downstream power level?

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Greg

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Dec 21, 2004, 12:01:38 PM12/21/04
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What is the typical downstream power level for a cable modem?
My modem seems OK although I don't really know what the performance is. My TV
channels 2-6 suck. I know this is the same band. My modem says 3dB. Is that
low? Can it tolerate a bump up to improve the TV signal?

BigJIm

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Dec 21, 2004, 12:37:19 PM12/21/04
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some of my channels suck that is why I have satellite with the local
channels.
I also have broadband, wish I could get dsl and completely rid myself of
Comcast.
as far as your problem it is probably a line issue, bad connector or
something.
"Greg" <gfre...@aol.com> wrote in message
news:20041221120138...@mb-m23.aol.com...

Bit Twister

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Dec 21, 2004, 1:53:09 PM12/21/04
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On 21 Dec 2004 17:01:38 GMT, Greg wrote:
> What is the typical downstream power level for a cable modem?
> My modem seems OK although I don't really know what the performance is. My TV
> channels 2-6 suck.

Have see people with good tv signal and poor internet cable values.
Internet drop outs/failures users also had poot tv.

If no problems with internet, then I would check tv path.

> I know this is the same band. My modem says 3dB. Is that low?

Hmmm, mine i -1dbv.

> Can it tolerate a bump up to improve the TV signal?

Look up the specs on your cable modem.

I would not recommend you placing an amp in front of your cable modem.

Andrew Rossmann

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Dec 21, 2004, 4:30:38 PM12/21/04
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[This followup was posted to comp.dcom.modems.cable and a copy was sent
to the cited author.]

In article <20041221120138...@mb-m23.aol.com>,
gfre...@aol.com says...

Does your cable modem list the downstream and upstream frequencies?
Most commonly, downstream will be very high, like in the 600-700's. That
is well into the UHF channels (or cable channels 85+). Channels 2-6 are
roughly 50-88MHz. Upstream usually uses frequences below 50.

+3db is good. The recommendation is +15 to -15, although some
recommend trying to keep it +8 to -8. You also need to check SNR (Signal
to Noise Ratio). It should be 30+. Upstream should be below 55db.

http://www.speedguide.net/read_articles.php?id=1197

Noise and problems with channels 2-6 often mean a poor cable ground
someplace. Double-check all your connections. Also, verify that any
splitters are rated 5-900 or 5-1000. Replace any that are unrated, or
start at 40 or 50MHz.

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Greg

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Dec 21, 2004, 5:22:38 PM12/21/04
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Thanks Andy, I am in the process of swapping out all of the cable on my side
with brand new quad shield. I have a "real" crimper and I am using good
connectors. We will see.
So far I have found some questionable stuff so I do have some confidence I am
fixing something
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