Contributor
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46 Messages
Strange power levels: cause?
If my understanding is right, the power levels and other numbers here are way out of whack. What could be the cause of this?
(I have cabling installed by Comcast entering the house, entering a MoCA PoE filter, entering a Comcast supplied and installed two-way splitter, attached to house cable, attached to two-way Comcast supplied and installed two-way splitter, attached to Comcast cabling attached to a Comcast gateway. Total db loss due to splitters is 3.5 X 2 = 7. MoCA is active.)
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Downstream
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Channel Bonding Value | ||||||||||||||||||||||||
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lock Status |
Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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Locked
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| Frequency |
513 MHz
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459 MHz
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465 MHz
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471 MHz
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477 MHz
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483 MHz
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489 MHz
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495 MHz
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507 MHz
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519 MHz
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525 MHz
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531 MHz
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543 MHz
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549 MHz
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555 MHz
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561 MHz
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567 MHz
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573 MHz
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579 MHz
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585 MHz
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591 MHz
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597 MHz
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603 MHz
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609 MHz
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| SNR |
32.237 dB
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30.885 dB
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29.759 dB
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28.062 dB
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27.607 dB
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30.002 dB
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31.915 dB
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33.377 dB
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32.963 dB
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31.994 dB
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32.237 dB
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33.487 dB
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35.084 dB
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35.595 dB
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34.926 dB
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33.957 dB
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34.346 dB
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33.957 dB
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34.484 dB
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35.084 dB
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35.595 dB
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35.595 dB
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35.084 dB
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34.926 dB
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| Power Level |
-18.700 dBmV
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-20.800 dBmV
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-22.100 dBmV
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-24.100 dBmV
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-24.600 dBmV
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-21.600 dBmV
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-19.100 dBmV
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-17.400 dBmV
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-17.300 dBmV
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-19.100 dBmV
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-18.500 dBmV
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-16.700 dBmV
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-13.500 dBmV
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-13.200 dBmV
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-14.400 dBmV
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-15.300 dBmV
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-15.100 dBmV
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-15.500 dBmV
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-14.300 dBmV
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-12.700 dBmV
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-11.700 dBmV
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-12.000 dBmV
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-12.600 dBmV
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-13.100 dBmV
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| Modulation |
256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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256 QAM
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Accepted Solution
EG
Expert
•
111.4K Messages
5 years ago
You need a tech out to investigate as was stated earlier. Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. Good luck with it !
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lairdjn
Contributor
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46 Messages
5 years ago
I'm using https://pickmymodem.com/signal-levels-docsis-3-03-1-cable-modem/ to discern what is "out of whack" and what is not.
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EG
Expert
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111.4K Messages
5 years ago
In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test
If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.
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lairdjn
Contributor
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46 Messages
5 years ago
Thanks for your reply. The splitters I documented are the only ones, and they were supplied by Comcast. Sadly, I can't drop down to one splitter.
Do you have any wisdom to impart on the power levels in particular? To my naïve eyes it looks like they're too hot, not too low.
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EG
Expert
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111.4K Messages
5 years ago
The downstream power is way too low ! So are the SNR's. You didn't post the upstream power levels.
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lairdjn
Contributor
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46 Messages
5 years ago
Let me ask you this, if I may: is low power due to the splitters (I've certainly been in places where there have been lots more splitters involved!), or more likely due to cable run? (From the outside of the house, the cable cuts across a garage bay and into a combination furnace/telecom room. Not very long, but what do I know?)
There are no unterminated jacks or anything like that, so no place (under my control) for noise to "leak" in to the circuit.
(I hesitate to get a tech out because usually they're under time pressure so they just swap out the cables the previous tech has installed and leave. I understand that bang for the buck wise this probably is a quick way to get many problems fixed, but in this case I strongly believe something else is up.)
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lairdjn
Contributor
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46 Messages
5 years ago
Ah! OK, I'm glad I asked, and thanks again for your reply.
Here's the rest of what I didn't post originally (sorry about that):
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EG
Expert
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111.4K Messages
5 years ago
It could be. The more splitters that are cascaded, the more the loss. It especially is a problem if the incoming signal from the street / pole is already too weak.
And the upstream power it WAY out of spec too ! So much so that you've lost the bonding of the multiple channels....
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