Gorgo
join:2009-07-12
Hicksville, NY
| Transmit power at 54.0 dBmV
Greetings - I am seeing some pixelation on some of my iO channels and I assume it's from my levels being close to the edge. I live in a apartment building and have one cable coming in going to a 4-way splitter - 7dB loss right there.
Would a bi-directional amp help me in this sort of situation?
Many thanks.
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Here is the DOCSDIAG results for my cable modem - my set top boxes are in the same neighborhood - one is above 55 dB.
DocsDiag v030720 Copyright 2001-3 Robin Walker rdhw@cam.ac.uk
System up time = 1 days 21h 14m 02.00s
Ethernet carrier sense xmit errs.1 = 53
Ethernet other recv errors.1 = 8
Downstream channel ID = 13
Downstream channel frequency = 603000000 Hz
Downstream received signal power = 0.2 dBmV
Upstream channel ID = 3
Upstream channel frequency = 32000000 Hz
SigQu: Signal to Noise Ratio = 35.5 dB
Cable modem status = Operational
Upstream transmit signal power = 54.0 dBmV
Date and Time = 2009-07-12,15:20:46.0 |
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Tursiops_G
Technoid
Premium,MVM
join:2002-02-06
Norwalk, CT
clubs:
 ·Optimum Online
| Your Downstream power level is Excellent. Your problem is specifically with your UPstream signal... a Bi-Directional Amp is Not going to help you at all in this case, IMHO.
Most Likely, there is a problem somewhere in the 'Return Path' on your Cable Node...
Call CV, and place a Trouble Report for a "Max Transmit" issue, and have them do a truck roll to check your Signal Levels from your Cable Drop back to the "Tap" at the Pole...
-Tursiops_G.
--
If You're Unsure, "RTFM"... If You're SURE, "RTFM" Anyway.  |
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Gorgo
join:2009-07-12
Hicksville, NY | reply to Gorgo
Thank you for the tip. Much appreciated. |
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deez20
Premium
join:2001-07-12
Holbrook, NY | reply to Gorgo
But pixelation isn't going to be caused by high transmit. |
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Morbid Angel
Bitten By The Wolf
Premium
join:2002-12-12
Bethpage, NY
1 edit | reply to Gorgo
That can happen from using an amplifier. It helps the db's increase but it will increase transmit power and decrease the receive signal. At least that is what I remember what happens. If you do not have an amplifier then yea, the issue is most likely outside. Humidity is a biatch to my signal levels by my house. Everything works so much better in the winter. |
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Tursiops_G
Technoid
Premium,MVM
join:2002-02-06
Norwalk, CT
clubs:
·Optimum Online
| reply to deez20
said by deez20  :But pixelation isn't going to be caused by high transmit. Correct, but the High Transmit symptom may indicate the presence of a Defective Tap or Line Amplifier on the node, which can also result in Pixellation issues...
The Line Tech investigating the Max Transmit issue should be able to determine if there's anything else afoul with the Signal quality on that node.
-Tursiops_G.
--
If You're Unsure, "RTFM"... If You're SURE, "RTFM" Anyway. |
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PresRC
join:2002-01-19
Patchogue, NY | Do they charge for that line check? |
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Tursiops_G
Technoid
Premium,MVM
join:2002-02-06
Norwalk, CT
clubs:
·Optimum Online
| If the problem is with the equipment/wiring that is owned/installed by CV, then the Service call is FREE...
However, IF the problem turns out to be due to CUSTOMER-OWNED equipment/wiring, then there May be a Service Charge for the call.
-Tursiops_G.
--
If You're Unsure, "RTFM"... If You're SURE, "RTFM" Anyway. |
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PresRC
join:2002-01-19
Patchogue, NY | Does anyone know what signal levels Cablevision is required by specification to provide at the drop?
Is there a printed spec one can look at?
Thanks |
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anonname
@cablevision.com | reply to Gorgo
A 54 is within range and would not cause an issue. However there is another problem and you need to have someone come look at it. |
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McCarty
join:2006-03-24
Brooklyn, NY
1 edit | reply to Gorgo
»Optimum Online FAQ »What should my modem levels be?
I can tell you that installing an amplifier raises the upstream and noise ratio signals. The tech installed an amp; this sometimes causes frequent modem disconnections in the day. However my cable tv is flawless no pixelation
receive Power Level
0.3 dBmV
Signal to Noise Ratio
36.8 dB
transmit Power Level
53.2 dBmV |
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cablewizzard
join:2009-06-14
Hicksville, NY
| reply to anonname
said by anonname :
A 54 is within range and would not cause an issue. However there is another problem and you need to have someone come look at it.
The OP stated one of his DSTBs is above 55dBmV transmit as well, so it's likely the entire household has a problem - and yes, the stark imbalance with the receive level is why this must be looked at and corrected into a more favorable condition.
While 54dBmV on transmit for a DOC2.0/ATDMA upstream may be within range - it's THE MAX with no further breathing room to compensate for any further deterioration due to day2day temperature- or long-term changes to the plant (balancing a node may work AGAINST you at times!)
The receive level at the CMTS may already be unacceptably low as well - you can't tell that from the subscriber side - and the modem may or may NOT permit itself to go beyond 54dBmV transmit power, and thus finally go "over the edge", and get noticed.
Whether individual customer service reps have been properly educated to check the signal receive level at the CMTS is a good question! A @54dBmV "pass check" does not guarantee stable operation, indeed, it's the kind of condition that needs to be red-flagged and addressed BEFORE service issues occur: if the brakes squeak, it's time to take the car to the shop, you know! |
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