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So what's the truth about lead-free solder ?

Discussion in 'Electronic Repair' started by Eeyore, Jul 24, 2007.

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  1. Arfa Daily

    Arfa Daily Guest

    You must have some rubbish kit over there then. A good PAL analogue TV set,
    with a decent signal going in, beats a crappy highly compressed digital
    signal, hands down, every time. If you want to talk about a picture
    decorated in artefacts however, then digital is the hands down winner every
    time in that category ...

    Anyways, although your analogue terrestrial *transmissions* may have ceased,
    I think it is unlikely that everyone in Holland has just thrown all of their
    analogue-input ( both RF and composite ) portable TV sets and such in the
    bin, and as long as that is the case, there will still be a need for
    analogue outputs on other equipment such as STBs. Bear in mind also that an
    analogue signal does not need to be UHF modulated, to be PAL encoded. One of
    the default modes of the SCART standard is good old PAL-encoded analogue
    composite video, both input and output.

    Arfa
     
  2. Well, maybe you do not have digital yet.
    And for sure you have not seen the HDTV tests on satellite like those from France.
    I am not denying mpeg2 compression has artefacts, but those very much depend on
    bandwidth (bitrate), and bitrate is a bit less then 4000 kbps on digital here.
    (non HD).
    Although that is less then DVD max, it is absolutely enough for a stunning
    _noise free_, _moire free_ (PAL & NTSC composite), _easy to record_ (as .ts),
    _no loss editing_ (digital), _space saving_ (both on disk and in the ether),
    allowing as many sub-channels as you like (more languages, more subtitles,
    teletext, other services, timecode, all in the same stream).

    It seems to me you do not _HAVE_ digital yet.
    I have had digital sat now for about 7 years, and terrestrial for about a year.
    As to range an signal to noise, I can get stations that I could only get
    with a lot of noise and some reflections too in analog, now as clear as glass.
    Really, only an inexperienced person would claim that composite PAL
    in _whatever way_ was better.
    And I know composite PAL better then many of you here, as I worked many years
    at the source,
    Even studio quality (directly from a PAL camera) has all sorts of artefacts,
    just where the right striped shirt.

    I say: Just buy a good digital set :)
     

  3. Hmm, all the pro cameras I know come out in RGB or YUV.

    Nobody in the professional world should be using PAL/NTSC in the
    studio's primary signal chain today


    martin
     
  4. Eeyore

    Eeyore Guest

    Interesting you should say that. There must be tons of gear out there that's
    'legacy' so-to-speak PAL.

    Graham
     
  5. I think you can still buy toy composite mixers, try BHphoto etc and
    the camera control units (CCU) all had the usual PAL ScH and timing
    adjustments, but rarely used, and don't forget that the (almost
    obselete) Betacam SP format recorded in YUV anyway.

    The PAL outputs are great for preview monitors, ie non critical, and
    less wiring.

    PAL is a very robust transmission format, but absolutely sucks in a
    production setting


    martin
     
  6. No it is crap.

    < In the UK,

    YUK

    Yea, well known, BBC, before it went brain dead, used to make nice pictures,
    even had in the very old ages 4 tube cameras, I have been there, touched them,
    had some interesting discussions with their techies.

    Whatever you may think, compared to digital it sucks.
    And that is digital done the right way, it makes no sense to
    compare bad digital to HQ studio analog PAL as you do here when you talk
    about some cheapo unspecified piece of consumer quality, about
    some unspecified channels, sure you can get it as bad as you like.


    Now that sure counts as a professional test.

    Morons.

    BYE
     
  7. clifto

    clifto Guest

    Really? Could I have a model number and manufacturer? Every source I've
    seen says that to date there is absolutely no such thing in existence,
    and is pessimistic about the appearance of such before the deadline
    and/or at a price anywhere near the ridiculously low projections for
    price of such items.
     
  8. Well, tehre are some channels 9I can tell you as ican get all UK stuff here too
    via satellite, tha tis ITV1-4 BBC- Parliament (if that is a channel), many more,
    and soem of teh FTA Ky.

    I have __***NEVER***__ seen 'noise stop', that is actually a sign of your
    decoder not keeping up, I have noticed that some Sky channels transmit in
    352x288 (the set will scale it to full) so at 1/4 the bandwidth, but you
    cannot blame that on the digital system!!!!!! Blame it on Rupert!!!
    You are not talking about a f*cking Skybox no?????????????????

    Exactly, there is, if you have a PCI card, some Linux program that shows
    all the bitrates for the various streams in the transponders.
    Cannot remember the name of the program, there are hundreds of utilities.

    Sure, I do not question the observation, but I do say you need to compare
    GOOD digital with GOOD PAL composite, else comparing makes no sense.

    I
    Yes those pople may exist, but normal people would return the set.
    That is why I am using a PC, no matter how they encode it, I will find
    some decoder.

    The public will keep buying new stuf fevery standard change say maybe even
    more often then the lead-free requires.
     
  9. On my PC I have voice control, I can just say:
    show BBC1
    show ITV1
    show ARD
    show RAIuno

    and in a second or so (as the motorized dish moves to a different sat)
    I have it on the 1680x1050 LCD (no not yet 1980).
    All it needs is a PCI card and a satellite dish.

    Your granny could do it, if she could find the power button on the PC
    and monitor.


    You can find the scripts on my website (Linux of course).
    http://panteltje.com/panteltje/dvd/index.html
    login with user 'guest' and password 'none' without the quotes.
    http://panteltje.com/panteltje/dvd/show
     
  10. clifto

    clifto Guest

    MORE reliable? Please elaborate.
     
  11. Eeyore

    Eeyore Guest

    You would perhaps (or not) be amazed how much critical stuff like editing (for
    feature films even- and I mean some really serious ones) is - or certinly was - done
    from rushes that arrive on Beta SP tapes.

    Given the huge investment in such kit I'd not be surprised if it's still quite
    common.

    Graham
     
  12. Chris Jones

    Chris Jones Guest

    Actually I think you may be speaking some truth there. In the UK, the video
    bandwidth of the analogue PAL signal is wider than in other PAL countries,
    which is why they had to move the sound subcarrier further from the vision
    carrier, and which is why TVs couldn't be taken to/from the UK from/to
    other PAL countries without some re-tuning, until multi-standard chipsets
    were introduced. It is very likely that he has never seen a PAL signal
    with as much resolution as we get in the UK.
    Yes, I borrowed a digital PVR from a friend and was not at all impressed. I
    don't like it when the numerical noise sometimes stays still and sometimes
    moves. If they had not tried to cram so many channels of crap into the
    bandwidth then they could have made it as good as the analogue system.
    It's not like they have enough worthwhile programmes to fill even the
    analogue channels, so they could have afforded the bandwidth.

    Chris
     
  13. Chris Jones

    Chris Jones Guest

    Of course there is DVB-T in the UK, that's why we know from personal
    experience that it looks worse than the old UK PAL system, that admittedly
    does have a wider video bandwidth than what you would have been used to.
    Perhaps they have throttled down the bitrate per channel in the UK to less
    than they use where you are. I would like to see the numbers.
    Or just someone who has seen both pictures and then tells the truth. I
    suspect that many people who have just spent a couple of grand on a new TV
    feel that they have to say it looks better, because otherwise that would
    make them stupid - so it's like the emperor's new clothes.
    The more recent PAL TVs have fancy FIR comb filters that fix most of that
    stuff. It is certainly less intrusive than the DVB-T artefacts, like noise
    that freezes and then jumps and then freezes again.
    And then buy another one when they switch to MPEG-4, which they have already
    proposed doing. Well by then it will have failed from tin whiskers anyhow.

    Chris
     
  14. Chris Jones

    Chris Jones Guest

    I would like one which simultaneously decodes ALL OF the four main channels
    (BBC1, 2, ITV, CH4) and then re-modulates ALL of them as PAL onto different
    UHF frequencies, to basically recreate the old analog spectrum (albeit with
    some MPEG artefacts...). I want one of these because I'm pretty sure that
    I won't find a set top box that is as easy for my grandmother to use as the
    four-position rotary switch that is on her present TV, and I don't want it
    to be harder to use when the analogue transmitter is turned off. I think a
    box like that would sell very well even for a high price, to the elderly or
    basically to anyone who can't get that excited about a new modulation
    method like these fanboys, but who just wants to watch TV. Perhaps when
    the time comes I'll just have to buy 4 digiboxes and some splitters and
    combiners and make one of these boxes. At least then all her elderly
    neighbours could use it too, at the same time, so it might work out cheaper
    as well.

    Chris
     
  15. The reason that one might speculate this is that PbF solder has a higher
    melting point and is harder, thus perhaps less prone to thermal damaged due
    to cycling. This might be the case IF done right, but there are so many
    variables that it is impossible to generalize this. The fact is that most
    in the field realize that it is much easier to get it right with leaded
    solder, and it is generally considered to be more reliable for most
    applications. In fact, there are exemptions for critical applications that
    allow leaded solder, even in the EU. The biggest problem that I have seen
    in consumer electronics with PbF is that not enough solder is deposited in
    the automated process of making the boards. This aften leads to an
    unreliable joint. It is also harder to get good results in repairs with
    PbF, as it requires higher temperatures and even the most freindly
    formulations do not wet and flow as well.

    Leonard
     
  16. Chris Jones

    Chris Jones Guest

    And then just when it gets to the interesting part of the programme you're
    watching, outside it start raining. Then you get a few splutters of choppy
    audio and a blue screen, then nothing at all, and you have to wait for it
    to be repeated on analogue tomorrow.

    Chris
     
  17. Chris Jones

    Chris Jones Guest

    Well I agree that there is no theoretical reason why the fact that the
    signal is digital necessarily makes it look bad, for example the PAL
    pictures that I have been watching were probably processed in the digital
    domain through most of the signal chain before transmission.

    What I am comparing is the end-user experience of watching a consumer grade
    DVB-T receiver (in my case a Pioneer decoder), when compared to a
    consumer-grade PAL receiver. In the end, if the picture quality is worse
    USING THE EQUIPMENT AVAILABLE TO CONSUMERS, then that is all that counts.
    I realise that a digital system with 300Mbits per second could be much
    better than PAL, but what is being given to us is NOT better than PAL. By
    all means they could build a good digital system, but that is not what this
    is about. It is about freeing up as much spectrum as possible for auction,
    whilst enabling the maximum number of channels of adverts to be transmitted
    with a quality that is just good enough not to cause a backlash that would
    result in people just turning off and watching a DVD.
    But surely you don't dispute that the channel bandwidth here is wider than
    what you used to get?
    Well you just go and sit in your studio and watch your test cards then.
    What actually matters is the picture quality that people (don't) get in
    their homes.
    Whatever.
     
  18. Chris Jones

    Chris Jones Guest


    Thank you, that's helpful.

    I still think it might not be for grandmothers, e.g. explaining why you
    can't just unplug it when you're finished watching, etc. It would take me
    a day of driving to go and replace a failed HDD, and whilst the local TV
    shop can happily repair the analogue TV set, they might not be so hot on
    reinstalling perl scripts. At least the start-up time would not be
    unfamiliar, it would a reminder of waiting for the valves to warm up in the
    set before the present one (which was still working when it was scrapped,
    but it was 405 lines and B/W).

    Chris
     
  19. Arfa Daily

    Arfa Daily Guest

    Of COURSE I have digital, foolish person. That is how I am able to comment
    on this. I have had analogue satellite since it was first available as DBS,
    and I changed over to digital as soon as that became available. I also still
    take analogue from the terrestrial transmissions, and carry out repairs to
    digital terrestrial STBs as part of my living, so I am able to compare all
    standards at all times. I feed signals around my house at UHF, and have
    perfectly clean signals at every TV - and there are a lot of them. As far
    as HDTV signals go, they just about manage to get back up to the standard of
    a *good* analogue transmission. As far as your opinion of my being
    inexperienced goes, I have been directly involved with this stuff from the
    service angle for 37 years. If that makes me 'inexperienced' in your eyes,
    sobeit.

    As for beat interference atrifacts from tweed jackets and loud ties, this
    has not been much of a problem for years, since people in studios were
    dressed properly for the job. Even so, I would still rather see a 'busy' tie
    on a newsreader, than motion artifacts - both edge pixelation and motion
    blur - any day of the week.

    It's all very well saying that compression artifacts are a product of
    available bandwidth, but that bandwidth is much limited with terrestrial
    digital, if you want to pack in the number of channels that they seem to
    want to. This allows for a perfectly satisfactory picture so long as it is
    standing still, but does not if the bitrate needs to go up high enough to
    prevent motion artifacts. For the most part, however, I would agree with you
    that this is not an issue with the satellite transmissions, where the
    limiting factor becomes how good a transponder, bit rate-wise, the station
    can afford to lease.

    Make no mistake, I am not trying here to compare a good digital signal - say
    Sky Movies Premiere - with a poor noisy anlogue signal. What I am saying is
    that the general public is being 'sold a pup' with the digital terrestrial
    channels, where even the best quality transmissions, struggle to produce a
    picture subjectively as good as that produced on a *good* analogue TV with a
    *good* analogue PAL signal going in.

    Arfa
     
  20. Arfa Daily

    Arfa Daily Guest

    I fear it is you who is the moron, my friend. It makes absolute sense to
    compare a crap digital signal to a good analogue one, for the ones provided
    by digital terrestrial are, for the most part, crap. This is in stark
    contrast to the analogue terrestrial signals, which have always been of the
    highest quality. The opinion of the poster on what he saw on a PVR, was not
    intended to be seen as a 'professional' test, rather it was a subjective
    test, which is what we have been talking here all along ...

    Arfa
     
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