Advice needed on a 100m cable run.....

[cdtronix]

Looking at an install on a listed building. Currently they have a sky dish fixed at the bottom of their garden, approx 100m away from the house. sky installed this a year ago and the owner says it have never worked properly and sky have been back and said there is nothing they can do to fix the problem and the owner has now cancelled his contract and wants us to install a dish for digitALB.

there is currenlty 2 cables being fed from the dish going under ground in a tube to the house. Ive checked the signal on the dish and its spot on with quality reading over 90%.

Ive checked the signal level at the box end and on the 2 feeds one gives 0% and the other just gives an LNB short on the meter.

Now, are we looking at an issue with the length of the cable being run to the house

ie is it just too long ?

or is it likely that the cables are damaged somewhere ?

What options is there to get a decent signal at the house, the owner is addement that the dish must stay where it is and doesnt want it closer to the house as the building is listed. Would an amplifier help in any way ?

Be intrested in some peoples views mainly on the length of the cable run and if this is the major key to no signal.

Ideally once sorted i also i need to install a diseqC 2 way switch near the dishes for the other dish to be installed so not sure if this would work over that length of cable either ?

 

[canofan]

I would run a good quality cable above the ground to test.
100m is certainly a lot, if you do not get any result with the test then use an LNB with high gain or use a high quality line amp.
The diseqc switch, once this is sorted out is no problem

 

[cdtronix]

I would run a good quality cable above the ground to test.
100m is certainly a lot, if you do not get any result with the test then use an LNB with high gain or use a high quality line amp.
The diseqc switch, once this is sorted out is no problem

I was thinking of taking a 100m drum of cable and trying that, would it make any difference if i left it on the roll than completley pulled out ?

Any recommendations on a high quality line amp ? (not used these before)

+ would it make any difference if the which end the line amp is placed at, ie dish end or receiver end ?

thanks.

 

[rolfw]

Use WF125 or better still WF165, the last one I did at that length was a Triax 88cm rooftop installation using WF125 and Fracarro line amps set about 40m away from the LNB, but also worked next to the LNB. It was only supposed to be a 50m run, hence the choice of dish, I would have used a 1.2m dish I'f I'd known it was going to be 100m, 16 East is not as powerful as 28.2 East, so you want as big a dish as possible.

If you have a cable short, then it is likely to be water ingress or cable damage, best to replace them.

 

[cdtronix]

Use WF125 or better still WF165, the last one I did at that length was a Triax 88cm rooftop installation using WF125 and Fracarro line amps set about 40m away from the LNB, but also worked next to the LNB. It was only supposed to be a 50m run, hence the choice of dish, I would have used a 1.2m dish I'f I'd known it was going to be 100m, 16 East is not as powerful as 28.2 East, so you want as big a dish as possible.

If you have a cable short, then it is likely to be water ingress or cable damage, best to replace them.

cheers for the info Rolf, was going to use a 90cm dish for 16 east, but taking your advice think i will use a Triax 1.1m and cause of that cable short i did think instantly of some sort of damage to the cable so looks like it may be easier in the long run to just replace the whole lot. meaning get the spade out and dig

will post my results on this when done at the wkend.

 

[rolfw]

You may want to look at using direct burial WF165, it is practically indestructible.


A bit of a bugger to put connectors on though. ;)

 

[koansrc]

I would first test the cables using a multimeter or a battery and a bulb etc.
Chances are they are damaged.

Since there is very little chance that there are no (whatstheword) "manholes" in between the house and the dish along the 100m underground pipe run, I would try and find them. I would expect at least 2. I wouldn't be suprised if it turns out the cables aren't one long piece but are spliced along the way.

If the cables are in a tube / pipe underground and not directly in the soil and they are not totally cut, surely you can pull a new cable through by attaching it to the end of the old one.

 

[cdtronix]

I would first test the cables using a multimeter or a battery and a bulb etc.
Chances are they are damaged.

Since there is very little chance that there are no (whatstheword) "manholes" in between the house and the dish along the 100m underground pipe run, I would try and find them. I would expect at least 2. I wouldn't be suprised if it turns out the cables aren't one long piece but are spliced along the way.

If the cables are in a tube / pipe underground and not directly in the soil and they are not totally cut, surely you can pull a new cable through by attaching it to the end of the old one.

Did this job yesterday and went ok. There were manholes and the old cables were joined in various places and ran in 6" pipes underground. There were draw ropes there so pulling the new cable through took most of the time but came through ok.

Cable used was WF125 Underground, I ran 2 cables from 2 dishes to the house. 1 cable went to the excisting sky dish, i put in an in line amplifier approx 50-60m in and it helped boost the signal to the last stretch in the house where the signal was then around 85% quality and picked up all channels ok with the new Humax HD Freesat receiver.

The second dish used was a Triax 1.1m lined to Eutelsat 16 degs East. I had an issue lining this in the first place and had to move the dish and relised it was the trees around 10-20m away that were effecting the signal. you could see the signal coming in and out with the flow from the wind. managed to get a lock in the new postition and ran an offset LNB for Astra 19 degs East also, these went into a 2 way disecC switch which fed the 2nd cable.

Again another in line amp was used around the same distance as the otehr cable and Astra 1 was being received ok in the house.
16 degs East thoug was not being received vary well though, signal quality was around 50-60% and the picture was breaking in and out.

Im back there tomorrow to take another look at this, have another amp which im going to put in nearer the dish for the 1.1m and have some new f-connectors to put on but i think it could be the trees causing the issue with the signal in which case could mean move the dish to a ground mount just away slighlty, or get the customer to trim down his trees.

Will keep you posted of the final result and will probably get some pics uploaded. im hoping though fingers crossed the new amp may just do the trick.

 

[satelliteman]

Re: line Amp
Depends on the signal quality (BER, MER & dBuV) that the dish is currently receiving; good luck

 

[cdtronix]

Re: line Amp
Depends on the signal quality (BER, MER & dBuV) that the dish is currently receiving; good luck

Its the trees causing the issue with 16 degs east, was back there yesterday. im back again on friday to move the dish back around 20 metres to a new spot. that should do it then.

bugger of a job this one has been

 

[rolfw]

LOL, yes we all get them now and then. ;)

 

[cdtronix]

LOL, yes we all get them now and then. ;)

its not a major issue and the customer is ok with it. the worst bit was re laying all the cable. shouldnt take too long to move, its all good experience though ;)