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Thread: PAL tuner info request

  1. #1

    PAL tuner info request

    I've been looking at the work you guys have done and I'm well impressed. It got me thinking about the possibilities of a Freeview/digital tuner mod. Looking at these Freeview boxes:-

    http://www.inest.co.uk/products/Tevi...rt_Adapter.asp
    http://www.willentrading.co.uk/visio...hmit48pa9327pf
    http://www.securitydirect.co.uk/acat...x_Compact.html

    made me realise that the decoding electronics can be quite compact with modest power requirements. So what I'm visualising is removing the existing analogue tuner and being able to replace it with a tuner and compact decoder (with simplified firmware as the EPG, etc would be redundant) that can then be connected into the Tivo motherboard (with wires so we don't have to worry too much about dimensions). If its done right the Tivo would be able to switch channels directly (not via infra-red) and the decoded output would be fed directly onto the motherboard. And with a bit of luck it would pick-up its power off the motherboard too.

    I've seen references to the Alps tuner specs but I can't find them. Can anyone help me out? Some of the pin-out abbreviations I can decode (power, channel switching, etc) but others I'm less clear on so an explanation of those would be useful.

    Also can a Tivo still work OK with the tuner removed?

    Thanks

    Paul

  2. #2
    Join Date
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    Quote Originally Posted by roman View Post
    Looking at these Freeview boxes:-
    You don't specify in your profile where you are located. If you are in the UK then those "Freeview" boxes will be OK. However if you are not in the UK please be advised that "Freeview" UK is not the same as "Freeview" in Australia. For starters UK uses UHF band only so these boxes won't have the ability to tune into VHF stations that the majority of Australian capital cities are on.

    So what I'm visualising is removing the existing analogue tuner and being able to replace it with a tuner and compact decoder that can then be connected into the Tivo motherboard (with wires so we don't have to worry too much about dimensions). If its done right the Tivo would be able to switch channels directly (not via infra-red) and the decoded output would be fed directly onto the motherboard. And with a bit of luck it would pick-up its power off the motherboard too.
    It's been done already. Some people successfully used a compact digital STB made by Thompson a while ago and either fed the video out of that into the rear video input socket or even got adventurous and removed the existing tuner module and fed the video into this point. Control was still via IR but I am a little confused as to your proposal because your method would still need an IR signal to switch channels (the boxes you list all still need IR for channel change) or at the very least some kind of translator to convert the TiVo I2C tuner control signals to something your digital tuner can understand.

    (with simplified firmware as the EPG, etc would be redundant)
    Why? The whole reason people like TiVo is for it's EPG. To remove the EPG makes a TiVo no better off than a sub-$200 single tuner STB with hard disk.

    You also do realise that what you are propsing still is essentially connecting up an external digital STB but somehow you want to control the channel switching via the TiVo I2C bus signals rather than the IR Blaster?

    It will still be an analogue video output from the digital decoder that is again digitized into SD only MPEG for recording on the hard disk. It is still only a single tuner and the ability to record one video stream.

    Also can a Tivo still work OK with the tuner removed?
    Sure can.
    Darren King
    OzTiVo Repairs and Modifications
    If your TiVo requires repairs or modifications
    then visit: http://kingey1971.wix.com/tivorepairs

  3. #3
    Join Date
    Dec 2005
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    Quote Originally Posted by Darren King View Post
    Why? The whole reason people like TiVo is for it's EPG. To remove the EPG makes a TiVo no better off than a sub-$200 single tuner STB with hard disk.
    I think he means the EPG broadcast with the video stream.

    Darren did you ever manage to source any replacement PAL tuners for the Samsung tuners in the S2 DT units? Pointless now that the TiVoHD is available, but just curious as I have one in the cupboard.

    TiVo Series3 TiVoHD x2

  4. #4
    Hi Darren,

    Thanks for the reply. I am aware that your digital equivalent to our Freeview have some differences with ours. But broadly speaking its a number of groups of channels broadcast across a group of frequency bands. A Freeview box tuner then tunes into one of those bands and additional circuitry then decodes the specific channel from the multiplexed data stream on that band. The resident firmware provides an interface for displaying the EPG, OTA updates, etc. I've probably grossly over-simplified and feel free to correct me if my understanding is faulty.

    Skolink is correct. For the idea I'm looking at the Freeview EPG and a lot of the other functionality in a typical set-top box firmware is pointless. All I want is something that can tune and decode Freeview channels and feed the result to the host Tivo which as you rightly point out has a far superior interface and EPG.

    Some people successfully used a compact digital STB made by Thompson a while ago and either fed the video out of that into the rear video input socket or even got adventurous and removed the existing tuner module and fed the video into this point.
    That sounds like the kind of thing I'm looking at. Any info, howto's or photos? This why I'm interested in the pin-outs for original Alps tuner.

    Control was still via IR but I am a little confused as to your proposal because your method would still need an IR signal to switch channels (the boxes you list all still need IR for channel change) or at the very least some kind of translator to convert the TiVo I2C tuner control signals to something your digital tuner can understand.
    That might not be insurmountable given the some of the things that have been achieved like sound module on the Mark 1 PAL conversion or the Cachecard.

    You also do realise that what you are propsing still is essentially connecting up an external digital STB but somehow you want to control the channel switching via the TiVo I2C bus signals rather than the IR Blaster?
    I think it would be a much neater and less error-prone if it was all built into the Tivo.

    It will still be an analogue video output from the digital decoder that is again digitized into SD only MPEG for recording on the hard disk. It is still only a single tuner and the ability to record one video stream.
    Isn't this what currently happens when we feed a Tivo from an external set-top box? If it was built-in there'd shorter paths, fewer connections and a neater setup under the TV

    So! Can anyone help me out with the specs/pin-outs of the Alps tuner?

    Thanks

    Paul

  5. #5
    Join Date
    Apr 2005
    Location
    New Zealand
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    The tuner details can be found here:
    http://www.oztivo.net/oztivofiles/ha...ner/B0206C.pdf
    and here:
    http://www.oztivo.net/twiki/pub/Hard...taSheets/S.pdf

    Hope this helps.

    Just a thought - has anyone found a 'freeview' tuner that could replace the Alps?

  6. #6
    Join Date
    Mar 2005
    Location
    Hamilton, NZ
    Posts
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    Serial Control

    There are a couple of people who have used modified serial commands to control a STB without having to use the IR blasters:

    http://oztivo.net/twiki/bin/view/Sof...ialPortControl

    http://forums.oztivo.net/showpost.ph...0&postcount=10

    Just another approach to consider

  7. #7
    Thanks Islander, I've already got those. But as their not pin-compatible with the original UK Alps tuner they don't cover what I'm after which is info/specs on the original tuner. Or a UK Tivo motherboard schmatic/spec that tells me what each of those pins do.

    Thanks Catdog. Something to keep in mind

    Paul

  8. #8
    In the PDF called:-

    "ALPS_TMDG2_tuner_howto_v4"

    it says

    "I have included a basic PDF datasheet on the ALPS tuner in the archive
    this document came in for anyone interested."

    The PDF didn't come in an archive. I got it from:-
    http://www.oztivo.net/twiki

    and I can't find the Alps tuner datasheet anywhere on there.

    Can anyone please help?

  9. #9
    Join Date
    Dec 2005
    Location
    Christchurch, New Zealand
    Posts
    463

    TMDG pinout

    Maybe this is what you are after? It doesn't have much detail though.
    http://www.oztivo.net/twiki/pub/Uplo..._TMDG-TMDB.pdf

    TiVo Series3 TiVoHD x2

  10. #10
    Ah! Thank you. That's just what I was after.

    It doesn't have much detail though.
    Its a good starting point, essential even.

    Thanks,

    Paul

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