100M Signal Levels - Page 3

jb66 · 09-09-2011, 17:11

so thats after loosing 4db on a 2 way splitter and 6db on a 3 way. if you got an HDU to replace both splitters they'd be sitting at a healthy 4db downstream and 41 upstream

RB2004 · 09-09-2011, 18:02

Quote:

Originally Posted by jb66

so thats after loosing 4db on a 2 way splitter and 6db on a 3 way. if you got an HDU to replace both splitters they'd be sitting at a healthy 4db downstream and 41 upstream

yep, but the engineer just kept insisting the signal levels are fine, and that its only -7.1 he would expect problems.

made it clear he wasnt going to do anything... I mentioned i was under the impression nearest to 0 is best and he just made a remark bless their cotton socks and laughed.

said he wouldnt be supplying a HDU, and left.

now, because ive had 2 engineers down who wont do anything.. previously 100mbit support was agreeing with me -6 was borderline and sending engineers.. but now they are just saying there are no problems, and they arent inclined to argue with the engineers oppinion and left it at that.

Thats why now im fed up with bothering with them, and more inclined to do something about it myself.

besides an RG11 repull, and HDU nothing more an engineer can do, as im the only person on the tap, and im already probably on the highest tap.

the setup is, im connected to a tap inside a pit about 4/5 houses away down the road.
then that tap pit is connected to a tap cabinet accross the road about the same distance again.

which is why already i have a bit of a weaker signal, because im connected to a pit and not a cabinet... normally id guess the signal would be fine, but its the amount of devices I have, and the 2 splitters which are causing me to loose 10 dB.

So, if they arent going to give me an RG11, and I cant be moved up on the tap, only solution left is to source a HDU myself, and remove 1 of those splitters. Which should then like you say give me a healthy signal...ive wasted my time calling them up complaining and getting engineers down who seem to be useless.

RB2004 · 10-09-2011, 14:09

My signals appear to be getting worse...

Downstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM256 194 55616000 Kbits/sec 299000000 Hz -6.7 dBmV 38.4 dB Hybrid
Locked QAM256 193 55616000 Kbits/sec 291000000 Hz -6.5 dBmV 38.1 dB Hybrid
Locked QAM256 195 55616000 Kbits/sec 307000000 Hz -6.5 dBmV 38.7 dB Hybrid
Locked QAM256 196 55616000 Kbits/sec 315000000 Hz -6.8 dBmV 38.2 dB Hybrid

Sephiroth · 10-09-2011, 15:51

A few posts back you said the engineer fiddled at the tap. Which tap? The one in the cabinet or the one in the pit?

If it wasn't the pit, he wouldn't have noticed whether or not the pit was flooded.

jb66 · 10-09-2011, 15:53

If you have pits then only a network engineer would go into the cabs

RB2004 · 10-09-2011, 16:15

Quote:

Originally Posted by Sephiroth

A few posts back you said the engineer fiddled at the tap. Which tap? The one in the cabinet or the one in the pit?

If it wasn't the pit, he wouldn't have noticed whether or not the pit was flooded.

Im pretty sure it was the pit, and I know that pit is fed by a cabinet, because there is a cabinet directly in line with the pit accross the road. So my guess is the cables come from the cabinet, underneath the road to the pit, where it is split off to the row of houses where I am.

1st engineer moved my line onto a different tap, because my services cut out briefly.

Then told me there was corrosion where a previous engineer had not sealed it up properly or something, and that he would get networks onto it and left.

So presumably after over a week that work should of been done if it needed doing, then last engineer also said he would get networks to take a look because he said my erratic speeds werent due to my poor signal levels.. and told me they normally come out within 4 hours so presumebly they had a look at the taps or cabinet also.. but didnt knock on my door.

But last engineer said I was the only person on the tap, and presumebly I am already on the highest tap.

However, my signal levels appear to be fluctuating, as before it was around 5.8 -6.1 But todays check shows 6.8 dBmV

I dont believe im going to get any further with VM, getting engineers out or arguing this out over the phone unless my services stop working, as ive tried retentions, CEO office, 100mbit team etc already.

So im going to stick to my plan to try and do anything I can to resolve this myself, i.e removing 1 of the splitters etc to give me a better signal.

Ignitionnet · 10-09-2011, 17:10

Fluctuation is normal and power levels will drop as weather cools

I'd say to hell with this and get your own HDU if you cannot get alternative services.

RB2004 · 10-09-2011, 17:23

Quote:

Originally Posted by Ignitionnet

Fluctuation is normal and power levels will drop as weather cools

I'd say to hell with this and get your own HDU if you cannot get alternative services.

Hi, yep that is my plan.

im going to remove one of the splitters, and change the the 3 way splitter in the brown box for a 4 way.. and give the modem its own feed.

then if i can get hold of a HDU use that instead of the 4 way splitter.

ive got the snap and seal connectors, EX6 which are exactly the same as what VM use, and the tool so they wont know anything has been touched by me.

I know its against the terms of service, but as long as I dont cause any problems.. which I shouldnt anyway then they wont be none the wiser.. just rediculas that its got to a point where I am having to correct this situation myself.

Ignitionnet · 10-09-2011, 17:31

Stuff the terms of service.

Just make sure that the HDU is passive return ideally, or at very least has a return band of 5-65MHz with a forward band of 85MHz-1000MHz.

Something like this:

http://www.soontai.com/DA10.html

DA10 - 65/8510 5 - 65 MHz by-pass 85 - 1000 MHz 10 dB

Those kinda specs would be ideal.

RB2004 · 10-09-2011, 17:34

Hi, Thanks I will have a look for one of them.

I was looking for one of these,

http://62.177.155.228/Portals/4/Down...DU-AppNote.pdf

FDU-61

which I believe is what VM actually use, it doesnt actually amplify the signal though, it just has no signal loss unlike a splitter... so if like me im probably loosing about 10dB with the 2 splitters, by using one of those it would give me the same level signal going into the unit on any of the outputs.

just been unable to find somewhere selling them lol, from what I can gather somebody used to sell them on eBay but i cant find any now.

So probably only obtainable via a VM engineer.

jb66 · 10-09-2011, 18:03

Just keep calling up when you get an issue. I'd have installed one if I was in your area

Sephiroth · 10-09-2011, 18:17

Quote:

Originally Posted by Ignitionnet

Fluctuation is normal and power levels will drop as weather cools

I'd say to hell with this and get your own HDU if you cannot get alternative services.

Not the downstream, Igni. The downstream power levels will rise in winter.

Ignitionnet · 10-09-2011, 18:25

Quote:

Originally Posted by Sephiroth

Not the downstream, Igni. The downstream power levels will rise in winter.

Connectors in common with other metals shrink, less tight contact, offsets the loss of resistance from the cooling.

Will be some cases where this doesn't happen due to in-line amplifiers which respond to changes in temperature but the general trend should be increase in attenuation or a marginal drop at best - between zero and 30C you're talking 0.1dBmV per 30m.

Cable Type Temperature Fahrenheit
P3 500 CA 20 30 40 50 60 70 80 90
Frequency (MHz)
600 1.80 1.82 1.85 1.87 1.89 1.91 1.94 1.96
750 2.04 2.06 2.09 2.11 2.14 2.16 2.19 2.22
1000 2.37 2.41 2.44 2.47 2.50 2.52 2.56 2.59

RB2004 · 10-09-2011, 19:04

Quote:

Originally Posted by jb66

Just keep calling up when you get an issue. I'd have installed one if I was in your area

I know thats what I should be doing.. but to be honest ive lost faith in them resolving it.

every time ive had my services changed, or problems it has always come down to signal problems, i was told i needed RG11 6 years ago, and for all that time ive repeatedly had to have engineers down... who have "claimed" to of fixed it... but now im fed up with it and persisting with this problem and doing my own investigations into it, I find that even though my services are working, my signal levels are borderline which has probably been the issue the whole time, I was just unaware of it.

and so ive had 2 engineers down who have refused to do anything so that will typically be a continuing trend I feel now.

I will see what the signal levels are like after ive removed one of the splitters.. but if it is still not ok, I will try to fit a HDU myself. It shouldnt be anything I cannot do myself, as its only a case of replacing the splitter with it, then running a separate cable to a power supply.

Sephiroth · 10-09-2011, 19:33

Igni, I would expect metal to contract in winter, and if it contracts, it shortens and the attenuation falls; thus the power rises in the downstream direction.

Where have I got this wrong? If it's just due to less tight contact, I would have expected that to be designed out. My own power levels fell in the summer and always rose in the winter by c. 3 dBmv.