Signal strength - What can I do?

Hi,

Last week I posted that I had a pretty ropey BBC 1 on my Dreambox. All 10+ versions of it would suffer lots of breakup.

I had assumed the problem was a weak signal, but after messing today it seems the problem is BBC 1 is far too strong.

With an attenuator of 12db on my cable I now get a perfect BBC 1!

Sadly all is not well. Taking the signal down so much means a number of other channels that were perfect now break up!

Is there anything I can do?

At 8db BBC 1 breaks up a lot, and I haven't got anything to try between 8 and 12 yet to see if there is a trade off that works for all channels.

Cheers
Marc

What frequency is BBC1 on? as a cable equaliser or cable simulator may solve this problem.

Frenchman

frenchman said:

What frequency is BBC1 on? as a cable equaliser or cable simulator may solve this problem.

Frenchman

Click to expand...

Okay, that only leads to 3 questions....!

How can I tell you what frequency BBC 1 is on? It is on eveyr version of the Beeb I've tried.

What is a cable equaliser?

What is a cable simulator?

Now I feel stupid!

If you are using UK04 goto BBC1 press red then blue on the left had side of the screen it will tell you what frequency it is on, it is more than likely that it is on a low frequency and you will need an equaliser which attenuates the signal at the lower freq and not the higher freq giving you a flat signal.

The cable simulator works the other way around.

Frenchman

This is what it says for frequency:

Freq: 458.750 MHz (v)

Just looked at my connections. There is probably a good case of me not having a clue what I'm takling about.

I have used a splitter and am using the output labelled 3.5db (can use a 7db one if necessary). What I thought was an attenuator is actually labled 8db forward path equaliser.

With those two I get 90% channels ok.

With the 8db equaliser on the 7db splitter output lots of channels are bad.

With just the 8db equaliser on the unsplit output (or nothing on it) I get all channels fine except for BBC 1 which is bad, and BBC 2 which is ok.

Suggestions please!

Take out the forward path equaliser and connet direct to the 7db port, see what that does.

Frenchman

Just goes back to being a bad BBC 1 and all other channels seem ok.

got this off another forum

recently a lot of areas have got reduced power on fta channels
bbc1 used to be the best signal going but not anymore

so this could be your prob

also be careful with attenuators a 3db will half your signal using a 6db you will only get a quarter so a 12 db will leave you with an eighth

whistling said:

got this off another forum

recently a lot of areas have got reduced power on fta channels
bbc1 used to be the best signal going but not anymore

so this could be your prob

also be careful with attenuators a 3db will half your signal using a 6db you will only get a quarter so a 12 db will leave you with an eighth

Click to expand...

But what I don't understand is with a splitter at 3.5db or 7db and a 8db equaliser I get perfect BBC 1 with what must be a lower signal than not using anything on my feed.

Do need to sort this out as the box just can't be a living room box until I do!

you can suffer from too strong a signal so thats when attenuators are useful, if your signal is strong use a small attenuator at first until you get the correct balance, also fta channels work better on some images than others dont no why

whistling said:

you can suffer from too strong a signal so thats when attenuators are useful, if your signal is strong use a small attenuator at first until you get the correct balance, also fta channels work better on some images than others dont no why t

Click to expand...

UK04b seems a little better, but it is still a problem.

tbh ive come across loads of threads like this, the one thing that struck me weather dbox or dreambox there doesn't seem to be a reliable method of testing signal strength all it shows is that its crap does not say weather too strong or too week. seen a so called low signal put a attenuator on gets a stronger signal [work that out] so i would not take much notice of what box says .they say check signal at modem, not tried that meself yet

Right now I seem to have got to an acceptable point!

I don't understand it, but hey it works!

So with UK04b I have the following:

The 8db equaliser on the feed from the wall.

This goes into a splitter.

Now using the 3.5db output (which I assume is the same as using an attenuator) I seem to get a stable BBC 1 and the channels which dropped out before in the config (in UK04) and worked fine with no attenuators/equalisers now all seem fine too.

Now if I run 20m of cable off that will it still work in the lounge?!

thats what im saying if there was a reliable method of testing signal strength you could have sorted this hours ago, but hey your getting there lol