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JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

Premium Member

Getting Charter to fix low signal levels

What is the best way to go about getting Charter to fix low signal levels? They aren't causing any real issues other than if they get too much lower the cable modem loses sync completely (only happened once so far, yesterday). Speeds are fine, I have no problem saturating either direction for hours on end. Given I can't get to the logs on the Cisco modem I can't tell you anything about any correctable or uncorrectable errors.

I'm currently seeing averages around -18 with it going as low as -20. SNR and upstream power are acceptable, borderline depending on which modulation but also could be better.

My incoming circuit looks as follows:
Ground Block on pole -> surge protector on UPS (has about a 2dB loss) -> 8-port powered splitter -> devices

I have the modem on one of the powered ports (the power brick is on the UPS as well so I'm not worried about losing service in an outage). If I put the modem on the VoIP port I will have an additional 3.5 dB loss (it seems there is an internal 3.5 dB leg for the main part of the splitter and another cascaded 3.5 dB leg for the VoIP port as I measure a total of 7 dB loss).

Last week when I rewired the inbound circuit through the UPS I took measurements at different points. Straight off the ground block, through the UPS only and on a powered port of the splitter.

Stright off the ground block had: (-8.8, 38.2), (-7.5, 38.6), (-6.5, 38.7), (-5.7, 39.3)
Through the UPS only had: (-10.8, 37.1), (-9.5, 37.5), (-8.5, 37.8), (-7.8, 38.4)
Finally, on the powered splitter had: (-14.2, 34.5), (-12.8, 35.2), (-11.7, 35.6), (-11.2, 35.9)

Judging by those numbers and what I see now, it looks like over the last week, they've worsened quite a bit. They've always been quite low like this but this is the first time I've had them get low enough to kick me offline.

yourcableguy
@68.114.34.x

yourcableguy

Anon

If your loss is higher after going through the powered splitter, something's wrong with your splitter. Your received power should increase after going through the powered splitter since it has an inline amplifier.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

Premium Member

I thought about that. At the very least I thought it should maintain whatever signal level it received if it didn't amplify it as well. We did have to replace the power supply for the splitter, the original one got damaged (physically damaged, I think someone kicked it....). We didn't replace the splitter as it came online just fine after replacing the power supply but I wonder if it had some hidden damage?

The bad part is they took all the techs out of the local office and now route them out of Lagrange or Auburn/Opelika which has the effect of taking all the supplies out of the local office too. I had to wait on a tech visit just to replace the power supply on the splitter when before I could have picked up a new one at the local office (they did look because sometimes people will bring that with the boxes if they discontinue service but alas no luck).
JoelC707

JoelC707

Premium Member

Just decided to refresh the modem stats page and was surprised to see the levels have improved. It may be because it's late at night and things have "cooled off" so to speak. I'll check again in about 12 hours or so when it's hotter out and see if that is really the case. I think they're still a bit low but at least now I'm not borderline being knocked offline.
Ctech
join:2013-07-27

Ctech

Member

The eight way powered split should have no loss so yours is probably going, -8 at the ground block is terrible signal as well. how are you measuring the signal? with the modem? if you are using the modem it could possibly be going bad as well and not showing accurate signals. do you have tv service? because at those levels the tv service would show issues as well. regardless, if those are your true levels, its time to schedule a tech visit.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

Premium Member

Yeah I'm using the modem to measure. I used to have a basic hi-channel/low-channel signal measurement device my dad bought when we worked as Comcast subs but sadly in the course of a couple of moves that and all the rest of the coax (and many of the networking) tools have disappeared.

The measurement at the ground block was done inside the house so it did still have about 50-75 feet of RG6 but that wouldn't induce a large amount of loss. TV service does have some tiling/macro-blocking occasionally but overall is fine. It's mostly on the HD channels or one of the sub-channels (such as MeTV that is a WRBL 3.2 channel) that I have issues with, if I have any issues at all.
Jazzemt
join:2009-02-12
USA

Jazzemt to JoelC707

Member

to JoelC707
Do not use the surge supressor on the ups. They are very dirty and will cause signal quality and sometimes level issues. They are stupid simple and not really designed for use in a broadband system. The amplifier (powered splitter) has an issue. If you want a truck rolled tell them the issues with video you are having and that you keep getting kicked offline. If you need to convince them that you have an issue, unplug your modem before you call them and tell them you are currently offline. They will roll a truck.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

Premium Member

I suspected the UPS might have something to do with the issues. I was frankly surprised it worked at all as I expected it to block the return path. I had storm/surge damage not long after I moved in here (fresh install) and I believe it originated on the coax line as the primary deaths were the cable modem, a couple of tv boxes and three TVs. That's why I went to the UPS option since the ground block didn't seem to be doing it's job. It's worth taking the UPS out of the loop though as if nothing else it gives me 2dB worth of buffer before I have major issues.
JoelC707

JoelC707

Premium Member

Just wanted to give an update to the thread. Thanks to a certain user (not sure if he wants me to name him or not) here I was put in touch with the supervisor in the area and he confirmed I had a problem as their logs were showing a 5-6 dB swing (or worse) through the course of the day and that alone indicated a problem in addition to it averaging -15 for so long.

Charter tech came by last Saturday and took various measurements at the modem, splitter, ground block and finally the pole. He said signal was very low at the tap port and indicated a problem with the tap or somewhere on the line and he would need to kick it over to line maintenance. He did say that my drop should have been RG11 to start with and not RG6 so he replaced that and the ground block (gained me about 2-3 dB worth of signal).

This morning the line maintenance tech came out. Only reason I knew he was here is because he called to find out where the hell we were (GPS will send you a mile or so from here lol). He stopped at the amp one pole back (we have two cable plants here so I didn't know which was which and didn't know I was one pole away from an amp which means I should have had much hotter signal than I do) and opened it up. He drove off a few minutes later looking at the span as he left. He left the amp casing open so I'm guessing he is hunting the source of the issue.

All in all, I'd say I'm well on the way to recovery at this point.
JoelC707

JoelC707

Premium Member

Much better! He knocked on the door and asked me what problems I was having and to check them now. He said he had to go all the way back to the node as it was too low and adjust all the way down the line. I'm now seeing -2 to -3 dB with much tighter tolerances between channels, SNR and upstream power have improved considerably too.

He also said this was due to their digital changeover, he's had to go around readjusting things all over the place because of that. I can actually believe that because while my signals have always been low in my opinion, they didn't really start getting dangerously low like this until after the digital change on April 15th and it really started showing up when they activated 8 channel bonding in the area.