Poor Signal

[MorriSoft]

Originally Posted by thedigger

Cheers!

The cables I have are all either properly crimped by VM installers or pre-moulded ones from Maplins. I really hope the original VM ones aren't faulty, as they're mostly hidden under floorboards, and there would be a lot of lifting carpet / laminate floors / skirtings and floorboards if it was damaged.

Btw, it could also be a damaged attenuator in the wall box... just noticed that if I wiggle the cable at the bottom of this, the signal dies completely

Sounds like either;

a) as you suggested, dead/dying attenuator
or
b) cabling issue, this is further re-enforced by your statement above, wiggling the cable itself shouldn't cause signal loss at all.

I recommend trying the setup without the attentuator connected first, should that make no difference, you could try cables next - worked for a friend in the same boat as you're in now (cables not easily accessed).

Cables: Remove the ends from any of your cables that look even remotely loose and replace them with new connectors. I recommend screw-on type F-connectors as they require very little effort to put on the cable ends yet prove to be pretty tough to remove afterward (a good thing really, no likeliness that they will become lose over time, unlike crimped cables)

[thedigger]

Thanks again, will try that when I get in tonight

Expect some expletives if I have to lift the floorboards

[MorriSoft]

Originally Posted by thedigger

Thanks again, will try that when I get in tonight

Expect some expletives if I have to lift the floorboards

Heh, well, I hope we can resolve your problem without needing to go to such an extent, but only going to find out as we go.

If you get massively stuck, I'm available this evening for help by email/msn. Get in touch - administrator (at) morrisoft (dot) co (dot) cc

[thedigger]

Thanks again, hopefully it won't come to that, but I'll give you a shout if I'm stuck

[thedigger]

Hi again... Morrisoft, didn't want to bother you directly as it's not a huuuuge fault, but I have:

Removed the attenuator (0.6db btw) and replaced with a splitter.
Cabled V+ box to "cable out" on SV.

Initially, I got no BB, no TV on either box. After a long wait for broadband to come on and rebooting both TV, I now get broadband, SV, and V+ - although the "Online" light is flashing on the V+ box and all interactive features are not available.

These are the readings from my cable modem:

Downstream Receive Power Level : 0.4 dBmV (fluctuates between .2 and .6)
Downstream SNR : 39.5 dB (hovers around 40.0dB)
Upstream transmit Power Level : 47.5 dBmV (rock solid)

From SV, I get:
Level - approx 80%
Quality - approx 80%
(both fluctuate wildly, between 70% - 95%)

V+ has:

SNR: 33.0, 31.0, 32.0dB
AGC Signal Level: -4, -9, -5 dBmV

Are these values normal? I'm no expert when it comes to measuring signal strengths

[MorriSoft]

Originally Posted by thedigger

Hi again... Morrisoft, didn't want to bother you directly as it's not a huuuuge fault, but I have:

Removed the attenuator (0.6db btw) and replaced with a splitter.
Cabled V+ box to "cable out" on SV.

Initially, I got no BB, no TV on either box. After a long wait for broadband to come on and rebooting both TV, I now get broadband, SV, and V+ - although the "Online" light is flashing on the V+ box and all interactive features are not available.

These are the readings from my cable modem:

Downstream Receive Power Level : 0.4 dBmV (fluctuates between .2 and .6)
Downstream SNR : 39.5 dB (hovers around 40.0dB)
Upstream transmit Power Level : 47.5 dBmV (rock solid)

From SV, I get:
Level - approx 80%
Quality - approx 80%
(both fluctuate wildly, between 70% - 95%)

V+ has:

SNR: 33.0, 31.0, 32.0dB
AGC Signal Level: -4, -9, -5 dBmV

Are these values normal? I'm no expert when it comes to measuring signal strengths

The levels and SNR values appear to be 'typical' and thus it seems odd, the level and quality of your signal though, especially fluctuating as you mentioned.

Anything below 75% can cause breakup, that said, anything above 90% strength could also cause breakup.

Signal levels are important, be it too high or too low, both are as bad as the other.

You mentioned removing the attenuator, and although the V+ interactive services are not fully functional, you can watch TV with it I assume?

Also while on the net, does the modem drop out alot? Or is it very slow?

If you have replaced all the loose cable plugs in your setup, you could next try replacing any splitters. If that does not help you problem though, I think it's likely we will either need a booster if it turns out the signal levels are too low or perhaps a variable attentuator, should it turn out to be too high.

Edit: When checking signal levels on my Eurovox ex7000 I noticed that the level and quality meters were slightly jumpy giving odd readings every so often, then immediately reverting back to the true figure (absolutely NO picture issues, or channel loss though), perhaps your box is doing the same thing and being slightly too sensitive on the tuner side, picking things (signal/quality levels) up wrongly too.

[thedigger]

Thanks again for the informative reply MorriSoft

"You mentioned removing the attenuator, and although the V+ interactive services are not fully functional, you can watch TV with it I assume?"

Yep, TV works on all three tuners (recorded two programmes, watched another, no noticeable breakup - all were SD channels if that makes a difference... I guess they use far lower bandwidth than HD)

As for the SV readings... they were generally around 80%, but in the 20 seconds or so I had the signal level readings on the screen for, they bottomed out around 70% and maxed our around 95%.... most of the time they fluctuated between 77 - 84 or so.

Hmm.. I'm in two minds now. I have XL on the V+ so there aren't many channels I miss out on (haven't watched a movie in months, decent sport is only on about once or twice a week, and the porn, literally, ain't worth a w**k ). So, I'd consider sticking the SV in a cupboard until I need it... unless the cost of a booster was reasonable? Do you have any recommendations?

[MorriSoft]

Originally Posted by thedigger

Thanks again for the informative reply MorriSoft

"You mentioned removing the attenuator, and although the V+ interactive services are not fully functional, you can watch TV with it I assume?"

Yep, TV works on all three tuners (recorded two programmes, watched another, no noticeable breakup - all were SD channels if that makes a difference... I guess they use far lower bandwidth than HD)

As for the SV readings... they were generally around 80%, but in the 20 seconds or so I had the signal level readings on the screen for, they bottomed out around 70% and maxed our around 95%.... most of the time they fluctuated between 77 - 84 or so.

Hmm.. I'm in two minds now. I have XL on the V+ so there aren't many channels I miss out on (haven't watched a movie in months, decent sport is only on about once or twice a week, and the porn, literally, ain't worth a w**k ). So, I'd consider sticking the SV in a cupboard until I need it... unless the cost of a booster was reasonable? Do you have any recommendations?

Boosters vary in performance and price. The best I've found that works with modems too is the Konig PRO30 CATV Amp, its a yellow brick shaped booster with active return path, and thus your modem can get online whereas some boosters do no have a return path making the use of a modem impossible with such a booster.

The signal levels appear to be fine especially after you mentioned the SV sits well within reasonable levels most of the time.

Try your setup with as little cable joins as possible, and remove the splitter from where the attenuator was and replace it with an f-joiner for male-male f-plugs (a pain I know but splitters literally half the signal, and that could be the cause of your lost interactive services)

[thedigger]

Excellent!

I'll get an F-joiner next time I go past a Maplins.... Mrs will have to do without Eastenders on TV on demand for a few days (why she doesn't just add it to V+ is beyond me )

[thedigger]

Argh, it gets worse

I've had really bad picture quality on my TVs other inputs (like the PS3) for the last few days. Googled a bit further, and found it's an ground loop.

So yeah, guess where the "bad" earth is coming from.... the cable line. I put the 0.6db attenuator back in, and the picture quality is perfect. And yes, not enough signal to drive both boxes.

Driving myself nuts with this, lol.