So, agentx5, what are you saying? In my area (Greensboro NC) we are apparently up to 24 channels now. Is a Docsis 3.0 16-channel modem worth buying or is it/will it be problematic/obsolete now or when it goes up to a 32-channel system? Also, Docsis 3.1 will be implemented eventually..... what effect will that have on all this?
Those of us who buy our own modem want to get something that won't have to be replaced in a year. My SB6141 continues to be highly problematic in this system despite still being on the new "approved modem" list, for speeds up to 100 down.
Your 6141 is not the issue, it's TWC infrastructure... Spectrum is foolishly replacing both 8 and 16 channel modems with 8 channel ones, so I seriously doubt there's any imminent change to docsis 3.1 which will require huge outside plant replacement which they simply can't afford to do.
It's only advantage is for IPtv which they won't do either, as they want to rent out cable boxes.
and keep the tv/ internet seperate.
You probably should update your connectivity post.. what's it doing now?
Yeah, I'll update the old thread of mine, but while it IS an infrastructure issue, only the SB6141 is exhibiting the symptoms and having issues.... so it IS a modem problem in that respect. Now that they are up to 24 DS channels here, the 8 channel modem is getting channels in a range greater than its design range. The 6141 has two radios that together give it an operating range of 96 MHz. With a 24 channel system, as some DS channels eventually switch for higher frequency channels (due to intermittent noise, or whatever reason), the modem ends up with 8 channels that range from 507 MHz to like 639 or 645 MHz. The SB6141 is then outside its operating range by quite a bit.
My question here is what 16 channel modem-only modem on the approved list is recommended. Karl has been touting the Motorola MB7420. Is a 16 channel modem going to continue to work with a 24 channel system, or 32 channel system if they decide to upgrade it again? Is the MB7420 a better unit with this infrastructure, than one of the Arris-branded models?
You are being forced to buy a modem to solve TWC/Spectrums coaxial ingress issues which is wrong.
As for the 6141, I've never seen docs that says it has 2 seperate 4 channel tuners in it... there are some other ones, including the 8 ch one Spectrum is handing out that claim to. But that is somewhat used for IPTV which Spectrum doesn't send via customer internet modems, they may be via the dvr/cable boxes internal modems however.
If Spectrum started selling lets say "netflix" or some sports package as a smart t only service, they might stick those channels in their own seperate 4 channels.
But as for exceeding rated "capture bandwidth", The issue is way worst if the ingress is severe on skipped channels with ALL modems, it screws up the DSP and levelling for the channels it is trying to actually use so there is horrible settling time, and speed is dropped drasticly. In all modems, you want channels all in a row without any skips other than the home (1st) channel can be within the other7 or 15 channels span
The MB7420 has a full range [108 to 1002 MHz] receiver, no problem with channel spacing, IF all intervening unused channels are free of IM products and/or ingress.
Ms. Raye, the SB6141 manual's spec pages say :
Downstream Channel Capture: Dual 96 MHz Tuners
DOCSIS ≤ 48 MHz/2
EuroDOCSIS ≤ 64 MHz/2
I agree, I'm being backed into the corner of having to buy a 16 channel modem to solve Spectrum's infrastructure issues. I've been dealing with it and documenting it for them, and working with the lineman Billy, for nearly a year now. it was fixed for a little over a month, then Spectrum changed everything and it all fell down, as bad as a year ago.
Bottom line, i want to use my Internet service, not work for free for Spectrum troubleshooting it. My only remaining option is to contact the state attorney general's office..... and in this state, the government is more concerned about appeasing businesses than protecting consumers, so that might not get anywhere.
When I get a chance, I'll update my original ongoing thread.
48+48=96 96 mHz is the modems maximum acceptance bandwidth.
20 ch's = 126 mHz,
30 ch's = 186 mHz
And every one misses the glaring defect in the scan.. If there is severe ingress on a skipped channel, and if it's at a higher level than the adjacent channels, the Qam detector/ decoder will get confused. Corrected and uncorrecteds go way up.
Ms. Raye wrote:
"In all modems, you want channels all in a row without any skips other than the home (1st) channel can be within the other 7 or 15 channels span'
What I've seen in practice here makes me wonder if that's entirely correct. DOCSIS 3.0 allows for skipped channels, it's built into the specification. What I see with the 8-channel SB6141 is, IF the "home" channel (starting channel, what the 6141 call "favorite frequency") is at the bottom of the range, it will get consecutive channels and in numeric order, when first booted. So, if the lowest channel in the Spectrum/TWC range is 507 MHz, and 507 is set as the home channel in the modem config file, upon starting the modem it will get 507 and then consecutively higher channels in order, for the remaining 7...... 513, 519, 525, etc.
However, if the home frequency is, say 525 MHz, the channels may appear consecutively but out of "order"..... the signal page may show 525, then 513, then 519, etc.... consecutive, but not in order.
But (as happened here for a while), if Spectrum changes the config file and and puts the home frequency higher in the band, the modem gets to groups of channels that are not consecutive or near each other, upon start or reboot. For example, for a while in January, they changed my modem's home channel to 645 MHz.... the highest frequency of the available channels. Here you could see how the two radios in the 6141 worked: the signal page upon reboot would show from left to right: 645, 633, 639, 627 (four consecutive, but out of numeric order), 507, 513, 519, 525 (four consecutive, reverse order).
Those two groups of four were far apart from each other, as far as they could be.... the four highest freqs and the four lowest freqs. Each group was only consecutive within its group of four. That led me to believe the two radios were grabbing one group each, and NOT consecutive with each other, but independently.
Here's an example of that, from January, when the home freq was too high:
Sorry for discussing this in someone else's thread, it just came up in the discussion. I can move this portion of the conversation to my old thread, later.
May I jump in here? Thanks, agentx5, for your comments about the SB5101. That is my current modem, and it's clear if I want to migrate from TWC to Spectrum I will need to buy a new one. So you inadvertantly answered the question I had when I signed on.
So . . . do you have an opinion about ASUS' RT-N66U "Dark Knight" router? I do believe it is compliant with Spectrum's set-up but don't see it listed as recommended (the Spectrum list has just three routers on it).
I do prefer to buy my own equipment.