Rearranging V+ and Tivo boxes, modem and splitters. OK?

Spookytooth · 20-09-2012, 18:03

Currently my set up is:

Cable from outside to isolator in lounge: short cable to splitter. One branch goes to modem (and router etc) upstairs (50m), other branch goes straight to second splitter in lounge. From there, one branch goes to V+ Box in lounge, other branch goes to Tivo Box in kitchen (25m). All installed by Virgin engineers.

I want to move the boxes around a bit as follows:

V+ and Tivo boxes to stay where they are, modem and router to move next door to kitchen. Using same splitters, the wiring becomes:

From isolator direct to splitter in lounge (as now). One branch direct to V+ Box in lounge. Other branch 25m to splitter in kitchen. One branch goes straight to Tivo box in kitchen, other branch to modem in next room.

As things currently are therefore the modem gets half the signal, the V+ and Tivo a quarter each. As rearranged, the V+ will get half, the Tivo and the modem a quarter each.

Will the above work OK (assuming the splitters are identical)?

jb66 · 20-09-2012, 20:31

What's your modem power levels on your modem? 192.168.100.1

Spookytooth · 20-09-2012, 20:39

Thanks for your reply

Upstream 47.2 dBmV
Downstream 2.8 dBmV

jb66 · 20-09-2012, 20:57

Yeah should be fine, your upstream will rise to 51 and your downstream will lower to just below 0 so both are within correct levels

Spookytooth · 20-09-2012, 22:53

Thanks a lot, you saved me Â£99 (or whatever Virgin's callout is)!

Spookytooth · 23-09-2012, 11:39

I made all the rearrangements as above and everything works fine. Your power level predictions were pretty much spot on.

One further question if you don't mind: there is an isolator where the cable first enters the house, and a further one where, having been split once and left the house, the cable re-enters. It doesn't run underground, just around the outside walls.

Will two isolators in series affect my broadband? Speeds seem ok but ping (in games) perhaps slightly off, though only slightly.

jb66 · 23-09-2012, 12:05

It doesn't affect your bb performance, it's required In case of a power surge so please don't remove them

Spookytooth · 23-09-2012, 20:34

I do understand the purpose of an isolator, but I would have thought just one, where the cable first enters the house, would have been sufficient?

jb66 · 23-09-2012, 20:42

But it leaves your house and goes in again, I suppose a lightning strike is a possibility

Spookytooth · 23-09-2012, 22:38

Not very likely, but leaving that aside, what might the effect of two isolators in series be? Even if I don't plan to remove either, I would be interested to know.

jb66 · 24-09-2012, 06:15

It will loose 0.4db of signal on the upstream and downstream, its just like adding a piece of cable

Spookytooth · 24-09-2012, 09:19

OK thanks for your replies, appreciate you taking the time and trouble to advise.

Jonnymeg · 28-09-2012, 18:31

The point of the additional isolator is to protect your kit from each other as well as the network, therefore one surge from device will not knock out the others.
In an ideal world there should be an isolator for each individual piece of CPE (modems & STBs).