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sandman_1

join:2011-04-23
11111
reply to SanAntonioTx

Re: Timewarner doesn't care about me UPDATE FIXED IT

glad you got them to fix. I had them run a new line and it fixed my issues.

on a different note, maybe theyvcan fix your Sprint LTE 50mbps connection. wait I guess they did...


news

@videotron.ca
reply to trparky
said by trparky:

Then if that's the case, TWC will have to do some work on their plant in my area to have upstream bonding work.

Why I say that is because I can see my cable node, I know where it is. I've traced the cable from the node to the tap that I'm connected to and it's a very short distance. Probably less than 1000 feet. Still I have an upstream power value of 51.2 dBmV.

It's normal to have higher upstream power near the node or distribution amplifier, cause the first taps of a cable line are high value taps. It's the way a cable plant is designed. Node or distribution amplifier = high value taps = high upstream (high value tap) and = high donwstream power (less cable loss cause you are near the amplifier). End of line = low value tap = low upstream power = low downstream power (more cable loss).

51 dBmV upstream power near a node or distribution amplifier is ok, but if you have only 40, that's means there's something wrong (return level too high at the node or amplifier). 51 dBmV on a end of line isn't ok, there's something wrong...

etaadmin

join:2002-01-17
Dallas, TX
kudos:1

2 edits
said by news :

It's normal to have higher upstream power near the node or distribution amplifier, cause the first taps of a cable line are high value taps. It's the way a cable plant is designed. Node or distribution amplifier = high value taps = high upstream (high value tap) and = high donwstream power (less cable loss cause you are near the amplifier). End of line = low value tap = low upstream power = low downstream power (more cable loss).

51 dBmV upstream power near a node or distribution amplifier is ok, but if you have only 40, that's means there's something wrong (return level too high at the node or amplifier). 51 dBmV on a end of line isn't ok, there's something wrong...

I never thought about it that way but it makes perfect sense... you must work for the industry

The signal level immediately from the node is always high so the node will be a able to feed everyone to the end of the trunk. So to achieve the 'target' level for the first customer in the line (people closer to the node) a high level attenuation tap should be used but this attenuation is not unidirectional (upstream and downstream) it affects both signals the same way so the modem to compensate for the added attenuation it has to increase its power output (upstream).

This is not a sign of a problem just the specific characteristics of being first in line, conversely the last customer in the trunk will have a
greatly diminished signal to play with so a very low attenuation tap will be required but since he is already at the end of the trunk the modem will have to use more power to reach the node.

Got it right?

EDIT: What would happen if another amplifier is needed/added to feed another trunk? Will the last customer of the first trunk cause problems on the second amplifier?


swintec
Premium,VIP
join:2003-12-19
Alfred, ME
kudos:5
I am the very last tap on this branch and my upstream power level is 32 dBmV. No problems here.

etaadmin

join:2002-01-17
Dallas, TX
kudos:1
said by swintec:

I am the very last tap on this branch and my upstream power level is 32 dBmV. No problems here.

Here too last home at the end of the street... sounds like one of those horror movies

My output power is 40dBmV, never had a problem.


G0d

@rr.com
reply to SanAntonioTx
So the real problem is your home network. Your problem is most likely caused from ingress on your other outlets being combined. By them putting your modem on a separate drop your house wiring network is not tied to the modem anymore and cannot effect it in anyway. Now if it was extremely bad it can effect everyone off your tap and even node but doesn't sound like its that bad or they would have seen it with other modems dropping in your area. I would check all your outlets that are active and make sure all connections are tight and that there are no unterminated active cables laying around anywhere.


djrobx
Premium
join:2000-05-31
Valencia, CA
kudos:2
Reviews:
·Time Warner Cable
·VOIPO
reply to etaadmin

The signal level immediately from the node is always high so the node will be a able to feed everyone to the end of the trunk. So to achieve the 'target' level for the first customer in the line (people closer to the node) a high level attenuation tap should be used but this attenuation is not unidirectional (upstream and downstream) it affects both signals the same way so the modem to compensate for the added attenuation it has to increase its power output (upstream).

I had to think about this one. At first I thought attenuation being equal it wouldn't matter. Either you have attenuation from cable length, or you have artificial attenuation added from a high value tap.

Then I realized that cable-length attenuation impacts higher frequencies (where the downstreams are) more than low frequencies (where the upstreams are).

»www.w4rp.com/ref/coax.html

That means if attenuation is added to each tap that "targets", say, 0db at 500mhz, the upstream will skew stronger (lower modem output levels needed) as you go further away from the amp/node.
--
AT&T U-Hearse - RIP Unlimited Internet 1995-2011
Rethink Billable.

etaadmin

join:2002-01-17
Dallas, TX
kudos:1
said by djrobx:

The signal level immediately from the node is always high so the node will be a able to feed everyone to the end of the trunk. So to achieve the 'target' level for the first customer in the line (people closer to the node) a high level attenuation tap should be used but this attenuation is not unidirectional (upstream and downstream) it affects both signals the same way so the modem to compensate for the added attenuation it has to increase its power output (upstream).

I had to think about this one. At first I thought attenuation being equal it wouldn't matter. Either you have attenuation from cable length, or you have artificial attenuation added from a high value tap.

Then I realized that cable-length attenuation impacts higher frequencies (where the downstreams are) more than low frequencies (where the upstreams are).

»www.w4rp.com/ref/coax.html

That means if attenuation is added to each tap that "targets", say, 0db at 500mhz, the upstream will skew stronger (lower modem output levels needed) as you go further away from the amp/node.

I had to think about this one too But there is another variable that we havent taken into consideration and that is the variable gain in the receiver (downstream) This number can take any value (gain) between -15 to +15 dBmV. I don't work in the cable industry so I don't know the details but from my experience I would extrapolate this sub-system as some sort of AGC (automatic gain control) ... well sort of.

The optimum value for the 'operating level range' as some motorola documents call it is 0dBmV, this means (to me) that the modem can compensate better in case the signal is too strong or too weak. The 'operating level range' can fine tune the receiver's gain in case the tap value is not an exact match. I'm sure taps come in standard values »www.taiwantrade.com.tw/tcc/produ···S/198003

quote:
Tap values available:11dB to 35dB in 3dB steps

So if a cable guy needed a 12.5db tap he would have to choose a 11db or a 14db tap. Unmatched taps could influence upstream power output too.

Another thing, the cable types used in comercial and HAM radio like in Richard's site (the link that you posted) are not the same used by CATV. I don't know the specifics or the type of cable but from what I've seen it looks like a ~1 inch in diameter hardline type of cable with a thick ~1/8 in. aluminum jacket. »www.therfc.com/hardline.htm I'm sure that this type of cable has a much better RF characteristics and lower attenuation than those used in HAM radio.

SanAntonioTx
Premium
join:2008-07-18
Venice, CA
reply to G0d
only person on my tap is me LOL its deddicated to ONLY me LOL not even my neighbor has it

RoadRunner79

join:2008-01-19
San Antonio, TX
reply to SanAntonioTx
There was a time years ago we had the whole house wired up for TWC triple play which was four rooms, digital phone and at the time 2 year contract for 20/2 service here in san antonio. a couple of years went by without RR in the house. fast forward to now, we have only 50/5 ultimate package through a SBG6580 modem. It is coming off the tap through a double side male connector thats grounded and from there it goes to a splitter labeled broadband.

If I take the coax line off the splitter and connect it to the house side of that double sided male connector will the modem work better? Will that be considered direct connect???

OP that is beautiful ping I'm over by culebra and callaghan and ping never been lower than 50.

Thanks guys.


Jabbu
Premium
join:2002-03-06
That would be direct connect, if you remove the line going to the modem off a splitter and connect it right to the ground block. If you have no issues with wiring inside, and twc has a good line outside, you should not see any benefit to doing this. It would not hurt to post your signal levels.