Problem Connecting Satellite Dish to Home Cables

fatlog

Hi,

I'm a complete noob on all this so apologies!

Little background first...

I moved into a new house last year and we had it refurbished top to bottom. New electrics etc... Each room was wired for a phone and TV. The TV cables "appear" to be co-axial. They have a copper core, white sleeve, copper-ish coating around the white sleeve and a black outer sleeve. All the cables run from each room to the attic. All fairly bog-standard (i think).

We got connected to UPC and this works fine. No issues at all.

I picked up a cheap satellite dish recently with the intention of hooking up each room. It has a single LNB and I know i need a quad LNB for 4 rooms etc... At the moment i just want to get one room up and running.

I ran a co-axial cable from the dish to the house and into the attic. I connected a TV to it in the attic to make sure it works. I was able to tune in channels fine. The dish isn't perfectly aligned but is fine. I tried connecting the bedroom cable (i know its the correct cable for bedroom) to the dish cable and...nothing -> "Bad or No Signal" is message from STB. I tried connecting each of the other room cables and went around with the box to each room and nothing. I even disconnected the NTL cable(which i know works) and connected the dish to it and still nothing. I ended up geting another length of co-axial cable, drilling a hole in the bedroom roof and feeding it down. Obviously not the best solution but will do for the moment.

So, my problem is that none of the cables installed in the house seem to be able to carry the signal from the dish. Is this possible? I thought/presumed that co-axial is co-axial. Am i missing something silly here??

Any help would be greatly appreciated

AstralTV

try removing the UPC diplexers or wall plates & connect directly to the ends of the cables in each room,

aerialbits

Hi. There is a big differance in the performance of coax and components which will effect whether something will work or not.

Most coaxial cable placed in a house is done so by the electricians. Electricians have plenty of training on their core work but they only touch communications and the wiring involved with it in a very basic way.

So when they are laying this cable they firstly obtain the cheapest chinese garbage that can be found, after all they are after the cheapest option they don't have the technical knowledge to understand the technical issues.


Cable may not have enough screening to prevent ingress of unwanted signals and egress of the wanted signal to interfere with other communicaiton items. (fridge freezer motor kicks in blocking and freezing seen on tv picture, has any of you noticed that)

cable braiding may not be enough to provide a good earth or the connectors you have may have too large or too narrow a diameter to make a proper connection. There are alsorts of connection issues that if people where aware of would make their lives much simpler when dealing with this stuff.

You need to get a good quality coax. You don't have to buy the ct100 which the bull****ters flog as the best available. A good quality well screened well braided coax will do. It is absolutely ESSENTIAL. That you waterproof the connection properly at the LNB on the dish. If you don't through time water will eventially get in and will travel down the coax to write off you satellite box.

They then proceed more often than not to wire the houses in such a way that improper connections are made, they butt joint, loop cables from one position to another etc etc.

If they do wire it correctly there is usually not enough at specific points to fully cable up (2 cables for sky plus + 1 for an aerial + 1 to distribute back to other tv points in the house "complicated")

The wall plates that are used may pass power or they may not. Meaning that if a recieve is connected to the wall socket the power it sends up the cable at the lnb may be stopped at the wall socket.

I am a city and guilds trainer for Satellite and Aerial Systems. Sparks and House designers/Architect would need a couple of days training to be able to do what they need for the end customer. But In Ireland the Designers are arrogent and won't do the training. The sparks in my view don't give a toss about the end user they are just after their money and won't do the training either. They they wonder why the Poles who are trained properly in their own country take what work there is.

fatlog

AstralTV wrote: »

try removing the UPC diplexers or wall plates & connect directly to the ends of the cables in each room,

tried that i think.
do you mean remove wall plates and use co-axial wire directly? if so then i did that.

thanks

fatlog

thanks for all the feedback so far.

regarding the quality of the cables. i've no doubt the guys that re-wired the house probably used the cheapest cable available. what i dont get though is that my UPC connection is using one of these wires and is working fine. there are no noticeable quality issues with the reception i am getting from my UPC channels. would this be because the signal strength form UPC is so strong?

also, i previously split off my UPC connection in the attic to feed the analogue channels to each of the other rooms and this worked fine, albeit the picture quality wasn't the best. I still was able to get the analogue channels tuned in however.

one other thing. i dont know the irght terminology here. The connectors that UPC put on the cables have "Cable Conv 3.9" on them. Is there any significance in that? or is the 3.9 just the diameter of the cable core or something like that?

thanks again

Apogee

fatlog wrote: »

thanks for all the feedback so far.

regarding the quality of the cables. i've no doubt the guys that re-wired the house probably used the cheapest cable available. what i dont get though is that my UPC connection is using one of these wires and is working fine. there are no noticeable quality issues with the reception i am getting from my UPC channels. would this be because the signal strength form UPC is so strong?

It's because the satellite signals are at higher frequencies (approx 900-2100MHz) versus the UPC signals (around 300-700MHz). The higher the frequency, the greater the loss over a given length of cable. Any joins/splits in the cable will also cause problems.

also, i previously split off my UPC connection in the attic to feed the analogue channels to each of the other rooms and this worked fine, albeit the picture quality wasn't the best. I still was able to get the analogue channels tuned in however.

If you intend having multiple satellite receivers in different rooms running off the quad LNBF, then you cannot use split cables. Each receiver will require its own, separate cable running to the LNBF port - the reason being that each receiver is sending both power and different switching signals back to the LNBF.

Liameter

aerialbits wrote: »

You don't have to buy the ct100 which the bull****ters flog as the best available.

You are a few years out of date. CT100 hasn't been manufactured since 2005 when Raydex was bought out. The current equivalents are WF100 and TX100. There are other (mostly Chinese) equivalents that are just as good but choose carefully because some are not. If it seems cheap, there's a reason. Copper is VERY expensive these days, so one way to make cable cheaper is to use less copper - which means poorer conductivity and maybe poorer screening.

(Aluminium foil cable is OK for short runs indoors but tends to deteriorate fairly quickly outdoors in a damp climate.)

fatlog

so would i be right in saying that the problem is most likely the quality of the cables in the house?

is there anyway around this other than replacing the cables? i.e. can the signal be boosted in some way?

Liameter

Not so much "quality" as simply the *wrong* type of cable. As you say, it works OK for UPC. There's a faint possibility that you could force more signal through by fitting an "equalised gain slope" LNB amplifier to the end nearest the dish. This is a bodge but probably easy to try. Certainly easier than installing the proper cable.

JaneAusten

Liameter wrote: »

Certainly easier than installing the proper cable.

Not necessarily... If there is sufficient room in your conduit you may be able to hook a length of 'good' coax onto the end of the coax at the wall plate and pull the new cable through from above to replace the old one - just don't lose it half-way up!

heffo500

I use this cable anyone got an opinion on it.

Triax RG6/U 250m Black Coax Satellite Cable - Wooden Reel

Conductor CCS Dia 1.02
Insulation FPE Dia 4.6

First shielding mm AL/P-Foil

First Braiding Al Wire Braid
Conductor Dia 0.120
Conductor Qty. 64
Coverage 46%
Lay Lenght 40

Jacket PVC
Outer Dia 6.5 BLACK

Electric Characteristics
Impedance 75ohm
Capacitance 52pF/m
Velocity ratio 82%

DCR conductor < 102ohm/km
DCR Shielding < 60 ohm/km
Return Loss 5-1000Mhz >23
1000-2200Mhz >18
Attenuation at 20C (dB/100m)

5 1.6
50 4.6
100 6.5
200 9.5
460 15.00
860 19.5
1000 21.5
1750 29.00
2150 32.5
2200 33.00
3000 29.00