TiVO Box Removed - Should I Remove Splitter?

[Naylor2006]

Hi all.

Quick question, as I understand it every join, splitter or coupler in the path will add in some sort of noise so now that we are a Broadband only customer with our TiVO box removed should I remove the splitter and plug directly into the Hub 3.0 instead to improve signal as our signal isnt perfect althought mostly fine....will removing the splitter have a beneficial effect? 

For context the the Virgin media wall socket has one metal old square box in it which the outside feed connects to,  this metal box one has one outlet, so the signal is not split there, there is then one cable from the wall box that goes into a splitter which splits to TV and Modem, it is this splitter I was wonder if I could remove so I just have the one cable going straight to the modem?

Thank you.

[Adduxi · Accepted solution]

If the TV output does not have a termination cap it could introduce noise. Best to remove it if not.  Just check the power levels afterwards as the splitter will have had a small impedance value. 

[nodrogd]

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@Naylor2006 wrote:

Hi all.

Quick question, as I understand it every join, splitter or coupler in the path will add in some sort of noise so now that we are a Broadband only customer with our TiVO box removed should I remove the splitter and plug directly into the Hub 3.0 instead to improve signal as our signal isnt perfect althought mostly fine....will removing the splitter have a beneficial effect? 

For context the the Virgin media wall socket has one metal old square box in it which the outside feed connects to,  this metal box one has one outlet, so the signal is not split there, there is then one cable from the wall box that goes into a splitter which splits to TV and Modem, it is this splitter I was wonder if I could remove so I just have the one cable going straight to the modem?

Thank you.

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The wall socket contains a safety isolator. This is similar to a fuse in an electrical plug, & prevents equipment from being damaged by electrical surges down the cable. These have very little insertion loss & will have no effect on your levels. Removing a splitter & any cable attached to it is more likely to affect your levels. They do not introduce noise, which only comes from incorrectly fitted or wrong specification cables & connectors leaking RF from outside. Splitters have an insertion loss of around 3.5dB, & if your levels are high may result in an adjustment at the cabinet being required to compensate for removal. The closer you are to the street cabinet the more likely you are to have problems if you make alterations.

[Naylor2006]

I removed it and my Downstream power went up to 11 which I believe 10 is the max! It also reduced my upstream power so ive had to put it back on but now I need to terminate it, doesnt seem like alot of point bringing VM out to adjust levels when I can just terminate.

Would you be able to point me in the direction of how to get hold of a termination cap because I have definitely seen more Pre RS errors and Post since removing my tiVO box today!

Edit: Just got some off amazon, 75 Ohm terminator cap, not coming till wednesday tho so will have to deal with the noise I guess!

[Adduxi]

Yes, that's the one.  75 Ohm cap and easy to fit.  Range for Downstream is -6 to +10 and Upstream 34 to 51 btw.  Maybe you could do with a 6dba Forward Path Attenuator?

[Naylor2006]

My current stats are as follows, Router was last reset around 1530 yesterday, so these numbers are all since then up until this post:

Interestingly the downstream acquired hz has changed from 331000000 to 139000000, I wonder what this means?

Cable Modem Status
Item	Status	Comments
Acquired Downstream Channel (Hz)	139000000	Locked
Ranged Upstream Channel (Hz)	36599981	Locked
Provisioning State	Online

[Naylor2006]

Downstream bonded channels
Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
1	139000000	6.3	40	256 qam	1
2	147000000	5.5	40	256 qam	2
3	155000000	5.4	38	256 qam	3
4	163000000	5.5	40	256 qam	4
5	171000000	6	40	256 qam	5
6	179000000	6	40	256 qam	6
7	187000000	6.4	40	256 qam	7
8	195000000	6	40	256 qam	8
9	203000000	6	40	256 qam	9
10	211000000	5.8	40	256 qam	10
11	219000000	5.8	40	256 qam	11
12	227000000	4.9	38	256 qam	12
13	235000000	5	40	256 qam	13
14	243000000	5	40	256 qam	14
15	251000000	4.6	40	256 qam	15
16	259000000	4.5	40	256 qam	16
17	267000000	5.6	40	256 qam	17
18	275000000	5.4	40	256 qam	18
19	283000000	5.8	40	256 qam	19
20	291000000	6	40	256 qam	20
21	299000000	5.6	40	256 qam	21
22	307000000	6	40	256 qam	22
23	315000000	6.1	40	256 qam	23
24	323000000	6	40	256 qam	24

[Naylor2006]

Downstream bonded channels
Channel	Locked Status	RxMER (dB)	Pre RS Errors	Post RS Errors
1	Locked	40.3	48	0
2	Locked	40.9	38	0
3	Locked	38.9	35	0
4	Locked	40.3	43	0
5	Locked	40.3	33	0
6	Locked	40.3	50	0
7	Locked	40.9	48	1
8	Locked	40.3	51	0
9	Locked	40.9	69	0
10	Locked	40.3	42	0
11	Locked	40.3	32	0
12	Locked	38.9	95	0
13	Locked	40.9	102	0
14	Locked	40.3	115	0
15	Locked	40.3	156	0
16	Locked	40.3	151	0
17	Locked	40.3	45	0
18	Locked	40.3	49	0
19	Locked	40.3	37	0
20	Locked	40.3	44	0
21	Locked	40.9	634	0
22	Locked	40.3	542	0
23	Locked	40.3	493	0
24	Locked	40.3	600	0

[Naylor2006]

Upstream bonded channels
Channel	Frequency (Hz)	Power (dBmV)	Symbol Rate (ksps)	Modulation	Channel ID
1	36599981	35.8	5120	64 qam	3
2	30100000	35.8	5120	64 qam	4
3	43100034	36.3	5120	64 qam	2
4	49600269	36.5	5120	64 qam	1
5	23599986	35.8	5120	64 qam	9

Upstream bonded channels
Channel	Channel Type	T1 Timeouts	T2 Timeouts	T3 Timeouts	T4 Timeouts
1	ATDMA	0	0	0	0
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0
5	ATDMA	0	0	1	0

[Naylor2006]

Just the one t3 time our and post rs error, not sure what is generally acceptable but ive not noticed this and neither turned up as complete drops in BBM