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-   -   General : Power Levels? (https://www.cableforum.uk/board/showthread.php?t=33701417)

chambohambo 19-09-2015 20:26

Power Levels?
 
Hi,

How do my power levels look on my superhub 2? I have a strange issue were all 8x downstreams can be around 0 and my 2x upstreams around 48-49 which is normal, as you can see from below the downstreams are around -3 and the upstreams are around 54, can someone explain to me what causes the upstream and downstream to change like that, I have checked all the connections myself and they are firmly tight.

Tivo power level for upstream is also 54, just checked now 21:45 and it dropped to 52 and now 21:51 it has gone to 57, superhub 2 is still at 54 at this moment.

Update 22:13

Tivo power level for upstream is now 48, superhub 2 is 52.75 and 53.50.

Thanks for looking at my post.


Downstream
DS-1 DS-2 DS-3 DS-4 DS-5 DS-6 DS-7 DS-8
Frequency (Hz) 275000000 251000000 259000000 267000000 283000000 291000000 299000000 307000000
Lock Status(QAM Lock/FEC Sync/MPEG Lock) Locked Locked Locked Locked Locked Locked Locked Locked
Channel ID 4 1 2 3 5 6 7 8
Modulation 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM
Symbol Rate (Msym/sec) 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17
Power Level (dBmV) -2.81 -3.56 -3.00 -2.75 -2.86 -3.09 -2.99 -3.05
RxMER (dB) 37.94 37.09 37.36 37.64 37.94 37.94 38.26 38.26
Pre RS Errors 1502 1648 1409 1157 1048 946 1025 976
Post RS Errors 1046 1035 991 826 694 691 772 747


Upstream
US-1 US-2 US-3 US-4
Channel Type 2.0 N/A N/A 2.0
Channel ID 34 N/A N/A 33
Frequency (Hz) 35800000 N/A N/A 45800000
Ranging Status Success Other Other Success
Modulation 64QAM N/A N/A 64QAM
Symbol Rate (Sym/sec) 5120000 N/A N/A 5120000
Mini-Slot Size 4 N/A N/A 4
Power Level (dBmV) 54.00 N/A N/A 54.00
T1 Timeouts 0 0 0 0
T2 Timeouts 0 0 0 0
T3 Timeouts 0 0 0 0
T4 Timeouts 0 0 0 0

General Maximus 20-09-2015 07:39

Re: Power Levels?
 
the weather for started. I wouldn't worry about your downstream atm, mine are all -2 to -4 and my connection is fine. That being said, my upstream channels are 45 and 54 is defo too high for you. Out it out of spec on qam16 and defo for qam64. I wouldn't worry about your TiVo too much, from what I have seen in the past tivos have always had a higher upstream and seem to be more tolerant. You can leave as it is atm but if you start seeing problems I would make a phone call because it can be easily fixed.

chambohambo 20-09-2015 08:21

Re: Power Levels?
 
Hi,

Thanks for replying to my post General Maximus.

What would need to be done to fix this high upstream, I had a problem like this last year the engineer moved me up a tap I was on the 29 tap point then got moved up to 22 tap point.

This morning the superhub 2 power levels for the 8x downstreams -2.90 -3.46 -2.91 -2.65 -2.84 -2.99 -2.93 -3.05 and for the 2x upstreams 51.75 and 53.00, and the tivo upstream is 48.

I have also noticed in the past couple of years in my area some green cabinets have had extensions attached them, what are they?

Sephiroth 20-09-2015 16:07

Re: Power Levels?
 
The 22 tap point would lower upstream power from what it was on 29dB.

Anyway, with high upstream power when the downstream is normally low indicates a difficulty being read properly by the CMTS. I'd assume nothing wrong with your modem; there may be something noisy or breaking down in the local cabinet but I doubt it. There may be noise on the optical node (tired lasers or summat). You are at 64QAM so there's less tolerance for noise. Could be noise ingress. Could be anything.

Igni usually knows the likely causes of high upstream power.

chambohambo 21-09-2015 17:51

Re: Power Levels?
 
Hi,

Thanks for replying to my post Sephiroth. I will wait and see if Ignitionnet responds to my post.


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