Connect Satellite feed and lose RF

[terryk]

Recently re-wired part of the house and brought the incoming satellite feed and the downlead RF feed to a single gang faceplate with a BNC screw terminal for the satellite and the usual coax for the RF.

As soon as I connect the feed from the dish the picture on the RF gets very snowy.

I've checked there are no stray strands inside the faceplate making a connection between the two "ports".

The cables are co-routed for part of their run, could there be some sort of crosstalk problem - or could it be a faulty faceplate.

Any ideas anyone?

 

[RF Lighting]

Are the outputs isolated from each other in the face plate, or do they share a common ground connection?

 

[Lectrician]

I am guessing you didn't use a CT100 or equiv cable, and ran the RF and SKY adjacent?

BAD idea!

You must use fully screened CT100, PH100, DT100, QC100 etc etc etc

 

[terryk]

You must use fully screened CT100, PH100, DT100, QC100 etc etc etc

Drum is marked MICROMARK MM5036 - can't see on a google search whether that fits any of the above.

 

[Lectrician]

When you strip it back, you have a copper braid (lots of copper interlinked strands). Does it also have a copper foil underneath? If it has no foil, it is standard UHF coax. If it has an aluminium foil, it is old school analouge satalite coax, but if it has a copper foil, it is indeed a 100 variant.

 

[terryk]

Are the outputs isolated from each other in the face plate, or do they share a common ground connection?

Not 100 percent sure I understand the question. The two leads are separate inside the face plate - in that the braid and central conductor have their own terminals.

Are you asking if despite having separate terminals the braid is connected via a circuit board? I'll need to upset the Sunday family viewing and take the faceplate off to find out.

 

[Lectrician]

It is likely to share a common ground, as it should, unless the faceplate is made up from euro modules..

 

[terryk]

When you strip it back, you have a copper braid (lots of copper interlinked strands). Does it also have a copper foil underneath? If it has no foil, it is standard UHF coax. If it has an aluminium foil, it is old school analouge satalite coax, but if it has a copper foil, it is indeed a 100 variant.

Aluminium

 

[Lectrician]

Umm - that is not great, but is unlikely to produce the effects you mention.

Describe exactly what you have done/installed.

Also, take a ganders over at www.satcure.co.uk - click their forum link.

 

[terryk]

Umm - that is not great, but is unlikely to produce the effects you mention.

Describe exactly what you have done/installed.

Also, take a ganders over at www.satcure.co.uk - click their forum link.

Needed to extend the Sky cable so in the loft jointed it via two screw BNC terminals and then ran it back to the lounge and terminated it via the aforementioned face plate. RF Cable already reached so just terminated that on the new plate.

RF signal became "snowy" as soon as the Sky cable was connected. Sky signal was a little prone to break-up so put an in-line booster at the BNC joint in the loft and the Sky signal is now rock solid - but it made the RF picture even worse.

 

[dannyboi2003]

[/quote]RF signal became "snowy" as soon as the Sky cable was connected. Sky signal was a little prone to break-up so put an in-line booster at the BNC joint in the loft and the Sky signal is now rock solid - but it made the RF picture even worse.[/quote]

If you have put a signal booster in-between your sky box and your sky dish then you shouldn't have any sky at all. The set-top box feeds power to the LNB (the thing on the dish) via the sky cable, putting a booster on the cable would remove the power supply and kill the sky signal, it may even destroy the booster. This makes me think you have actually put it on the RF cable and not the sky one.

Can you post some pictures of your connections in the loft including the booster and on the back of the faceplate in the lounge. These will help us see better whats been done and where the problem may be.

 

[Lectrician]

You can get boosters for dish feed, but they are rarely seen, and rarely needed!

 

[terryk]

You can get boosters for dish feed, but they are rarely seen, and rarely needed!

I can confirm this is an in line booster designed for a dish feed. It takes its power from the box. Before installing it we had reasonable signal quality but occasionally the signal strength dropped sufficiently for the picture and or sound to break up. Since installing it the signal strength is near the top of the scale and we have had no break ups.

The problem with the RF was there before we put the booster in - although the quality did get worse after its installation - so it is not the cause as such.

 

[nozspark]

I have had this exact problem at home and found it to be a common ground as already said. What I had to do was to cut the track on the PCB, in the socket plate, that joins the screen's together.