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Coax splitter instead of loop through ?

Discussion in 'Audio Visual' started by jonm01, 11 Apr 2018.

  1. jonm01

    jonm01

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    I have a humax FVP5000t freeview recorder. This has to be left powered up for the tv loop through feed to work to feed the tv signal. I'd prefer to let it go into full standby mode, so to avoid losing the normal tv signal feed, is there any reason why I shouldn't use a good quality 2 way coax splitter and feed the box and the tv from the aerial to each? Thanks in advance.
     
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  3. Tigercubrider

    Tigercubrider

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    no.
    But both my Humax's have a loop through when switched off via the remote, and not when switched off at the rear switch.
    However, if switched off at the back, they have to reboot on startup and won't record on timer.
     
  4. winston1

    winston1

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    The only thing to bear in mind is that a splitter will have approx 4dB loss to each output. Won't matter with a good signal, but could in a weak signal area.
     
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  5. Tigercubrider

    Tigercubrider

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    I should add- a powered splitter/amp should be lossless
     
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  6. winston1

    winston1

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    But it will add noise.
     
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  7. jonm01

    jonm01

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    Further on to my original post, I've used a passive splitter and it's been working fine. Signal quality reads 100% on all channels, with signal strength 60 - 85% as measured by the humax. Picture reception seems fine with no deterioration. I just wanted to ask, if I decided to try the powered splitter option, could anyone advise, perhaps,please,on which particular makes are best ? Thanks
     
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  9. Lucid

    Lucid

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    Where you have 100% Signal Quality on all channels and Signal Strength ranging from 60 - 85% then you really do not need a powered splitter... at all... no way. You've pretty much nailed the perfect score with that passive splitter.

    Quality is by far the most important aspect of the Freeview signal. Strength isn't a big deal at all.

    Any powered splitter can add strength, but all that is in reality is the equivalent of loudness of signal. The thing with digital TV is once the signal strength is above a minimum threshold then nothing improves. In fact, throw too much amplification at a signal and you'll actually do some real damage to the Quality, and this is over and above the extra noise that an amplified splitter contributes.

    Quality, on the other hand, is a rare and fragile thing. There's only one place it comes from, and that's the aerial. Everything else in the signal chain either (at best) maintains it, or degrades it. Passive devices such as your splitter will do no harm to Quality. The cost is only a small loss in strength, and as long as there's sufficient strength to meet the minimum threshold plus a bit of a safety margin, then Strength really isn't that important. Amplified splitters add noise, and the result is a loss of Quality.

    Stick with what you have. There's no reason to change. All it will do is cost you extra money and make the Quality worse.

    If this or any other reply was helpful to you, then please do the decent thing and click the T-H-A-N-K-S button. It appears when you hover the mouse pointer near the Quote Multi-quote buttons. This is the proper way to show your thanks for the time and help someone gave you.
     
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  10. jonm01

    jonm01

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    Ok, good advice then, thanks! Out of interest, what's the lowest signal strength could go before it did become an issue ?
    Thanks again.
     
  11. Lucid

    Lucid

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    There isn't a level.

    If we use a 0-10dB adjustable amp, then even on the 0dB gain setting it will still add somewhere between 4 and 6dB of noise to the system. That means that the gap between the background noise and the signal level gets worse by 4-6dB. IOW, signal Quality gets worse by 4-6dB.

    To make sense of the dB figures, a 3dB loss means the signal gets halved. Another 3dB means half again; so 6dB of loss results in the signal being just 1/4 of the original level. That sounds dramatic, but on a decent aerial system we'd aim for a signal to noise margin of around 20dB at the aerial to then cope with some reduction as the signal travels through the system to the TV, so there's a bit of scope to play with.

    If this or any other reply was helpful to you, then please do the decent thing and click the T-H-A-N-K-S button. It appears when you hover the mouse pointer near the Quote Multi-quote buttons. This is the proper way to show your thanks for the time and help someone gave you.
     
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  12. winston1

    winston1

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    The signal level reading on your Humax is meaningless. There is no reference. 60-85% of what? Different manufacturers equipment will have different figures.
     
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  13. jonm01

    jonm01

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    Ok, thanks for the advice. It sounds more complex than I had thought! Will leave as is anyway.
     
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