coxial cable extension Broadband

sshan · 02-07-2009, 19:41

Hi guys,

i recently extended the coaxial calbe from the socket to cable modem (around 3 months ago), at the time i was on the 10MB service, however i upgraded to 20mb service couple of weeks ago and seem to notice some problem with the modem Downstream Frequency and upstream power levels.

Downstream Frequency: 315000000 Hz
Downstream Power Level: 2.8 dBmV
Signal to Noise Ratio: 37.9 dB

Upstream Frequency: 25808000 Hz
Upstream Power Level: 60.5 dBmV

seem to problem with both the down freq and upstream power level, i was under impression that down freq should be around 333000000HZ and powerlevel aunder the 60 dbmv.

i used high quality cables when i did the extension FT100 coax from maplin and also used Gold plated F connectors. the problem is wired coz i never had this problem when i was on the 10MB service only when upped to 20mb service this seem to be a problem?

my cable modem is : Scientific-Altanta WebStar Cable Modem

any help would be greatfull, thanks

on in an hour! · 02-07-2009, 19:54

Quote:

Originally Posted by sshan

Hi guys,

i recently extended the coaxial calbe from the socket to cable modem (around 3 months ago), at the time i was on the 10MB service, however i upgraded to 20mb service couple of weeks ago and seem to notice some problem with the modem Downstream Frequency and upstream power levels.

Downstream Frequency: 315000000 Hz
Downstream Power Level: 2.8 dBmV
Signal to Noise Ratio: 37.9 dB

Upstream Frequency: 25808000 Hz
Upstream Power Level: 60.5 dBmV

seem to problem with both the down freq and upstream power level, i was under impression that down freq should be around 333000000HZ and powerlevel aunder the 60 dbmv.

i used high quality cables when i did the extension FT100 coax from maplin and also used Gold plated F connectors. the problem is wired coz i never had this problem when i was on the 10MB service only when upped to 20mb service this seem to be a problem?

my cable modem is : Scientific-Altanta WebStar Cable Modem

any help would be greatfull, thanks

im ex-ntl but downstream should be between 0 to minus 5 (have worked as far out as -12)
your upstream is right at the limit (highest being 61 then retrying) if your in a 50meg area then as a 20meg user you will be on the new 50meg ubr's which have 4 frequencies (again ex-ntl) im not sure if its the same all over the country though.
that said,ive been to faults where subs have cabled their own extensions for cable tv and broadband and theyve worked fine for weeks/months but the obvious fault was loss of signal from original termination point (by VM engineer) and subs own termination point after extending the cable.

if you call them out and thats the case you will be charged £30 for the service call,if tech cant do the re-cabling there and then its a further £99 to book an appointment for the install partners to return and cable correctly

how about moving everything back to its original point before you moved it and posting all the above info from the original point of install

sshan · 02-07-2009, 20:15

Quote:

Originally Posted by on in an hour!

im ex-ntl but downstream should be between 0 to minus 5 (have worked as far out as -12)
your upstream is right at the limit (highest being 61 then retrying) if your in a 50meg area then as a 20meg user you will be on the new 50meg ubr's which have 4 frequencies (again ex-ntl) im not sure if its the same all over the country though.
that said,ive been to faults where subs have cabled their own extensions for cable tv and broadband and theyve worked fine for weeks/months but the obvious fault was loss of signal from original termination point (by VM engineer) and subs own termination point after extending the cable.

if you call them out and thats the case you will be charged £30 for the service call,if tech cant do the re-cabling there and then its a further £99 to book an appointment for the install partners to return and cable correctly

how about moving everything back to its original point before you moved it and posting all the above info from the original point of install

hi ya thanks for quick reply, sure i think i can move it back to original setup.
i still got the cable the blueyonder tech installed.

here is funny thing i just got off the phone with VM and they goona send a new modem, i dont understand this LOL. but will see.

on in an hour! · 02-07-2009, 20:18

a new modem might not go amiss!! although with you being in TW land i dont know whats a good or whats a bad un to have,but it would be interesting (and potentially saving you money) if you did post your up/downstream levels, and such, back at the original termination point

sshan · 02-07-2009, 20:23

Quote:

Originally Posted by on in an hour!

a new modem might not go amiss!! although with you being in TW land i dont know whats a good or whats a bad un to have,but it would be interesting (and potentially saving you money) if you did post your up/downstream levels, and such, back at the original termination point

by origiral termination point u mean the at the wall socket? or u mean to fit back the original cable to socket and to modem and then take the reading?

on in an hour! · 02-07-2009, 20:24

wherever the VM tech left your modem before you started maulin about!!

sshan · 02-07-2009, 21:10

Hi ya i just reconnect all the original calbes and this is waht i got.

Downstream Frequency: 315000000 Hz
Modulation: 256QAM
Bit Rate: 20480000 bits/sec
Power Level: 4.5 dBmV
Signal to Noise Ratio: 37.9 dB

Upstream Frequency: 25808000 Hz
Modulation: 16QAM
Bit Rate: 768000 bits/sec
Power Level: 59.0 dBmV

upstream power levels seem to have improved but other than that there is no change, also downstream power level went from 2.X to 4.5

fatassmichael · 03-07-2009, 18:51

iirc the scientific atlanta webstar *revision 1* has issues on the 20Mb service, call faults if you have one of these modems, they should send you out an ambit 256 modem.

broadbandking · 03-07-2009, 19:00

I have never seen a issue with the webstar modems, the downstream is fine the upstream is getting rather high, let us know how the new modem gets ion.

sshan · 03-07-2009, 19:29

hi all thanks for the repley

just got the new modem installed all seems ok now

here is reading from the new modem

Downstream Frequency: 331000000 Hz
Modulation: QAM256
Bit Rate: 20480000 bits/sec
Power Level: 2.3 dBmV
Signal to Noise Ratio: 38.1 dB

Upstream Frequency: 29200000 Hz
Modulation: QAM16
Bit Rate: 768000 bits/sec
Power Level: 53.5 dBmV

everthink seem to have improved. both down and up frequency went up, also now the power level is less than 55dbmv

hopefully it all ok now

thank you for all your help

sshan · 04-07-2009, 16:04

hi ya quicky question, if my downstream power level goes to:

Downstream Receive Power Level : 0.8 - 1.0 dBmV

is that ok

i am on Telewest/blueyonder network, plus my area has the 50Mbit now.

is it ok as long it is with in 0 - 5 dbmv ?

Ignitionnet · 04-07-2009, 17:40

Bad news is that you may find the issue reoccurs if your downstream frequency goes back to one of the others - we'll see.