Signal levels

[ollie2001]

I've noticed my signal levels on my 255 Cable Modem are a little wonky and that I never seem to manage a 20mb connection at any time of the day. What do you think would be the easiest way of getting a Tech out to have a look? I'm not too keen on ringing tech support as they'll blame my PC and tell me the signal levels are fine (or that I shouldn't even know what signal levels are!)

Here they are:

Downstream Receive Power Level : -14.1 dBmV
Downstream SNR : 33.2 dB
Upstream transmit Power Level : 58.0 dBmV

I also notice a little pixelation on both the upstairs and downstairs TV's from time to time, but not all the time.

My setup is: Y splitter downstairs, 1 x V+ box 1 x going upstairs, then a Y splitter up stairs, 1 x Cable Modem (new 255) 1 x Samsung 2110 box.

Thanks

[on in an hour!]

I've noticed my signal levels on my 255 Cable Modem are a little wonky and that I never seem to manage a 20mb connection at any time of the day. What do you think would be the easiest way of getting a Tech out to have a look? I'm not too keen on ringing tech support as they'll blame my PC and tell me the signal levels are fine (or that I shouldn't even know what signal levels are!)

Here they are:

Downstream Receive Power Level : -14.1 dBmV
Downstream SNR : 33.2 dB
Upstream transmit Power Level : 58.0 dBmV

I also notice a little pixelation on both the upstairs and downstairs TV's from time to time, but not all the time.

My setup is: Y splitter downstairs, 1 x V+ box 1 x going upstairs, then a Y splitter up stairs, 1 x Cable Modem (new 255) 1 x Samsung 2110 box.

Thanks
your upstream transmit power level is high mate,at 61dbmv (if it hasnt locked on to the network by then) it will go back to the start and try to lock on again,this is where you would see the rdy light flashing constantly,with the intermittent pixalation it sounds like your boxes could be suffering too.instead of the broadband helpline call normal faults and report the freezing pics,when the tech visits if he has to up the signal levels to improve your picture quality it will then improve signal levels at your modem and you should see a different set of figures than the ones you have above. (an improvement in signal level will REDUCE the upstream transmit power level) good luck.;)

[ollie2001]

Thanks for the reply!

I tried ringing up but after 20mins on hold I gave up...

I've been playing about at home though and have come up with something. I took my modem downstairs and plugged it directly into the feed that comes in from outside and got these readings:

Downstream Receive Power Level : -4.0 dBmV
Downstream SNR : 36.8 dB
Upstream transmit Power Level : 50.0 dBmv

Would I summerize that there's something wrong with one of the 2 splitters? The splitter downstairs looks ancient, it has Qamtex VQ302LC written on it under a Cable and Wireless box, the one upstairs has 3.5db written on each of the outputs, so i'm not sure if that's limiting the signal in anyway? A techs opinion would be appericiated.

---------- Post added at 20:04 ---------- Previous post was at 19:53 ----------

Just quickly adding that I've put the first splitter in and trying off a cable on that and it's gone up to:

Downstream Receive Power Level : -7.9 dBmV
Downstream SNR : 35.9 dB
Upstream transmit Power Level : 53.5 dBmV

Do all splitters effect signal strength so much?

---------- Post added at 20:15 ---------- Previous post was at 20:04 ----------

Right, upstairs before the upstairs splitter, I get this:

Downstream Receive Power Level : -8.9 dBmV
Downstream SNR : 35.7 dB
Upstream transmit Power Level : 54.5 dBmV

I think the upstairs splitter is having the biggest effect, but the downstairs on is still adding 3-4 minus db to the line.

[homealone]

this is a good reference for nominal signal levels

http://www.cableforum.co.uk/board/12/26006-cable-modem-signal-levels.html

Do all splitters effect signal strength so much?

imo it is rather 'how come splitters manage to work with so little drop in signal strength' ;)

[ollie2001]

According to that:

"Downstream Receive Power: Ideally +/- 3dBmV, cause for concern at around +/- 8dBmV, different modems handle the higher and lower levels differently however I'd expect to see service degredation at that point."

So -14 dBmV is wayyyy out...

Is there nothing I can do personally or will a tech have to visit?

[on in an hour!]

According to that:

"Downstream Receive Power: Ideally +/- 3dBmV, cause for concern at around +/- 8dBmV, different modems handle the higher and lower levels differently however I'd expect to see service degredation at that point."

So -14 dBmV is wayyyy out...

Is there nothing I can do personally or will a tech have to visit?
as i said earlier ollie (and youve proved the fault yourself :tu:) your signal levels are too low from the network.splitters are active pieces of equipment.a 2-way splitter has a loss of 3.5db (as youve posted) and you see your transmit power level go up when they are in the configuration.so if a tech can give you an extra say 4db from the network to your house this will compensate for the loss through your splitter and give you the 50dbmv power level you had without the splitter.;)

[ollie2001]

I've sent them a letter today stating the fault, so hopefully it will find it's way to the right person! To be honest, I hate ringing them up.

Thanks for the replies though!