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.

[Z92]

I don't see how it's a dangerous problem, and since I don't have a V6 box I don't need a £500 optical HDMI cable.

In fact I don't have a HDMI cable at all, I watch Sky TV and Netflix without any boxes as everything needed is built into my TV. I do have an optical SPDIF cable from my TV to my audio system however.

VM simply provide the broadband necessary.

[Richw1982 · Accepted solution]

The set up you have is the same setup that thousands of people have, and is correct to the latest regulations.  You never answered if it was a FTTP or FTTC area.  If a FTTP area this is fibre to your property and no way of electricity travelling from cab to CPE

[asha_bristol]

No, it comes through coax under the garden lawn. This is what I don't understand:-

A galvanic isolator seperates the ground signal of the coax thus preventing ground loops. So if I'm getting ground loops it must be because there is no galvanic isolator or if there is it's faulty / incorrectly installed. Is this not correct?

[Z92]

Your interference is most likely caused by the power inserter and not the incoming cable though.

[Richw1982]

So if your in an HFC area and have a power inserting isolator, I assume you have an HDU fitted which may be causing interference.  If you have a Electronic splitter/HDU what are your Power levels ( Upstream and downstream) to your hub.  You can get this info from the hub settings pages

[asha_bristol]

Downstream power: Lowest 6.9, Highest 8

Upstream power: Lowest 44.3, Highest 46

[Z92]

I'm guessing if you remove the HDU plug the levels are too low to obtain decent service, but I'm also guessing that would remove the hum?

[asha_bristol]

I could try that later when my wife finishes work.

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?

 

[Richw1982]

So if you have a 2 way HDU fitted it looks like there is an issue with the return path being too low (33 is the highest and 51 is the lowest it should be and is opposite to the forward path of 10 being highest and -6b being lowest)  If you took HDU off and put a genuine 2 way splitter in its place your levels would be around 3/4 downstream and 49/50 on upstream.  May require an engineer to check cab levels as with levels at +3 downstream ideally the return should be around 44-46 

[asha_bristol]

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.

Part of the problem is everything works great, good speeds, good ping, good jitter, all very reliable.

Do you know anything about the safety device my friend has fitted?

Would a galvanic isolator after the second amplifier / splitter be the answer then?