[Question] yellow brick boosters/cable boosters

[dibbers]

OK, just a question or 2 on cable boosters and the yellow brick booster......i need this as the equipment that is running struggles without it....so I'm wondering can vermin check signal levels and that, as the booster is inside the property then the signal level into here will be the same... the booster is working by taking a weak signal and increasing it to the connections.....but once it's inside the house....

So couple of questions...

does it matter to what signal level that i have it set on....
can it be detected that there are a few devices connected..
my current signal is

Receive Power 18.5 dBmV
Signal to Noise ratio 37.1 dB


does this matter?

what about return and that...i take it this yellow brick is just incoming only....

and.......last one, can you buy a cheaper alternatives to the "yellow brick" need another one...so i have 2 running.....

 

[nozzer]

OK, just a question or 2 on cable boosters and the yellow brick booster......i need this as the equipment that is running struggles without it....so I'm wondering can vermin check signal levels and that, as the booster is inside the property then the signal level into here will be the same... the booster is working by taking a weak signal and increasing it to the connections.....but once it's inside the house....

So couple of questions...

does it matter to what signal level that i have it set on....
can it be detected that there are a few devices connected..
my current signal is

Receive Power 18.5 dBmV
Signal to Noise ratio 37.1 dB


does this matter?

what about return and that...i take it this yellow brick is just incoming only....

and.......last one, can you buy a cheaper alternatives to the "yellow brick" need another one...so i have 2 running.....

I think your receive power may actually be too high. Its normally expected to be between +10dBmv and -10dBmv. Your SNR looks about average.

I think you may need an attenuator rather than a booster !

 

[dibbers]

i turned the little dials like a quarter of a turn, and kept going......as everything locks on in an instant....shud i turn them down?

ok what about this...

Receive Power 6.5 dBmV
Signal to Noise ratio 32.2 dB

 

[nozzer]

What are you measuring the levels on ?

Just about every bit of equipment seems to measure a different way. I tend to look at the modem status pages as they are relatively much of a sameness in measuring.

If your measuring on a modem, then look at the signal level when the modem is connected directly to the feed without anything else being connected (no splitters or anything - just straight connect to incomming feed).

If your levels are still higher than 10dBmv then you dont need an amplifier at all. You need to reduce the signal level.

 

[nozzer]

Receive Power 6.5 dBmV
Signal to Noise ratio 32.2 dB

That looks a bit better but i'd reduce them a bit further. Aim to get 0dBmV

 

[dibbers]

i found that if i didn't have the yellow then this set up here was suffering, and then next door the xbox etc etc was not giving me great gameplay, brought the brick into here to run this and was thinking of getting another one for the sitting room for the laptop, boxes, modem, xbox partys.....(some times 3 connected at once, with internet radio and MTV all on)

Receive Power 0.1 dBmV
Signal to Noise ratio 27.4 dB

 

[nozzer]

You shouldn't really need multiple amplifiers and non at all for any modem path !

When connecting, split the main incoming feed. Use one tap to the amplifier and then split the output of the amplifier to any stb's etc.

The other main tap off the incoming feed should be taken directly to your modem(s) without going anywhere near an amplifier.

tbh, multiple modems (if thats what you've got) are more of a pain than anything else. You'd do better using a single modem and a router to split the ethernet signal to your PC's. That should be more than adequate on a 20Meg connection unless your into serious downloading (in which case get yourself 50Meg). Xboxes etc should use only very small amounts of bandwidth for gameplay.

 

[nozzer]

Receive Power 0.1 dBmV
Signal to Noise ratio 27.4 dB

Probably up it a bit !

You need to compromise a bit in that you really want the snr to be over 30 whilst the power is as close to 0 as you can get it whilst maintaining snr.

Your 6.5dBmV may of been a better compromise level.

 

[dibbers]

got the main split at the door......one feed into here, and the other runs to the sitting room....

the modem path i've got split in here with a 3 way splitter (since they brought the "return path" thing out on the splitters they give me rubbish signals.....like -db and that and i can't lock on....


then into the sitting room with another 3 way splitter....


i have a router here that does these 2 pc's (and my wireless network) and then a netgear next door that has it's own feed and that is connected via a switch to these 2 pc's and gives the lap top it's own internet connection and my ME1 (network media player)

best i can get it....

Receive Power 3.5 dBmV
Signal to Noise ratio 30.2 dB

 

[nozzer]

got the main split at the door......one feed into here, and the other runs to the sitting room....

the modem path i've got split in here with a 3 way splitter (since they brought the "return path" thing out on the splitters they give me rubbish signals.....like -db and that and i can't lock on....

then into the sitting room with another 3 way splitter....

Too many splitters and stuff going on here !

I'm reading that as a spliter tap taken to another 3 way splitter and then a tap from that taken to yet another 3 way splitter. Is that correct ?

If thats right then I think you need to do some serious rationalisation of your cabling. You've just got too much going on there !

As I said previously, the modem (assuming you've only got one) should be taken from its own tap at the cable entry point. It should not have any more taps taken from that particular connection.

Other taps can have amplifiers, if necessary, but you should never attempt to use an amplifier on the modem tap as it can seriously affect the return channels. The yellow brick does have return capability BUT it compromises the modems ability to set its own reply level (the modem has its own built in variable amplifier for the return channels). It also adds significant noise to the return (all amplifiers introduce noise).

You mention -dB. Thats normal. Most modems run at about -3dBmV. Mine runs at about -7dBmV without problem. The target is 0dBmV but installers are quite happy to have 5dBmV to -5dBmV on commision. This level will normally decrease as you add splitters.

Receive Power 3.5 dBmV
Signal to Noise ratio 30.2 dB

Thats probably ok. If you have problems then turn the power level up slightly but try not to go above 10dBmV. Its important that the snr stays above 30dB though !

Snr is often made much worse by a large number of cable joins. Thats why its usually better to only have the cable split once. If you need three taps then use a 3 way splitter at the cable entry point rather than cascading splitters.

 

[dibbers]

thanks for that it's intresting to know.....though now i don't think i can do any thing about it....(new carpets and all cables laid) entry point in hall has 2 way splitter so each seperate feed from that 2 way has a 3 way connection on the end of it.....

 

[Bad_Ad84]

He's been told all this before.

 

[dibbers]

llol...man......i can't see how to make my network do the things i do with just a single modem.....


and you never gave me signal levels....ptttt just coz i beat you on the golf

 

[dibbers]

OK I've benn pondering.....lol.....if the signal measured at the splitter (main feed into property) is still it's normal self and i take that signal and boost it through the brick at one of the ends then the signal at the splitter at point of entry is still say reading

Receive Power 0.0 dBmV
Signal to Noise ratio 30.1 dB

and then at the end of that attached to it is the yellow brick, too say a modem and that's reading

Receive Power 5.8 dBmV
Signal to Noise ratio 37.1 dB


then all i'm doing is just increasing the signal indoors.within my home, and the signal still too my property is the norm.....just a question, but why would the yellow brick allow to boost your return path...it's a booster for incoming signal no ?

 

[MFCGMFC]

its to help the modem make a connection on the way out aswell mate but most don't need it

Cheers
MFCGAVMFC

 

[dibbers]

is that the upstream bit then

Upstream
Frequency 22 MHz
Channel ID 2
Status Ready
Mode TDMA
Symbol Rate 2560000 sym/sec
Transmit Power 55.0 dBmV


yeah but all the settings on the yellow are incoming

 

[MFCGMFC]

are yoy getting a better connection with the booster inline?

Cheers
MFCGAVMFC

 

[dibbers]

everything locks on line in a second and dvb- dream etc is instant.....

 

[nozzer]

is that the upstream bit then

Upstream
Frequency 22 MHz
Channel ID 2
Status Ready
Mode TDMA
Symbol Rate 2560000 sym/sec
Transmit Power 55.0 dBmV


yeah but all the settings on the yellow are incoming

At 55dBmV your modem is struggling to be heard !

Thats nearly always a sign that your internal cabling is too complex with too much loss and too much noise being injected. Check your modem power level when its connected directly to the feed. If its over 50dBmV then you have a dodgy feed from VM. Most modems will run at under 45dBmV when connected directly to the feed.

The yellow bricks dont amplify the return signal (or they shouldn't). All they do is provide a return path bypass. The bypass is ALWAYS lossy as its effectively just a simple low pass filter.

Also remember that the return frequencies (10-60Mhz) act very differently to the forward path frequencies (90Mhz - 900Mhz). The forward frequences themselves (because its such a big range) can act very differently. You may find that transponders at 120Mhz seem very much stronger than those at 500Mhz. This is simply down to the characteristics of the cable line and things like cable joints etc.

 

[dibbers]

I'm still not grasping it though....if the yellow brick don't have an active return gain then there isn't nothing to worry about with in the property i'm not sending back 60 db to them etc.......if it's increasing the signal to the modem and the other devices and making them work a treat after boosting the incoming signal then all I'm doing is actually getting false readings, well not false but readings from equipment within here after the signal has been boosted...........so it's not like i am actually getting them from the external feed with massive spikes and stuff ....if you get me......

if i went and read my readings at the main point of entry they'd still be showing me sensible levels....it's just after the booster that the equipment is connected too that's showing massive signal levels increased......but as i say at the main feed i'm still getting the norm ?


hope you understand what I'm thinking...