61dBmV upsteam power and connection problems.
Bookmark this page:
 Yahoo!
 Google
 Windows Live
 del.icio.us
 digg
 Netscape
|
|
|||||||||||||
|
Posted by Chris R. Speaker on May 19, 2006, 12:05 pm
Please log in for more thread options I've been having trouble with my cable connection (Comcast) for some time now. I've tried changing splitters to no avail. My downstream specs: Lock Status Locked Modulation 256QAM Channel ID 36 Symbol Rate 536.0537 Ksym/sec Downstream Power 0.0 dBmV SNR 33.3 dB My Upstream specs: Lock Status Locked Modulation 16QAM Channel ID 1 Symbol Rate 2560 Ksym/sec Upstream Power 61.0 dBmV I have done some homework and I know the 61.0 dBmV is way out of spec but I don't really know that I can do about it. Any help would be greatly appreciated! Please remove the nospam and replace it with @ for email. chris_s1nospam.comcast.net | |||||||||||||
|
Posted by Warren on May 19, 2006, 1:32 pm
Please log in for more thread options Chris R. Speaker wrote: Essentially your modem is screaming at the top of it's voice to be heard. Things that you can check in your house are: + Make sure the cable is RG6 not the older, thinner RG59 + Make sure the cable is not damaged + The ideal set-up is a separate run from the "pole" to the house just for your cablemodem, but if that's not what you have, make sure there is only one splitter on the path to the cablemodem. If that splitter is a 3-way, make sure it's on the leg of the splitter that has the least signal drop. + If there is a splitter, it shouldn't be a cheap TV splitter. It should have a wide frequency range. + There should be no amplifiers on the path from the cablemodem out of the house. + If there is a filter located near the splitter, it should be on the leg going to the runs to the TV, not on the run to the cablemodem, or on the run into the house + The run to the cablemodem should be a piece of continuous cable, not a couple of pieces spliced together + All connections should be corrosion free even if they're outside. It's possible that everything in your house is perfect, and the problem is outside your house. In that case, it's out of your hands, and you'll need to get a technician sent out to your house. (Note that you don't have to crawl around your attic or crawlspace to check all those other things, either. The technician will be able to take care of any of those issues if they're causing the problem, too. You also shouldn't have to buy any new cable, connectors, splitters, filters, or whatever. Those things will be provided by the cable company if you need them.) -- Warren H. ========== Disclaimer: My views reflect those of myself, and not my employer, my friends, nor (as she often tells me) my wife. Any resemblance to the views of anybody living or dead is coincidental. No animals were hurt in the writing of this response -- unless you count my dog who desperately wants to go outside now. Power Lawncare Tools for Spring Clean-up: http://www.holzemville.com/mall/blackanddecker/ | |||||||||||||
|
Posted by none on May 19, 2006, 8:14 pm
Please log in for more thread options
Check with a couple of neighbors and find out the Upstream power levels on their modems, if they have more than 50 dBmV, then the cable company have may have to adjust the reverse amplifier in your neighborhood. Bottomline is - if nothing has changed in your home since you last had good connection, it may not be something you can fix on your own. | |||||||||||||
|
Posted by Eric on May 20, 2006, 10:47 am
Please log in for more thread options
"Check with a couple of neighbors and find out the Upstream power levels on their modems" Or, call Comcast and say your connection is not working. Unplug your modem before you call, so when they run a test, it will show offline. Fib if they ask you to powercycle the modem and say you did. Don't bother your neighbors unless Comcast is unwilling to fix the problem. | |||||||||||||
|
Posted by Eric on May 20, 2006, 11:10 am
Please log in for more thread options
Warren Wrote: "+ Make sure the cable is RG6 not the older, thinner RG59 " Actually, RG-59 and RG-6 are very similar when it comes to upstream losses. RG-6 has much less loss/100ft at high frequencies (above 400MHz), but there's only about 1/2dB difference at subband frequencies: http://tinyurl.com/h7pg5 - Commscope RG-6 sheet (pdf) http://tinyurl.com/kb7s4 - Commscope RG-59 sheet (pdf) Otherwise, great advice. The problem with RG-59 is that it is more likely to be damaged or poor quality, because it has been exposed to weather and other hazards over the years. "All connections should be corrosion free even if they're outside. " That is the 2nd most common cause of high modem transmit levels. Old connectors that were not installed properly, no weather seal, waterlogged centerconductors. The most common cause I see is junk splitters, FYI. You may want to take a look at your tap (where your house connects to the pole), if you are in an area served with aerial cable. If it is labeled with a 26 or 23, it means the modem will have to transmit higher than if it is a 14 or 11. If it is a 26, you really need to make sure the modem is split ahead of everything else in the house. This is how all installations should be in an ideal world, but we all know how that works. The engineers who design the systems don't live in our world, so they continue to use these high value taps. :) Anyway, you need to have someone come out and take a look at things. Any tech worth his pay should be able to see a problem right away. | |||||||||||||
| Similar Threads | Posted |
| 61dBmV upsteam power and connection problems. | May 19, 2006, 12:05 pm |
| Upstream Power hits 51.9dbmv and connection dies... | November 16, 2004, 1:26 am |
| Connection problems | June 10, 2005, 2:43 pm |
| OK, my connection problems baffle me | August 8, 2004, 1:00 pm |
| Connection Problems Cat5 vs. Cat6 | September 29, 2007, 6:19 pm |
| Problems with Surfboard 5100 and linksys router connection | December 20, 2005, 3:12 am |
| BEFSR41 led behaviour on power-up | August 30, 2004, 4:02 pm |
| downstream power level? | December 21, 2004, 8:01 pm |
| Power Levels on Motorla 5100? | July 11, 2004, 3:09 pm |
| distance between power and communication cablel | February 10, 2005, 4:13 pm |
| Cable Modem Sleep/Standby Power Requirements | May 24, 2005, 5:05 pm |
| Great Wake On Lan Test that gives you 2 minutes to power down the computer | December 16, 2005, 8:11 am |
| ntl connection | April 5, 2005, 9:38 am |
| Internet Connection | July 15, 2004, 2:58 pm |
| Internet Connection | August 9, 2004, 12:12 pm |
> time now. I've tried changing splitters to no avail.
>
> My downstream specs:
> Lock Status Locked
> Modulation 256QAM
> Channel ID 36
> Symbol Rate 536.0537 Ksym/sec
> Downstream Power 0.0 dBmV
> SNR 33.3 dB
>
>
> My Upstream specs:
> Lock Status Locked
> Modulation 16QAM
> Channel ID 1
> Symbol Rate 2560 Ksym/sec
> Upstream Power 61.0 dBmV
>
>
> I have done some homework and I know the 61.0 dBmV is way out of spec
> but I don't really know that I can do about it. Any help would be
> greatly appreciated!
>