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neufuse

join:2006-12-06
James Creek, PA
Reviews:
·Comcast
reply to JeepMatt

Re: [Connection] Bad node / outside line again...

You know, I was thinking something seemed odd about my HSI channel frequencies... they where never in the 600's before but now they are. Mine start at 603MHz and go up to 621MHz (we only have 4 channel bonding right now) I was thinking these use to be in the mid 700's

neufuse

join:2006-12-06
James Creek, PA
reply to rody_44
I think the new line is pigtailed to a more flexible cable... bending QR320 in a small tap pedestaled would never work... but the old line that went into a larger box where the LE was, they ran the old line right into the port on the amp


gar187er
I do this for a living

join:2006-06-24
Dover, DE
kudos:4
reply to JeepMatt
i dont know about other system moves, but for the kent county area our HSI qams are at 579-650 ish and always have been. we added VOD up high as directed by region.

I hate having HSI up high due to attenuation reasons, but if your HSI was up in the 750s, i would assume this could be one reason for the move.
--
I'm better than you!


JeepMatt
C'mon the U
Premium
join:2001-12-28
Wilmington, DE
kudos:3
Reviews:
·Verizon FiOS
·Comcast
Yeah, ours used to go up to at least 735MHz....

Then I noticed over the summer the change. For the few areas that I've noticed 16 QAM's getting launched for the DS - they use the entire 600 range. Right now New Castle is from 651-693 (top half).
--
"ONE team - ONE city - ONE dream!!"


Streetlight

join:2005-11-07
Colorado Springs, CO

2 edits
reply to neufuse
I have the same kind of problem only it's with lower frequencies - and happened in May and now in November. These are HD channels on frequencies between 129 MHz and 147 MHz having the problem with the three channels sharing 129 MHz having the worst degradation and are unwatchable and sometimes "unavailable" to view and the one I see at 147 MHz slightly pixelated. The problem shows up after sunset and continues 'til the sun is up awhile in the AM. S:N ratios drop from 37 dB to 27 dB. Around sunset the pixelation comes and goes over an hour or so and then pixelation continues overnight 'til after morning sunrise. I can't find any other channels, SD or HD, that have this problem. I can't find the power levels on the HD DVR, so I'm assuming, rightly or wrongly, that the S:N ratio is changing because of a change in signal, not noise. It's not the HD DVR because the same thing happens to the one common, 129 MHz channel viewable on both the HD DVR and our HD DTA.

One other very interesting thing is what happens to the cable modem downstream power level. It's completely synched to what's happening with the TV system: it drops ~12 dBmV from about +11 dBmV to -1 dBmV and bounces up and down in complete synchronization with the appearance and disappearance of the drop in S:N ratio shown on the HD DVR. That is, when the modem shows + 12 dBmV signal the TV is free of pixelation and when it's -1 dBmV there is pixelation. Upstream levels do not change at all during all this. The modem downstream S:N ratios do not change during problem times, only power levels. The frequencies are vastly different, with Internet at ~585 -621 MHz downstream and ~ 30 MHz plus/minus 6 MHz upstream frequencies. Internet performance throughout all this is very stable. In the past with the high downstream power levels I've added a two-way splitter at the modem to reduce the downstream power level to ~7 dBmV, raising upstream to ~46 dBmv.

I have had techs out to look at this over the years with no joy. It's also interesting that just about everyone else in the neighborhood have abandoned Comcast because of these problems going to Directv and Century Link for Internet. One house has actually switched both TV and Internet to Century Link's Prism TV. Gasp! This guy saw me talking to a CC tech one day and came over to ask about why his TV and Internet were so bad. The tech accessed his system on his cell phone and agreed there was a problem, called in to tell someone about the problem, but nothing ever cleared it up. Within a month, CC was gone from his house.
--
There is nothing more deceptive than an obvious fact.

Sherlock Holmes in
The Boscombe Valley Mystery
A. C. Doyle
Strand Magazine, October 1891


Streetlight

join:2005-11-07
Colorado Springs, CO
Problems found and solved.

I finally called Comcast this AM, and a tech - Jamie - arrived at 5:00 PM today. I told him what I posted in my original post in this thread and he understood exactly what I told him. He said, well, the DVRs S:N ratio could have dropped because the signal stayed the same and the noise went up, but I suggested that on the modem, the downstream S:N ratio stayed the same even though the power level went down, so I guessed the signal dropped with little change in noise levels. When he put his meter on the pedestal outlet he found the signals were indeed low and proceeded to move down the street to check the ped feeding my pedestal and jigling that ped took out the whole neighborhood! A fuse was blown in the Alpha box several blocks away. He found that the large cable feeding the 2nd ped had been installed in a way that the coupler cut through the shielding shorting out the center conductor. Wiggling it caused the short. By this time a 2nd line tech came to assist. They also found a 2nd problem in the 2nd ped involving a small blue box - can't remember what it was called. The problem I had involved two points of failure which is not at all what one would expect.

When I told him that generally my modem's downstream signal level was around 11 to 12 dBmV, he said it might even be higher after the fix, but he was able to adjust the output of the ped so it was about 11 dBmV. Then I asked if he had any low pass attenuators so the low frequency upstream signal would remain low at ~40-42 dBmv but reduce downstream signal level to a more acceptable level. Sure enough, he gave me three of them - a 6 dB, a 9 dB and a 12 dB low pass attenuators. Perfect for my situation with the flexibility I may need. I checked them out and they work just as promised. Others have commented in these forums about the use in England of Forward Path Attenuators for just this purpose and wondered whether they were available from Comcast. At least this Colorado Springs tech had them in a variety of attenuation values. The label notes: Commscope SVCS, but no part number. They're called Inline Cable Simulator on Commscope's web site:

»www.commscope.com/catalog/broadb···px?id=26

The site suggests they sell these in 800 unit packages. If you're having the problem of high downstream signal with appropriate upstream signal, you may have to flag down a Comcast truck to get these. I can't find them on Amazon, but someone in these forums may know where they can be had in single units.

I have to compliment Comcast's fast and competent service in this case, and particularly the techs that came to my - and my neighborhood's - rescue. What was neat about Jamie is that he listened to what I had to say and complimented me because my observations saved him considerable time in locating the problem.
--
There is nothing more deceptive than an obvious fact.

Sherlock Holmes in
The Boscombe Valley Mystery
A. C. Doyle
Strand Magazine, October 1891