Position of Isolator in Set-up.

[asha_bristol]

Hello,

I am a bit confused about where in my set-up the isolator should be placed. I have a "power inserter" in my white box, which then goes to a powered splitter, which in turn feeds my V6 and modem - all in the same room.

I have tried to do some research online but it seems there are 3 different schools of thought as to what's best. So is it:-

1) An 'inline' isolator between the power inserter and the powered splitter?

2) 2 x 'inline' isolators after the powered splitter close to the end of the V6 and modem?

3) No 'inline' isolators, but instead a 'Fully Isolated System Outlet' between the power inserter and the powered splitter?

Which is the safest option to protect my expensive AV setup?

Thanks.

[Adduxi]

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@asha_bristol wrote:

A friend of mine has a 'safety device' just before the coax enters his V6 and again just before the coax enters his modem. Is this some sort of isolator?  Would that help me? <snip>

 

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That looks like the isolators used in the Quickstart packs.  Not sure if they would remove any mains interference from an HDU though.?

[Adduxi]

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@asha_bristol wrote:

Sorry, richw1982 but that reply is over my head somewhat. Whenever I've had to turn off the power to either splitter / amplifier the internet goes completely - i do know that much.  <snip>

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Most likely the HDU needs power to function, so I'm guessing that's why it stops allowing the circuit pass through.

I'm wondering if you powered off the HDU and connected the Hub directly to the incoming cable, what the power levels might be?  If they are within spec, as eluded to by Rich, maybe it could be removed completely and with it the mains hum?

Perhaps an engineer should visit and try various combinations with this and the taps in the Cabinet for getting good levels without the HDU?

[Z92]

That might work, but considering there's not a specific fault at the moment, it would likely be a £99 non-fault callout, which are cancelled at the moment due to covid!

Maybe the low signals are OK for just a hub, but when you have both a hub and a V6 on the line the levels are too low and that's why your signal goes down.

You could just try a CATV isolator at the back of your V6 box to see if it does anything (for £5 it's worth it). It's technically against the T&Cs but you could check the levels before and after, its a lot better than those people who have cut up and reterminated the coax themselves...

[asha_bristol]

Does anyone know what affect inserting an isolator just before the V6 box might have on signal levels?

[Z92]

It should state that on the device itself, and if you insert it before the hub instead you could actually measure it from the diagnostic pages on the web interface as a before and after.

[Richw1982]

Inline isolators loose 0.5db, if you could get hold of a 2 way 5-1218 or 5-1000 MHz splitter you could try this in place of the HDU, levels should be Downstream -6 - +10 and Return 33-51

[asha_bristol]

So is losing 0.5db by fitting an inline isolator going to make any noticeable difference to signal levels and the service I recieve or should my levels be able to handle the drop without issues?

I know 0.5db doesn't sound like much but I'm not sure in this context how it might affect things.

I've found an Asheridge gisx101 which has a typical insertion loss of 0.1db?

[Z92]

The levels you posted earlier will quite happily take a 0.5db loss.

But it's always worthwhile checking the levels in the hub interface after making any modifications to ensure everything is still working ok with no noticeable interference.

[asha_bristol]

Thanks, I think I'll try that first. If that doesn't fix it then maybe I'll look at replacing the hdu with a passive splitter as also suggested.

Richw1982 and Z92 - thank you for all your help.

[Z92]

Just remember that if you do have any problems in the future, remove the part you've installed before requesting any engineer so they can't blame it on that 🙂