Signal degredation

[bogart99]

Hope this is the correct forum to post this topic.
My setup is a sat signal and a terrestrial signal combined then fed down a single downlead to near to the tv. The signal is then split, one leg going to the tv (digital tuner) the other via 10m of coax to a screened diplexed wall outlet. Only the sat signal is used the tv outlet at the diplexer having no connection. The signal to the tv is fine no break ups when the sat equipment is switched off. If powered up the tv signal degrades to the point that certain channels report no signal.
I find this odd as the tv signal is not being utilsed at the end of the 10m run, if another set was connected and switched on I could understand it occuring in that situation. I wondered if, haven't tried yet, I should replace the splitter near the tv with a decombiner and see if that helps. It doesnt seem to worry the tv that its getting a sat signal as well or is it?

Regards

 

[RB2004]

Hi, could you clarify this?

"The signal is then split, one leg going to the tv (digital tuner) the other via 10m of coax to a screened diplexed wall outlet."

Thanks, As both TV and sat should both be connected to a diplexed plate.

 

[RB2004]

Hi, if i have enterpreted this correct, you have diplexed signal (TV and Sat) going down a single downlead to a splitter, one output goes direct to the tv, and the other goes to a diplexed plate where you have sat connected.

This will not work properly, you need to eigther do away with the splitter and replace it with the Diplexed plate, so the download is connected to a diplexed plate, with sat and tv, then have the tv output going to the tv, then the sat output going to sat using an extra long fly lead for your sat, or buy another diplexed plate, so you have one on both outputs from the splitter, then connect the TV into the plate.

The reason you need to have a diplexed plate on the end is to split the 2 signals, if not split they can interfere with eachother.

 

[bogart99]

Was thinking as much. As I need the terrestrial feed at both points, at tv and at 10m away I will add a diplexer to the feed to the tv to block the sat signals and try again.

Cheers

 

[RB2004]

yea if you add another diplexed plate on the TV feed it should solve your problem

 

[bogart99]

Have just replaced the splitter with a decombiner and guess what? no difference. So have done more investigation. At the end of the 10m length as stated before is a decombiner feeding two satellite receivers, not one as before mentioned. I have a technomate with the if out connected into the if in on an amstrad skybox. As soon as the amstrad is connected up the problem occurs. Feeding straight from the coaxial, ignoring the second decombiner, to the technomate everything is fine. Replace it with the amstrad alone, technomate not connected, and the problem returns, even with the box in standby.Odd thing is it doesnt affect every tv channel just the weaker ones. QVC is fine until the amstrad coax is connected it the drops to no signal, whereas BBC is ok at all times. Am really stumped, any more ideas

 

[RB2004]

do you have 2 recievers connected to a single satelite dish?.. if so this requires an LNB with 2 outputs rather than 1

 

[RB2004]

I dont 100% completely understand your setup.

Could you explain the setup in more detail please?

I understand your setup was,

a dixplexed download, with Sat and TV signals, going to a splitter, where 1 output went to a diplexed plate feeding a sat box, and the other output went to a tv without a diplexer plate.

Now your setup consists of, a diplexed download, with sat and Tv signals, going to a diplexed plate, which has 2 sat boxes connected to it?

 

[bogart99]

Sorry does sound complicated. As they say I will start at the beginning.
For the time being forget the Amstrad skybox.

System was as follows.

Standard 90cm sat dish and terrestrial aerial combined in loft. Single downfeed into living room. Signal was decombined at wall outlet. TV signal to tv via STB and sat signal to Technomate sat receiver. Everything worked fine.
TV replaced by Panny LCD with built in digi tuner so STB redundant.

Combined signal then split,not decombined, one leg to Panny directly, other to Technomate sat receiver. No problems eveything fine.

The freeview signal here can occasionally on the weakest MUX be a tad poor so decided to buy a secondhand Sky digibox for FTA and FTV channels. As stated before looped IF output from Technomate to IF input on Amstrad box, as yet no skydish in the equation.
Everything ok able to view outputs from TV, Technomate and Amstrad box, obviously Amstrad just saying no satellite detected. But now if the Amstrad is in standby or switched on the tv signal degrades to such an extent that certain channels, ie weakest MUX, tv shows "No Signal".Switching off the Amstrad box puts everything back to normal.

The intention was/is to combine both satellite signals (after installation of skydish) in loft then again combine with tv signal before again using single downlead.

The problem is not crucial because if I am watching freeview I can switch the Amstrad box off, or if either of the satellite boxes are being watched it doesn't matter that the tv sees a poor freeview signal, I just find it rather odd that the Amstrad box causes this problem, if it didnt life would be a tad simpler.
If you understood the above can you let me know as Im not sure I did.

 

[RB2004]

i think i understand lol, the tv signal goes into one sat box, then out into your amstrad box, before connecting to tv?

im not sure what the problem could be exactly, does the same problem happen with this setup,

downlead into amstrad box, then into tv without other sat box?

if this still does not work it rules out a problem with "daisy chaining", what i mean by this is connecting the tv cable into one box, then out into another box, which connects to the tv.

in which case it is something clearly to do with the amstrad box, you may be able to get more advice about the amstrad sat box in the satelite forums.

 

[bogart99]

Agreed with problem revolving around Amstrad box, will post a message on that forum.

Cheers