NoProxy
join:2002-01-04
| [COMCAST] signal strength/HDTV & Internet question
I have my cable internet off the first split coming into my house, I am thinking of upgrading to digital HDTV, my main TV is off a 3rd splitter. I just hooked my cable modem up to this and everything works great passing through all 3 splitters so I assume I'm getting 2 way communications through all 3 splitters?
does this mean HDTV and VOD will work off my 3rd splitter?
are these good numbers for HDTV/ VOD to work without problems even at -10db?
The reading off the 3rd splitter on my cable modem is:
36 SNR downstream power level -10db
upstream power level is 58
The reading off my first splitter was
38 SNR downstream power level -2db
upstream power level 54 |
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jim shooz
join:2003-01-29
Evansville, IN
| Modern day cable codes say all of the outlets should be "home runs", that is the only splitter should be the one outside. It would be to your benefit to have the outlets re-ran that are going to digital boxes, hdtv boxes, and cable modems so that they are home runs. Your cable company will probably run a new outlet for you when you upgrade. As far as your original question, your modem and hd signals will run at a different frequency. Just because your modem isn't having any problems, doesn't mean your hdtv won't. In my opinion, modems tend to work with lower signal than most converter boxes. |
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kcharg
Kcharg
Premium,VIP
join:2000-10-28
Forney, TX
| reply to NoProxy
said by NoProxy  :
I have my cable internet off the first split coming into my house, I am thinking of upgrading to digital HDTV, my main TV is off a 3rd splitter. I just hooked my cable modem up to this and everything works great passing through all 3 splitters so I assume I'm getting 2 way communications through all 3 splitters?
does this mean HDTV and VOD will work off my 3rd splitter?
are these good numbers for HDTV/ VOD to work without problems even at -10db?
The reading off the 3rd splitter on my cable modem is:
36 SNR downstream power level -10db
upstream power level is 58
The reading off my first splitter was
38 SNR downstream power level -2db
upstream power level 54
You should try and put that off of the first or second splitter as well. The DCT does act much like a cable modem in the sense that it has to talk back to the head-end. Our DCT's have problems when the return is more than 50db, now the modems have issues with a power level more than 55db. I would replace your first splitter with a 3-way splitter and run one line to the modem and one line to your cable modem and the last one going to other splitters for TV's.
kcharg
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kcharghttp://home.attbi.com/~kcharg/ |
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NoProxy
join:2002-01-04
1 edit | said by kcharg :
I would replace your first splitter with a 3-way splitter and run one line to the modem and one line to your cable modem and the last one going to other splitters for TV's.
kcharg
I'll give that a try, use a 3 way splitter with one feeding my modem, one feeding my HDTV box and the other to a 3 way splitter for the others. I am just wondering which should get the strongest feed?
Is -8 or -10db OK for the digital HDTV box? I think I will run the Modem and HD box off the 2 -7db and the rest of the Anolog tv's off the -3.5db.
I guess this setup gives me a "home run" to the Cable Modem and HD Box, I hope it works out. |
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djrobx
join:2000-05-31
Valencia, CA
 ·PHONE POWER
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1 edit | reply to NoProxy
Although the folks around here seem to like sending the hottest signal to the cablemodem, I've personally found it to be the most resilient to a weak signal. Unless you're losing sync and are having problems, you'll probably see the same speeds whether it's on the strongest or weakest tap.
TV, on the other hand, you visibly see the degradation on analog stations, and the most minor losses are so visible on digital channels, especially HDTV. I would personally send the hottest tap to where you need to split again
Be aware that many 3 tap splitters are really functionally equivalent to two 2 tap splitters. Those types of splitters usulaly have two taps at -6 and another at -3. The two diagrams posted above would be nearly identical in function if you had one of those types of three output splitters. And, as mentioned above, I think that's desirable since the room with the extra spilts needs a little more strength.
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\\ROB - a part of the SCB local network |
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NoProxy
join:2002-01-04
| reply to kcharg
I did what you all thought was better and my signal strength and power level improved on everything, I guess it is better to use a 3 way splitter than two 2 way splitters:)
I'm currently running my cable modem of the 7db port and the SNR is 38 Power level is -4dBmV my upsteam power level is 56
The 3.5db port is even better snr 38 -1dBmV and upstream power level is 53 (I may use this for the rest of my analog TV's)
The other 7db port is running -5dBmV snr 38 and upsteam power level is 56 will this one work for my HDTV box?? is the 56 upstream power level too high? |
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lumpy9138
Premium
join:2003-12-19
Elgin, IL | Yes, more than likely will have intermittent return issues at that high a level. |
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