at
    all a problem on most LCD/Plasma monitors which have deinterlacing, and
    interestingly, having seen an LCD with 8mS vs one with 20mS response
    trying to show a 25 frame/sec interlaced transmission - I prefer the
    slower one, it seems to have a little less flicker. So all the hype
    about faster response is likely not all its cracked up to be...
    The Analog signal into a bog standard old analog TV is roughly equivalent
    to a 640 x 480 image but you lose some lines, so 400 lines is proba the
    best you'd expect from older analog sets. Given the SDTV transmission is
    720x576 25 frames per sec interlaced then you lose a heap by going from
    set top box to some analog output for an analog TV.
    You mean an HDTV monitor with 1920 x 1080 minimum native resolution (?) then
    yes most up to date monitors have analog inputs but its pointless feeding
    these with composite or S-video as these wont do much more tha 640 x 480
    with any sort of crispness. Best to have VGA or better DVI into a digital
    monitor. ie Although VGA is analog its far better resolution than S-video
    or composite (guh!), Component is between S-video and VGA and although
    (afaik) will do 1920 x 1080 is not as good as DVI or HDMI.
    Nope they can show a low res signal but why do it. a true HDTV set is
    1920 x 1080 and any analog signal from composite or S-video will be bad
    and nowhere as good as the component output from a SDTV or HDTV set top box.
    Might be a bit better as less analog stages and less losses but it depends
    on how good the sales people say the HDTV set is and how much you convince
    yourself (after you have paid heaps) that the HDTV is really really good
    when you find out its native resolution is only 1280x768 etc...
    More than likely the HDTV set will easily accept component or DVI,
    dont know anything about your CRT - did you tell us what it was ?
    Depends on your assumptions,
    Probably, go to aus.audio-visual.home-cinema or aus.dvd aus.tv.digital



    --
    Regards
    Mike
    * GMC/VL Commodore, Calais VL Turbo FuseRail that wont warp or melt !
    * High grade milspec ignition driver electronics now in development
    * Twin Tyres to suit most sedans, trikes and motorcycle sidecars
    http://niche.iinet.net.au
     
  9. T.T.

    T.T. Guest



    Are you saying that a computer monitor can be attached to a set-top box and
    receive broadcast digital TV?
     
  10. Mr.T

    Mr.T Guest

    Depends on the STB and monitor obviously. But it's possible.

    MrT.
     
  11. Mike

    Mike Guest

    Definitely, as long as the interface is compatible, ie Same type.
    I have seen a set top box put out VGA which of course is usable,
    also you can get convertors which go from Component, which seems the
    most common Set top box output, to VGA - or rather SVGA etc. Some
    SDTV only set top boxes have DVI out.

    Also the newer hdtv set op boxes have dvi, all the new large format
    LCD's I've seen for PC's have VGA and DVI input and some component :)

    Been using my Samsung 240T to watch HDTV for a couple of years now, only
    minor issue is that for hdtv you really need a fast processor, my lowly
    athlon 2800+ and 9250 radeon card can just keep up, though I cant do much
    else at the same time, like burn dvd's or do large backups without the
    hdtv skipping a frame now and then. But for SDTV, I can watch, record,
    play divx's all at the same time quite comfortably. Though I wouldnt
    recommend it you can record dvd's and do some dvd authoring transcoding
    in the background whilst watching sdtv full screen. A 720 x 576 sdtv image
    does look better on a 1920 x 1200 monitor than on a 1280 x 768 one, but only
    just and depends on how well the video card and player software can upconvert,
    the type of colour settings, how close you are to the screen etc etc


    --
    Regards
    Mike
    * GMC/VL Commodore, Calais VL Turbo FuseRail that wont warp or melt !
    * High grade milspec ignition driver electronics now in development
    * Twin Tyres to suit most sedans, trikes and motorcycle sidecars
    http://niche.iinet.net.au
     
  12. T.T.

    T.T. Guest

    Didn't make myself clear, did I. Once again.
    What I should have said, is this:
    Can a STB connect directly to a computer monitor, no computer anywhere, and
    display broadcast digital TV?
     
  13. Phil Allison

    Phil Allison Guest

    "T.T."

    ** Two posters have answered that in the ( conditional) affirmative already.

    So you dunno what VGA or SVGA is ??





    ...... Phil
     
  14. T.T.

    T.T. Guest

    I do.
    I don't know anything about STBs. I don't know what comes out of them. I
    don't know how a broadcast digital signal is dealt with in order to satisfy
    various LCD TV layouts. I don't know what is the resolution of a
    "widescreen" LCD computer monitor, or what use it is other than to play
    movies. I live in the bush. My only contact with such matters is with
    semi-literate counterjumpers in a Retravision, or in Silicon Chip with its
    battery zappers, computer-controlled burglar alarms and doorbells that sound
    like a V8.
    I would like to know, and this is why I come to this newsgroup.
     
  15. Phil Allison

    Phil Allison Guest

    "T.T."

    ** Then act like you do.

    Some ( a few ) STBs have SVGA outputs on them.

    So you can use up that spare monitor.





    ........ Phil
     
  16. Mike

    Mike Guest

    Sorry, thought I answered that,

    Yes you can if the interfaces are compatible.

    Most computer monitors have VGA, some STB have VGA *therefore* you can show
    the signal on the monitor and I might add at a much higher resolution than
    any most ordinary analog TV crts can display.

    --
    Regards
    Mike
    * GMC/VL Commodore, Calais VL Turbo FuseRail that wont warp or melt !
    * High grade milspec ignition driver electronics now in development
    * Twin Tyres to suit most sedans, trikes and motorcycle sidecars
    http://niche.iinet.net.au
     
  17. Mr.T

    Mr.T Guest

     
  18. jfc

    jfc Guest

    Ostia Technologies 6' (3) RCA Component Video to HD15 VGA Cable.

    High quality cable that allows connection of 3 RCA Component Video outputs
    to a VGA Component input on a Plasma, LCD, or Video projector display.

    Buy now price $4.99



     
  19. Mr.T

    Mr.T Guest

    OK, the number of cheap STB's with component out is still limited. But I
    certainly agree there are often more ways than one to connect many devices.
    Scart adapters being a common requirement with many STB's for example.

    MrT.
     
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