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DrDrew
That others may surf
Premium
join:2009-01-28
SoCal
kudos:15
reply to bspencer

Re: Forward Path Attenuators

said by bspencer:

said by digiblur:

said by kilrathi:

Yes but it does help if your downstream power level is too hot.

Put it behind a splitter. That's rarely the problem though.

I plan on installing the amp as follows:

Wall---Splitter---Amp---Cable Modem

whats the splitter for? Previously you said your modem was on a direct line with no splits...
--
If it's important, back it up... twice. Even 99.999% availability isn't enough sometimes.

bspencer

join:2012-10-17
Foothill Ranch, CA

said by DrDrew:

whats the splitter for? Previously you said your modem was on a direct line with no splits...

The best quality line in my house happens to go directly from the street to my cable phone modem. I split that line and attached my cable modem.


DrDrew
That others may surf
Premium
join:2009-01-28
SoCal
kudos:15

Is the phone modem showing the same signals? Is the splitter just a 2 way splitter? Did cox install both and the splitter?


bspencer

join:2012-10-17
Foothill Ranch, CA

said by DrDrew:

Is the phone modem showing the same signals? Is the splitter just a 2 way splitter? Did cox install both and the splitter?

I haven't been able to view the signal on the phone modem. I installed the splitter, but it was one that the technician left for me in case I needed it for anything else.

bchandler02

join:2011-07-08
Oklahoma City, OK
reply to bspencer

That alone could be a MAJOR part of your problem. Between the wall and the modem there should be no splitter. Cable modems should have a direct line ran for them.

In your box outside, you should either have 1) a direct line to your cable modem, if no other cox services (jacks) used, or 2) incoming line --> 2 way splitter --> 1 to cable modem, the other to everything else (and an additional splitter if needed)


bspencer

join:2012-10-17
Foothill Ranch, CA

said by bchandler02:

That alone could be a MAJOR part of your problem. Between the wall and the modem there should be no splitter. Cable modems should have a direct line ran for them.

In your box outside, you should either have 1) a direct line to your cable modem, if no other cox services (jacks) used, or 2) incoming line --> 2 way splitter --> 1 to cable modem, the other to everything else (and an additional splitter if needed)

Hopefully this can still be overcome by using the Active Return amp.

bspencer

join:2012-10-17
Foothill Ranch, CA
reply to bspencer

Today my upstream is showing as follows. However, I'm sure that 58 dBmV will be right around the corner sometime.

Channel ID 3
Frequency 35580000 Hz
Ranging Service ID 882
Symbol Rate 2.560 Msym/sec
Power Level 49 dBmV
Upstream Modulation [2] QPSK
[3] 16QAM

Ranging Status Success

Still interested in whether 16QAM is good or can be improved.


bspencer

join:2012-10-17
Foothill Ranch, CA

1 edit
reply to bspencer

I received and installed my Active Return amp. Here are my signal strengths now.

Downstream
Channel ID 199 200 201
Frequency 579000000 Hz 585000000 Hz 591000000 Hz
Signal to Noise Ratio 37 dB 37 dB 38 dB
Downstream Modulation QAM256 QAM256 QAM256
Power 5 dBmV 5 dBmV 5 dBmV

Upstream
Channel ID 3
Frequency 35580000 Hz
Ranging Service ID 882
Symbol Rate 2.560 Msym/sec
Power Level 42 dBmV
Upstream Modulation [2] QPSK [3] 16QAM

I feel that these are really good signals. I'll let you know if I experience cable modem resets.

I've seen my upstream QAM be as high as 64 even when I didn't have the amp installed. Any idea what that value means and how to get the best possible value? I read the FAQ at »Comcast High Speed Internet FAQ »What is QAM? and it would seem that the higher the QAM, the better.


lilstone87

join:2009-04-09
Portsmouth, VA
kudos:3

With 64QAM on the upstream, there is about twice as much available bandwidth on the upstream channel. However 64QAM doesn't play nice with noise, so the modem will drop to 16QAM. As 16QAM works better when there is a active noise issue appearing.



digiblur
Premium
join:2002-06-03
Louisiana
reply to bspencer

Cox would be at my house everyday replacing pieces if I had to use an amp to get my modem signals right. There should be no reason that an amp is required.



bbeesley
VIP
join:2003-08-07
Richardson, TX
kudos:5

said by digiblur:

There should be no reason that an amp is required.

If your house were large enough that a run to a TV was greater than a few hundred feet post ground block, then an amp would be an excellent solution

I do agree that it is counterproductive to use amps on data/phone drops however.

bspencer

join:2012-10-17
Foothill Ranch, CA
reply to digiblur

said by digiblur:

Cox would be at my house everyday replacing pieces if I had to use an amp to get my modem signals right. There should be no reason that an amp is required.

COX has been to my house countless times. They fix something either at the street or in my house and within a month or two the issues are back. I'm tired of chasing my tail and that's why I went the amp route. I'm happy at this point.


digiblur
Premium
join:2002-06-03
Louisiana
reply to bbeesley

said by bbeesley:

said by digiblur:

There should be no reason that an amp is required.

If your house were large enough that a run to a TV was greater than a few hundred feet post ground block, then an amp would be an excellent solution

I do agree that it is counterproductive to use amps on data/phone drops however.

TV, I could understand as at one time I had like 7 or 8 drops for TVs and tuners and needed an amp. I had the amp after the initial 2 way split for the cable modem though.

bspencer

join:2012-10-17
Foothill Ranch, CA
reply to bspencer

Now that I've got my cable modem resets under control, do you think that I would get even more benefit from using a Forward Path Attenuator to get my downstream power closer to zero?