SNR and Signal Level Protocol w/CC

[Bee_Dee_3_Dee]

I'm planning on calling my Cable company back today. I still need better SNL and Signal Levels after they improved things already. So I need to know a little more about SNR and Signal Level (Protocol with my Cable company Brighthouse) than what I have picked up on so far since discovering how to read the levels yesterday.

(Yesterday I read for the 1st time, " SNR and Signal Level explained": http://www.cetoncorp.com/support/index. ... -explained ". And I started to master the part of the WMC plug-in for reading SNR and Signal Level.)

Yesterday, Brighthouse did a great job responding to my request(s). I called them in mid-afternoon. A service man arrived in under 90 minuets.

After testing all points, he said that they were fine (consistent) and therefore the weak signal and poor SNR was being caused further on beyond the connection that led from the telephone pole to my house. And that the weak signal and poor SNR would be resolved within 24 hours; after another service man was notified to diagnose and resolve it.

And low and behold, at 8:00 am today my SNR and Signal Levels were greatly improved. But nowhere near perfect.

SNL is presently averaging 33 dbmV. Whereby yesterday the average was below 28. And Signal Level is still averaging just -18 db.

Shouldn't Brighthouse Cable company improve my SNR and Signal Levels?

Thanks!

Edit 1: Should I just request they run a dedicated cable? (My Ceton device is fed from a cable that goes to a three or four way splitter in the box attached to my house.)

[erkotz]

A dedicated cable should not be necessary to feed the InfiniTV. How many splits are between the pole and the InfiniTV? You lose 3.5dB for each split - so if you have a lot, may need an amplifier.
I realize I'm not normal, but in my house I have a total of about 60 ports, including one 32-way splitter, running all off a single feed from Time Warner (and an amp from Toner Cable)

[Bee_Dee_3_Dee]

A dedicated cable should not be necessary to feed the InfiniTV. How many splits are between the pole and the InfiniTV? You lose 3.5dB for each split - so if you have a lot, may need an amplifier.
I realize I'm not normal, but in my house I have a total of about 60 ports, including one 32-way splitter, running all off a single feed from Time Warner (and an amp from Toner Cable)

A dedicated cable should not be necessary to feed the InfiniTV. How many splits are between the pole and the InfiniTV? You lose 3.5dB for each split - so if you have a lot, may need an amplifier.
I realize I'm not normal, but in my house I have a total of about 60 ports, including one 32-way splitter, running all off a single feed from Time Warner (and an amp from Toner Cable)

cool. Thanks for the info, erkotz.

There are no splits between the pole and InfiniTV; other than the cable goes from the pole to the box on my house; but inside the box the cable has a splitter that sends it to three TVs including my InfiniTV.

At 12:15 pm today things started looking bad so I noted the following:

Date: 20130220_1215 (12:15 pm)
Starting with 1003, the following are not working:
1003 pixels (SL: -19 dbmV SNR: 30 db)
1012 pixels (SL: -19 dbmV SNR: 30 db)
1107 pixels (SL: -19 dbmV SNR: 30 db)
1127 pixels (SL: -19 dbmV SNR: 30 db)
1135 pixels (SL: -20 dbmV SNR: 28 db)
1136 pixels (SL: -20 dbmV SNR: 29 db)
1138 pixels (SL: -19 dbmV SNR: 30 db)
1139 pixels (SL: -18 dbmV SNR: 31 db)
1140 pixels (SL: -20 dbmV SNR: 30 db)
1401 pixels (SL: -20 dbmV SNR: 29 db)
1402 pixels (SL: -20 dbmV SNR: 29 db)
1403 pixels (SL: -20 dbmV SNR: 27 db)
1404 pixels (SL: -20 dbmV SNR: 29 db)
1412 pixels (SL: -05 dbmV SNR: 39 db)
1418 pixels (SL: -20 dbmV SNR: 30 db)
1429 pixels (SL: -19 dbmV SNR: 30 db)
1432 pixels (SL: -06 dbmV SNR: 38 db)
1142 SU (SL: -21 dbmV SNR: 26 db)
1144 pixels (SL: -20 dbmV SNR: 29 db)
1147 pixels (SL: -18 dbmV SNR: 31 db)
1148 pixels (SL: -18 dbmV SNR: 31 db)
1603 pixels (SL: -18 dbmV SNR: 31 db)

But, just like the Brighthouse tech said yesterday, around 4:00 pm, "[..in 24 hours or less, everything would be up 5 db after another tech in charge of that (signals down the line from the pole) looked into it]", and everything is improved 5 db.

BUT, my Signal Levels aren't near 0 dbvM. They are about -14 dbvM average now. (Yes my SNR are back to between 32 and 35. And that's cool.)

And I'd like to know,
Should I try and get my cable company to get my Signal Levels near 0 dbvM?
(versus the -14 dbvM average they are at now.)

After all, that's what it suggests:
" SNR and Signal Level explained": http://www.cetoncorp.com/support/index. ... -explained ".

Thanks again!

[Paw Paw]

Here are a couple of suggestions on how I troubleshoot my cable system

Go over to the Windows Expert Community site and get a copy of the “AllCetron Signal.txt” file. Here is the URL
http://experts.windows.com/frms/windows ... ageIndex=2
The file is in the second post on the page. I find it to be a very valuable tool at trouble shooting signal and SNL levels. Read the posts in the thread to learn about the tool. It will give you a profile of all of the frequencies that the cable company is using.

If the “Cable Guy” claims that the signals are “good at the poll” you probably need to verify this for yourself. To do this I have actually moved my HTPC out to the cable drop and plugged the cable coming from the poll directly into my HTPC. Another option would be to buy a long piece of RG6 coax that would reach from your HTPC to the cable drop and bypass the existing premises wiring to test the signals. If your signals are good at this point then you have a premises wiring problem. If not it is a cable company problem.

If it is a premises wiring issue then the first thing to check is the grounding block where the cable enters your house. I have had problems with the connectors on the grounding block because it is exposed to the elements. The last time the cable company reterminated the grounding block they finally used outside connectors with a protective boot.

The second most likely source of signal loss is the connectors on the coax. If you have any twist on or crimp type connectors they should be replaced with compression fittings.

Another source of signal loss would be a bad splitter. Check the splitter and make sure that it is rated for at least 750 Mhz and preferably 1,000 Mhz. If not, replace the splitter.

The only other source of signal loss that I can think of is bad coax. When I went to a digital system I replace all of the coax in my house. I had some old RG59 coax and some substandard RG6 coax and splitters all over the place. I replaced every run in the house with compression fillings and RG6 Quad shielded coax back to a central point where I installed an amplifier and a splitter large enough to support all of my TVs. It was a PITA and took several weekends with my son helping me but I have not had a premises wiring issue since then.

[Bee_Dee_3_Dee]

Here are a couple of suggestions on how I troubleshoot my cable system

Go over to the Windows Expert Community site and get a copy of the “AllCetron Signal.txt” file. Here is the URL
http://experts.windows.com/frms/windows ... ageIndex=2
The file is in the second post on the page. I find it to be a very valuable tool at trouble shooting signal and SNL levels. Read the posts in the thread to learn about the tool. It will give you a profile of all of the frequencies that the cable company is using.

If the “Cable Guy” claims that the signals are “good at the poll” you probably need to verify this for yourself. To do this I have actually moved my HTPC out to the cable drop and plugged the cable coming from the poll directly into my HTPC. Another option would be to buy a long piece of RG6 coax that would reach from your HTPC to the cable drop and bypass the existing premises wiring to test the signals. If your signals are good at this point then you have a premises wiring problem. If not it is a cable company problem.

If it is a premises wiring issue then the first thing to check is the grounding block where the cable enters your house. I have had problems with the connectors on the grounding block because it is exposed to the elements. The last time the cable company reterminated the grounding block they finally used outside connectors with a protective boot.

The second most likely source of signal loss is the connectors on the coax. If you have any twist on or crimp type connectors they should be replaced with compression fittings.

Another source of signal loss would be a bad splitter. Check the splitter and make sure that it is rated for at least 750 Mhz and preferably 1,000 Mhz. If not, replace the splitter.

The only other source of signal loss that I can think of is bad coax. When I went to a digital system I replace all of the coax in my house. I had some old RG59 coax and some substandard RG6 coax and splitters all over the place. I replaced every run in the house with compression fillings and RG6 Quad shielded coax back to a central point where I installed an amplifier and a splitter large enough to support all of my TVs. It was a PITA and took several weekends with my son helping me but I have not had a premises wiring issue since then.

AWESOME! Thanks Paw Paw.

i'll tackle the DCT Diag application first. (and post my results.)

Then I need to research much of the terminology used in ur post. (I'm an extremely experienced and knowledgeable computer tech. But I know nothing about TV technology.) My lack of TV knowledge and experience is why I started this thread. And ur post (and erkotz's) are exactly what I was hoping for. Thanks again!

[erkotz]

How many splitters do you have before the InfiniTV - most likely the tech meant that the feed to your house would be 0dB.

[Paw Paw]

What I was trying to say was that if the signal levels and SNLs were within Ceton specs (+12db to -12dm) where the cable enters his house (premises) then the problem is in his house wiring but if the signal levels and SNL are out of spec there the problem is on the Cable Company’s equipment. 0db is what they shoot for but anything within the spec is OK with them.

My HTPC is downstream of a +16db amp and one split -3.5db plus about 100 feet of RG6 Quad cable. Backing out these factors the cable company is probably giving me about a +0db signal at the lower frequencies and a -8 db signal at 750 mhz where they enter my house. However, with my amp, I have plenty of signal at my HTPC to support the Ceton tuner.

In order to fix his problem with -18db signal levels he first needs to determine if it is in his house wiring or if the Cable Company is not providing an adequate signal. I have NEVER trusted the “Cable Guy”. Some of them are really great and know what they are doing but some of them will “blow smoke” at you. So the first step in trouble shooting is to accurately determine if it is their problem or a problem with the connectors, cable or splitters in your house.

[Bee_Dee_3_Dee]

How many splitters do you have before the InfiniTV - most likely the tech meant that the feed to your house would be 0dB.

i forgot to mention before, that i have one splitter inside that is two feet from HTPC and goes to two short cables. One cable goes to the TA and the other to my InfiniTV. i also forgot in my first couple of posts, to praise the cable guy for replacing that splitter and both of the short cables with brand new ones. the existing were very poor quality and old.

and before, when i mentioned the cable box on my house, i thought that there were two cables from the pole. But there's just one cable from the pole to the box on house. then inside the box there are two splitters.

as far as what the tech promised. all he said was that SNR and SL would improve by 5 db. And they did. But at that time i was just starting to understand things. and it's why i started this thread.

See, i did mention to the cable guy the whole "SNR and Signal Level explained": http://www.cetoncorp.com/support/index. ... -explained. I read the 3rd paragraph to him while i pointed to it on a 27' display. And he understood what it was explaining. Before he left i reiterated the acceptability of combinations of High SNR with Low SL or Low SNR and High SL. And he comprehended it very well.

But my SL are still pretty sad. About -12 dbmV at best.

Edit 1: And thanks again erkotz. i really appreciate ur help.

[Bee_Dee_3_Dee]

What I was trying to say was that if the signal levels and SNLs were within Ceton specs (+12db to -12dm) where the cable enters his house (premises) then the problem is in his house wiring but if the signal levels and SNL are out of spec there the problem is on the Cable Company’s equipment. 0db is what they shoot for but anything within the spec is OK with them.

My HTPC is downstream of a +16db amp and one split -3.5db plus about 100 feet of RG6 Quad cable. Backing out these factors the cable company is probably giving me about a +0db signal at the lower frequencies and a -8 db signal at 750 mhz where they enter my house. However, with my amp, I have plenty of signal at my HTPC to support the Ceton tuner.

In order to fix his problem with -18db signal levels he first needs to determine if it is in his house wiring or if the Cable Company is not providing an adequate signal. I have NEVER trusted the “Cable Guy”. Some of them are really great and know what they are doing but some of them will “blow smoke” at you. So the first step in trouble shooting is to accurately determine if it is their problem or a problem with the connectors, cable or splitters in your house.

exactly! (ur suggested first step in trouble shooting sounds very accurate and logical. everything u say is helpful/awesome. Thanks!)

possible tools:
-I can schedule another cable guy next week
-pick Tier three support brains on the phone
-find a Genie and make a wish

a few days ago i deduced that joining forums at TheGreenButton and picking some brains would be a good idea. i'm glad i did!

i just need to remember my problem is as simple as, "Low Signal Levels".

Edit 1:
i forgot to mention that i still need to complete running the DCT Diag application on all tuners. That will absolutely be part of the algorithm(s) formed from the two tools i listed.

[Paw Paw]

You mentioned 2 splitters in the cable box and another near the HTPC. Are these 2 way splitters, 3 way, 4 way? For every 2 way splitter you lose about 3.5 db in signal strength. For a 3 or 4 ways splitter assume 7 db of loss and for an 8 way spllitter about 14 to 15 db of loss.

Assuming all of yor splitters are all 2 way splitters and they are all in the circuit to your HTPC that is over 10 db of signal loss just from the splitters and might account for your problem. I still recommend checking the signal levels by connecting your HTPC directly to the incomming cable and bypassing all premiss wiring to get an accurate reading of what the cable company is delivering to you. If the cable signals are withinn spec then you might need to install an amplifier. The amplifier should be installed before any of the splitters so you are amplifying the best signal. However, check out your premiss wiring first. Maybe some of those splitters are not needed. In my mother's condo every outlet was connected to the cable even though she did not use 4 of them. By eliminating the unneeded splitters I was able to gain 7 db of signal strength at no cost.

Good Luck

[Paw Paw]

I forgot to mention that if you have a cable modem the amplifier should not be in the circuit to the modem. In that case you would have one split at the cable box to feed the modem and then the other side of the splitter would feed the amplifier and then all of your TVs and the HTPC. Also, some cable companies will supply an amplifier at no cost while others will charge you for it. You can also purchase you own amplifier but don't skimp on quality.

[Bee_Dee_3_Dee]

You mentioned 2 splitters in the cable box and another near the HTPC. Are these 2 way splitters, 3 way, 4 way? For every 2 way splitter you lose about 3.5 db in signal strength. For a 3 or 4 ways splitter assume 7 db of loss and for an 8 way spllitter about 14 to 15 db of loss.

Assuming all of yor splitters are all 2 way splitters and they are all in the circuit to your HTPC that is over 10 db of signal loss just from the splitters and might account for your problem. I still recommend checking the signal levels by connecting your HTPC directly to the incomming cable and bypassing all premiss wiring to get an accurate reading of what the cable company is delivering to you. If the cable signals are withinn spec then you might need to install an amplifier. The amplifier should be installed before any of the splitters so you are amplifying the best signal. However, check out your premiss wiring first. Maybe some of those splitters are not needed. In my mother's condo every outlet was connected to the cable even though she did not use 4 of them. By eliminating the unneeded splitters I was able to gain 7 db of signal strength at no cost.

Good Luck

I forgot to mention that if you have a cable modem the amplifier should not be in the circuit to the modem. In that case you would have one split at the cable box to feed the modem and then the other side of the splitter would feed the amplifier and then all of your TVs and the HTPC. Also, some cable companies will supply an amplifier at no cost while others will charge you for it. You can also purchase you own amplifier but don't skimp on quality.

i'm just getting back to tweaking my Ceton. because i was busy fixing a kitchen faucet yesterday.lol

the cable box on my house has a couple of 3 way splitters. Next to the HTPC is just a single 2 way splitter. My internet is dedicated from the box on my house.

[Bee_Dee_3_Dee]

i just scheduled a "Quality Check" for Signal level (and SNR) for this Monday. The Tier 3 support phone rep did a great job of providing information and answering questions. He sees -10 dbmV from the cable going to my Ceton. My ruff estimate is and average of -13 dbmV. He noted -6 dbmV is going to a Scientific America DVR in my house. So i should remember that. Because it would be awesome to get just as good a signal going to my Ceton InfiniTV!

(i still have to complete all tuner scan with DCT Diag application. but there have been too many great sporting events to watch/ record! )

The "Quality Check" this Monday will include: a request (by the cable guy that shows up) that the ppl that already worked on tweaking from the Tap to the Node last Wednesday and Thursday, do some follow-up tweaking. YAY!

So even though my dilemmas continue, there is no reason to believe that signals won't be improving.

[Paw Paw]

OK I think I have a better idea of your wiring. The levels that the phone tech measured at your S/A DVR and TA make sense. Since there is one more split just before the TA.

I would bet that on Monday the tech finds that the signal coming from the cable company is in spec.

If he checks all of the splitters and connectors and they are all good then he will probably recommend an amplifier to boost the signal levels to your TVs. Hopefully he can install one at no cost or minimal cost to you.

By changing your configuration in the cable box to a 2 way splitter with one side going to your cable modem and one side to a +16db amp and then placing a 4 way splitter just downstream from the amp to feed the TVs and Ceton Card you could pick up 19.5 db and go from a -13 db level to a +6.5 db signal level at the Ceton Card.

Good Luck

[Bee_Dee_3_Dee]

OK I think I have a better idea of your wiring. The levels that the phone tech measured at your S/A DVR and TA make sense. Since there is one more split just before the TA.

I would bet that on Monday the tech finds that the signal coming from the cable company is in spec.

If he checks all of the splitters and connectors and they are all good then he will probably recommend an amplifier to boost the signal levels to your TVs. Hopefully he can install one at no cost or minimal cost to you.

By changing your configuration in the cable box to a 2 way splitter with one side going to your cable modem and one side to a +16db amp and then placing a 4 way splitter just downstream from the amp to feed the TVs and Ceton Card you could pick up 19.5 db and go from a -13 db level to a +6.5 db signal level at the Ceton Card.

Good Luck

cool!

i'll start by asking the tech to help me diagram exactly wat is wat. hopefully he'll be a wizard and wave a magic wand "poof!".

and i'll quote wat u say:
..."[change the] configuration in the cable box to a 2 way splitter with one side going to [the] cable modem and one side to a +16db amp and then placing a 4 way splitter just downstream from the amp to feed the TVs and Ceton Card you could pick up 19.5 db and go from a -13 db level to a +6.5 db signal level at the Ceton Card".

tanks!

or maybe if he is NOT a wizard, i can just request that he swap (from the cable box) just the two cables going to the Ceton and the Scientific America DVR. Then make sure the signal is still -6. Because i don't think the scientific DVR needs a signal any better than wat my Ceton is getting.

i don't have an amp yet... i thought i had one. but i've misplaced it. i only found the original box. i might get lucky and find it. it's a Recoton V312UL 4-way Distribution Amplifier. Is that any good?

[Paw Paw]

That amp is not satisfactory even if you find it. First it only has +10 db of gain and I would recommend a +16db amp. Also it is only rated to 450 Mhz. That was good enough for the older cable systems but most systems now go up to 750 Mhz or 1,000Mhz so you can stop looking for it.

Swapping out the S/A DVR and TA lines will have no impact on the signal level at the TA and Ceton. The TA measures a lower signal because of the 2 way splitter connecting the Ceton and TA to the cable line.

Since you stated that you have two 3 way splitters in your cable box I assume that you are feeding a cable modem, S/A DVR, Ceton/TA and two other TVs. If you do not have the 2 other TVs then a 2 way splitter or imbalanced 3 way splitter could be employed downstream of the amplifier rather than a 4 way and get you another 3.5 db of improved signal level.

FYI: There are two types of 3 way splitters. An imbalanced 3 way has one port with -3.5db of loss and two ports with -7 db of loss. A balanced 3 way splitter has -7 db of loss on all 3 ports.

[Bee_Dee_3_Dee]

Tthat amp is not satisfactory even if you find it. First it only has +10 db of gain and I would recommend a +16db amp. Also it is only rated to 450 Mhz. That was good enough for the older cable systems but most systems now go up to 750 Mhz or 1,000Mhz so you can stop looking for it.

Swapping out the S/A DVR and TA lines will have no impact on the signal level at the AT and Ceton. The TA measures a lower signal because of the 2 way splitter connecting the Ceton and TA to the cable line.

Since you stated that you have two 3 way splitters in your cable box I assume that you are feeding a cable modem, S/A DVR, Ceton/TA and two other TVs. If you do not have the 2 other TVs then a 2 way splitter or imbalanced 3 way splitter could be employed downstream of the amplifier rather than a 4 way and get you another 3.5 db of improved signal level.

FYI: There are two types of 3 way splitters. An imbalanced 3 way has one port with -3.5db of loss and two ports with -7 db of loss. A balanced 3 way splitter has -7 db of loss on all 3 ports.

i'll remember to mention this addition info to the cable guy too. i think i'll just print this entire thread. and highlight the stuff i want to remember to mention on Monday.

thanks!

[Crash2009]

Here is a diagram of one way to get what you want. This amp is a +10, not necesarily what you need. You can also get these amps with zero loss or gain. Show the picture to your cable guy and ask him what you need. 0, +10, +16

[Bee_Dee_3_Dee]

Here is a diagram of one way to get what you want. This amp is a +10, not necesarily what you need. You can also get these amps with zero loss or gain. Show the picture to your cable guy and ask him what you need. 0, +10, +16

cool. thanks for the info!

[Bee_Dee_3_Dee]

Just before the cable guy arrived a couple hours ago, i finally figured out how to accomplish Paw Paw's 1st suggestion. The “AllCetron Signal.txt” file" thing.

it worked great. (ty ty ty, Paw Paw!)

See:


I showed it to the cable guy...
... but before that, he mentioned a dispatcher had just noted to him on the phone as he arrived that even MORE missing codes had been added to my television account today. Originally they thought (going on three weeks ago) that all the ones missing, had all been successfully added. but i guess they missed a few more.

So, back to the SNL and signal and what the cable guy did today...

...well it was mostly adding an amp. Paw Paw said that, "...some cable companies will supply an amplifier at no cost...". And they DID. w00t!

i have to mention that i really appreciate all the incite gained from erkotz's posts. ty ty ty, erkotz!

and that one diagram from Crash2009 was spot on. ty ty ty, Crash2009!

the diagram looks just like wat i got, but mine has a single out on it. and the coaxial cable used for power; well, thanks to having already seen it in the diagram, i didn't freak out out when he hooked it up.

it's a PCT-MA2-M. like here:

http://pctcorporate.com/images/stories/ ... 21025c.pdf

i showed the cable guy most of everything on this thread too.

AND so my new “AllCetron Signal.txt” file" thing test results are awesome! (see just below.) or at least i think they are. it's a start.

see:


thanks again ppl here on The GreenButton for all the help. i really appreciate it!

aren't my new numbers good?

or are they great?