How to pull HDMI or Cat6 using existing hidden Sky coax cable route to dish?

[MasterMark]

Hello all! Apologies for the length of post, but figured it was best to describe everything.Any tips/suggestions would be massively appreciated!

So, historically had Sky HD, with a RF/Coax cable chased through the wall so I could watch the same channel in the kitchen. Kitchen & lounge are open, but I can't see the tv from the kitchen so with an additional small tv in the kitchen, perfect way to watch while cooking and move seemlessly betwee the two.

I've now made the mistake of upgrading to Sky Q I've tried with an HDMI splitter and a long 15m HDMI cable. Works absolutely fine. But I can't use the existing cable routing because they didn't use a conduit and the cable is cemented into the back-box, and despite my best efforts, I can't loosen it.

So another option - Sky coax cables currently run hidden (i'm guessing under skirting boards) to the dish just outside the lounge (on the wall off a flat roof, so easily accessible). It's about a 5m run. So I guess 2 questions:

1) What is the best way to pull and HDMI or Cat6 cable through? I guess I'd need to tape it to the existing Sky coax, then pull everything through from the outside, and then try and pull the coax cables back in? If I get the (waterproof) cable outside, I can run it for another 5 or 6 metres and drill a hole straight into the kitchen.

2) Assuming I can actually pull and HDMI through (hoping it's not too thick), am I better off using HDMI splitter and 15m HDMI cable, or running a Cat6 with HDMI extender/Baluns on either side? Amongst other things, wondering there'd be any difference in terms of sound/picture lag given I can "hear" both TVs. Just HD, not 4K.

Thank you for any tips!

 

[noiseboy72]

I think it highly unlikely that you will be able to pull new cables in if the current ones are just run in behind the skirting boards. If they were not pulled in originally, but laid in and boxed, there could well be pinch points and sharp corners you won't be able to pull around.

You better solution might be an HD modulator to send the Sky Q signal using your existing co-ax cable. Downside is there will be a slight delay - which may mess you up in terms of lip sync with the audio for your remote TV.

Something like this: Amazon product

 

[MasterMark]

Thanks, Noiseboy! I had looked at those modulators actually, but the delay makes it a non-starter unfortunately. Also at that price point, it would be cheaper to just remove the skirting boards, install a new cable run and install new skirting.

In your opinion, if I went down that route, would 15m HDMI or HDMI over Cat6 be a better solution, or little to choose between them for my purposes?

 

[noiseboy72]

Depending upon the Cat6 / HDMI adapters used, there may still be some delay. The solution is likely to be more robust and future proof, as 15M HDMIs are on the limit for HD and usually a non starter for 4K. This may affect you if you are trying to send 4K to your main TV, as unless you invest in a scaler to send different resolutions at the same time, you may want to send 4K to your kitchen TV.

 

[MasterMark]

Thanks! I've actually noticed an (incredibly slight) delay, in the milliseconds I think, using the 15m HDMI. I can correct that through the tv, so not an issue. I will experiment with cat6 to see if there's any difference, but as you say I may as well future-proof it even if I don't have 4k now. For what it's worth, the 15m HDMI (cheap and cheerful, £15) seems to be be working perfectly which was a little surprising given the length.

 

[noiseboy72]

There will not be any delay due to the cable itself. 15M length with signal moving at 186 000 miles per second is as close to instantaneous as you can get!

Delay may be due to the processing of the HDMI signal in the TV, but I would have thought this would be very similar to the HDMI input in most cases.

 

[MasterMark]

Hahaha, ok the cable is definitely NOT the reason for the delay then!

Thanks for all your help, much appreciated!

 

[Rodders53]

Can anyone comment on $ky Q minis (multiroom) and watching same thing - I suspect they're unlikely to be in sync either? Probably not a cheap solution, either.

The cheapest and quickest solution is likely to be careful removal and replacement of skirtings to run alternative cabling.

RF speed in cable is slower than speed of light in free space, including fibre optics. (x0.87 factor for coax). Trivial delay over short distances in the home - certainly not noticeable and not even easy to measure - but it needs accounting for in some (broadcasting) applications where synchronous operation is important.

 

[MasterMark]

Hi Rodders, I actually tried the Q mini box - the sound/image delay there was probably 2-3 seconds, so unfortunately totally useless for my purposes. Seemed to work well as a "proper" multiroom solution though.

 

[MasterMark]

As for the Cat6, I think I must be very thick about how the connections work.

Receiver end - HDMI balun connected to the 2nd tv with HDMI cable. Cat6 cable plugged in and connects to the Transmitter End (Main TV Sky Q end).

Transmitter end - given the Sky Q box only has 1 HDMI input (connected to the TV) and no HDMI output, how do I connect the HDMI Balun?! Do I still need am HDMI splitter?

 

[noiseboy72]

Yes, you will need an HDMI splitter. As I say, when connected, it will limit your maximum resolution to the lowest quality TV and / or cat 6 baluns.

 

[MasterMark]

Aaah, ok, so I need both the HDMI splitter (which I had originally used to connect directly with the 15m HDMI cable) AND the additional HDMI cat6 extender. Cheap and cheerful one I bought below.

Amazon product