I've noticed that our modem signal changes dramatically when we are in the heat of the day here in Texas. It's the same pattern each day.
Right now it's evening, the best channel has -4.0 dBmV/39.3 dB power/SNR and the worst channel has a -12.0 dBmV/33.1 dB power/SNR. In the afternoon when the temperature outside is up near 100F then the worst channel is at <15 dbmV and <30 SNR - and we see a lot of errors on the channels with lowest signal. Today we also had many more issues with internet and some TV channels around 5pm, but things became watchable again as it got cooler in the evening.
The house is a year old with RG6 cabling. The TWC installation was last week with a single 3-way spliter feeding our modem, the telephone adapter and the cable box. The installers removed the splitter in our attic leading to other room, so the feed into the house goes directly to the single 3-way spliiter.
Just wondering if it's usual to see poor signal when it's getting very hot - and also such a big difference in power between the best and worst channel on the modem?
I tried to raise the issue with a TWC chat agent - but they were only interested in if things were working now, which they are - as it's now the evening and cooler.
The current modem stats, from the cooler evening, are below.
Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
|1||QAM256||783000000 Hz||-4.0 dBmV||39.3 dB||502131||649802|
|2||QAM256||771000000 Hz||-4.1 dBmV||39.0 dB||408489||620542|
|3||QAM256||777000000 Hz||-4.0 dBmV||39.2 dB||415301||626134|
|4||QAM256||789000000 Hz||-4.3 dBmV||39.1 dB||419205||614580|
|5||QAM256||795000000 Hz||-4.7 dBmV||38.9 dB||414549||600527|
|6||QAM256||801000000 Hz||-5.8 dBmV||38.4 dB||419958||611905|
|7||QAM256||807000000 Hz||-7.4 dBmV||37.6 dB||415227||614369|
|8||QAM256||813000000 Hz||-8.9 dBmV||36.8 dB||342736||476458|
|9||QAM256||819000000 Hz||-9.8 dBmV||36.1 dB||378886||551866|
|10||QAM256||825000000 Hz||-9.8 dBmV||36.0 dB||420235||640514|
|11||QAM256||831000000 Hz||-8.6 dBmV||36.7 dB||423710||626246|
|12||QAM256||837000000 Hz||-7.8 dBmV||37.1 dB||427504||632512|
|13||QAM256||843000000 Hz||-8.8 dBmV||35.9 dB||439395||633777|
|14||QAM256||849000000 Hz||-9.2 dBmV||35.9 dB||445906||608054|
|15||QAM256||855000000 Hz||-10.4 dBmV||34.9 dB||482633||653871|
|16||QAM256||861000000 Hz||-12.0 dBmV||33.1 dB||51336581||1145120|
Total Correctables Total Uncorrectables
Upstream Bonded Channels Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
|1||ATDMA||5120 Ksym/sec||30600000 Hz||51.0 dBmV|
|2||TDMA||2560 Ksym/sec||19400000 Hz||49.0 dBmV|
|3||ATDMA||5120 Ksym/sec||24200000 Hz||50.5 dBmV|
|4||ATDMA||2560 Ksym/sec||37000000 Hz||52.2 dBmV|
Yes, the signal will drop with temperature, this is normal, and if your line, and equipment are in order,
you would never notice the problem since it would stay in range, your signals are high on the upstream
and low on the downstream.walk or look at your cable make sure everything is tight/firm, no wrench,
tech will need to come back as you have a cut in your line, bad connection.
Your entire connection is out of spec, There are too many or open port splitters and probably trashed coax outdoors from weather or rodents/ raptors or worst yet, rg 59.
Your modem & dvr's won't work right
modem must be on no or the first 2 way splitter, check your wiring!
those levels are terrible... Move the modem to where a dvr is and see what the levels are.
I don't understand how lines can be new and already spliced because there were too many splitters...
Is this overhead line? Does it run thru trees? Can you get a photo of the pole connections, looking for any additional splitters for neighbors?
If you have a neighbor on the same tap, see what there levels are.
Look in the dvr's diag page and see if those are 3.5 db worst to verify the ports are as you stated.
Hold in the select for 10 seconds and then hit the up arrow...
TWC needs to send a tech out
They are now sending a tech out tomorrow after directed an agent at this forum thread. Thanks - seems like a good way to avoid runaround.
I'd already tried moving things on the splitter, and the modem signal does how about 3db lower if moved to the DVR port on the spliiter - so the 1 port at -3.5dB, 2 ports at -7dB seems accurate.
We previously had Verzion FiOS for a year. That had a single 2-way 5-1000MHz splitter in the attic to feed 2 rooms only - single DVR and FiOS MoCA router in separate rooms. The cabling was put in by builder and verizon connected and put in that single splitter. At TWC install they replaced the 2-way in the attic with a straight through coupling between feed coming from drop and outlet in one room only - where there's our 3-way splitter and all connected equipment. So we have
pole----->TWC box on house----->attic-straight-coupler----->outlet----->3-way splitter (modem/DVR/telephone adapter)
The line is overhead from pole (which is at end of our driveway) to house and completely clear of trees. Not at home for a photo now - but from looking at pole previously our drop seems to come out of a 6-port tap which is right next to what I believe is a amplifier (grey box with fins attached to larger cables running down street). Nobody else is connected and no neighbors to check with. Everyone is FiOS - as we were before Frontier purchase gave loads of issues and we decided to switch to get more for less.
All that's in the TWC box is a grounding block, not a splitter, correct?
normal tapoffs are 2-4-8's
Sounds like there's an issue up there and it's either blown or the wrong value
Look at your DVR levels and see if they're 3 dB worst
If so, it will be unreliable as well.
Too much to hope for.... things came back from the total outage with just the same bad signal. TV reception is bad and modem low power etc.
Looks like our drop comes from an 8-way tap at the pole. The TWC box on house only has one cable in and one out - so presumable just a ground block, no splitter.
Fingers crossed it gets fixed tomorrow.