No Satellite Signal - Checked everything (I think)

alan4cult

Hi,

I have a multiroom setup, Sky+ and Sky. I have a quad LNB with three outputs used. My Sky+ is working perfectly, with high signal strength and quality on both inputs however my Sky setup isn't working at all.

I'm getting no signal strength nor quality and the lock indicator is reading not locked. Network ID 0000 and Transport Stream 0000

I have ruled out a faulty box as I have tested the box in the Sky+ setup and it worked perfectly. I have also checked the input connections.

What else could be wrong. The funny thing is yesterday I got it working for about 2 minutes and the signal strength/quality was very high but it just stopped working again.

Any help much appreciated

eddiem74

I am sure the experts will be along, however I would check the f-connectors are ok at box, and LNB, perhaps even redo them. I would also check the cable run if exposed/outside just to make sure no obvious damage.

I would also swap the connection on the LNB to the unused one to see if it makes any difference.

Tony

+1

eddiem74 wrote: »

I am sure the experts will be along, however I would check the f-connectors are ok at box, and LNB, perhaps even redo them. I would also check the cable run if exposed/outside just to make sure no obvious damage.

I would also swap the connection on the LNB to the unused one to see if it makes any difference.

alan4cult

Right, I've redone the F connectors so I think there is either a problem with one of the F connector joiners or the LNB or perhaps as you said cable run.

Part of the cable is actually chased through the wall as it was part of the terrestrial system I once had so I can't really check that.

I don't have a spare LNB so it may be tough to rule out that?

Tony

swap around the lnb connections as suggested earlier

alan4cult wrote: »

Right, I've redone the F connectors so I think there is either a problem with one of the F connector joiners or the LNB or perhaps as you said cable run.

Part of the cable is actually chased through the wall as it was part of the terrestrial system I once had so I can't really check that.

I don't have a spare LNB so it may be though to rule out that?

gazzer

Sorry of jumping into this thread but I have a very similar problem and didnt want to start a brand new thread for it.

I have a spare lnb connection on my sky dish and have a spare sky box so I bought some cable and connectors. I conected the cable to the spare LNB and to the sky box but I am getting the "No Satellite Signal" message. I have swapped the LNB connections around on the dish and while my SKY HD and other sky box are still working I still cant get a signal on the spare lnb/box.

I presume this means that the box is faulty??? Do I have a way to check this??

Thanks

Tony

Plug the box in in place of your sky hd, if it works the new cable/connector is faulty, if it doesnt the box is faulty.

gazzer wrote: »

Sorry of jumping into this thread but I have a very similar problem and didnt want to start a brand new thread for it.

I have a spare lnb connection on my sky dish and have a spare sky box so I bought some cable and connectors. I conected the cable to the spare LNB and to the sky box but I am getting the "No Satellite Signal" message. I have swapped the LNB connections around on the dish and while my SKY HD and other sky box are still working I still cant get a signal on the spare lnb/box.

I presume this means that the box is faulty??? Do I have a way to check this??

Thanks

snaps

alan4cult wrote: »

Right, I've redone the F connectors so I think there is either a problem with one of the F connector joiners or the LNB or perhaps as you said cable run.

Part of the cable is actually chased through the wall as it was part of the terrestrial system I once had so I can't really check that.

I don't have a spare LNB so it may be tough to rule out that?

Terrestrial cable is usually no good for satellite use.

alan4cult

snaps wrote: »

Terrestrial cable is usually no good for satellite use.

But it has worked for years in my house and still works on my Sky+ setup. Why is it no good? Isn't it still coaxial cable?

Tony

alan4cult wrote: »

Isn't it still coaxial cable?

Forgive me but its like asking is not all water pipe the same. Because satellite tv uses much higher frequencies it needs a much higher grade of cable. You can get away with lower grade of cable on shorter runs which is probaly why yours is working ok. Its like most things, it works fine until it doesnt work. Theres very little difference in price these days for good quality cable so my advise would be to use Tx100, PF100 etc where possible.

bmaxi

snaps wrote: »

Terrestrial cable is usually no good for satellite use.

Yes, I've heard that before and though I've used it, I've never had any problems. Do you mean it's not as good in, say, borderline reception cases, or, as is the case with HD, just promoting the more expensive item? Maybe someone could explain why it is no good.

Tony

Its about promoting the right item not the most expensive one.

John mac

http://www.wrightsaerials.tv/articles/coax-cable-quality.shtml


Some info here about coax.

bmaxi

Tony wrote: »

Its about promoting the right item not the most expensive one.

No doubt you're right but that's not really an explanation.

Tony

bmaxi wrote: »

No doubt you're right but that's not really an explanation.

I explained earlier in the thread

Apogee

bmaxi wrote: »

Yes, I've heard that before and though I've used it, I've never had any problems. Do you mean it's not as good in, say, borderline reception cases, or, as is the case with HD, just promoting the more expensive item? Maybe someone could explain why it is no good.

Because the signal losses at the frequencies used for satellite are too high with terrestrial cable.

It's stupid to spend a few hundred euro on a satellite system, and then compromise the whole thing - both in terms of reliability and lifetime - just to scrimp on a few euros.

http://www.wrightsaerials.tv/articles/coax-cable-quality.shtml

watty

Also screening.

The screen on cheap cable is rubbish so local DECT, GSM, 3G phone* knocks out FOUR groups of channels. Also possibly Licensed security video at 1.4GHz, Radio Amateurs at 1.2GHz too.

The Sat IF cable also then "transmits" on 750MHz to 2200MHz approx interfering with TG4, DECT, GSM 900, 868MHz SDR, GSM 1800 and 3G/HSPA.

So while "loss" is important, foil screen and heavy braid for screening is too.

Bad or wrong cable or too sharp a bend, crushed cable or dodgy connectors can all do very strange things to specific frequencies, knocking out all or a bunch of channels.

A lot of "terrestrial cable" is pretty poor even for ordinary TV allowing interference from motors, lighting and passing cars to even make a digital (DTT) signal go blocky or put speckles on analogue.

I only use Sat grade for "ordinary TV" too. The "regular" tv cable is a joke with something more like spider's web than braid as screen. Nor is it weatherproof at all. (Regular satellite cable actually is not totally outdoors proof).

(*Not just your phone but a phone mast 1km away or a neighbours mobile phone can potentially interfere or suffer interference!)

alan4cult

I realise that terrestrial cable is of poor quality for use with satellite systems but most older houses are wired using this cable and chasing new cables is costly.

Tony

alan4cult wrote: »

I realise that terrestrial cable is of poor quality for use with satellite systems but most older houses are wired using this cable and chasing new cables is costly.

Yes thats very true so its best minimise the amount of "old" cable in the run and replace where its easy enough to do so.

watty

alan4cult wrote: »

I realise that terrestrial cable is of poor quality for use with satellite systems but most older* houses are wired using this cable and chasing new cables is costly.

Often you can use old cable to pull in nylon builders cord and use that to pull in new PF100, maybe with silicone polish as a safe "grease" to pull it without damage to screen.

If the duct is big enough pull in a length of builders orange nylon cord at same time as coax to add a second coax or Cat5e network cable later.


[* see mistake I fixed in quote? ]

alan4cult

Yes I guess you're right "most houses". Might try rechasing the cables sometime with the method suggested above.

Funnily enough the two inputs to my Sky+ box run completely different routes. The first one is through the "old" terrestrial route as I mentioned but the other runs outside the house and is in fact all satellite cable but the Average Signal Quality/Strength of the satellite cable is more or less the same as the terrestrial.

alan4cult

Just another question,

The braided copper that is contained in satellite cable, what does it do? Is it a conductor itself or is it part of the interference shield?

watty

the signal flows on INSIDE surface of foil and outside surface of inner core.

The braid and the foil both provide the screen.

The foil easily cracks and the braid shorts over the cracks for screen/shield and signal. Too many cracks due to too much handling degrades the cable.

The spacing from outer surface of core and inner surface of screen is very critical for the RF signal performance, hence the cable must not be stretched, kinked, sharp bends or in any way physically impaired/damaged.

watty

alan4cult wrote: »

the Average Signal Quality/Strength of the satellite cable is more or less the same as the terrestrial.

Also it's a very coarse measurement at only one frequency, not over the 950MHz to 2100MHz full band. That doesn't indicate interference in/out at all of course on a different frequency.

See what difference there is during very heavy rain.

Also it's not a very accurate "meter" only an indication.
My signal "level" is near 50% and my "quality" is near 90% on Sky box.

The quality is the only important one in one sense. I have a distribution system fed by 95cm dish hence strange "bars".

Batesy

Hey Watty, when you say 4 groups of channels what do you mean here?

I'm having grief with certain channels e.g (Sky News HD, Sky Movies Premier, NME TV etc)

I'm using a Thomson HD box from 2006.

watty wrote: »

Also screening.

The screen on cheap cable is rubbish so local DECT, GSM, 3G phone* knocks out FOUR groups of channels. Also possibly Licensed security video at 1.4GHz, Radio Amateurs at 1.2GHz too.

The Sat IF cable also then "transmits" on 750MHz to 2200MHz approx interfering with TG4, DECT, GSM 900, 868MHz SDR, GSM 1800 and 3G/HSPA.

So while "loss" is important, foil screen and heavy braid for screening is too.

Bad or wrong cable or too sharp a bend, crushed cable or dodgy connectors can all do very strange things to specific frequencies, knocking out all or a bunch of channels.

A lot of "terrestrial cable" is pretty poor even for ordinary TV allowing interference from motors, lighting and passing cars to even make a digital (DTT) signal go blocky or put speckles on analogue.

I only use Sat grade for "ordinary TV" too. The "regular" tv cable is a joke with something more like spider's web than braid as screen. Nor is it weatherproof at all. (Regular satellite cable actually is not totally outdoors proof).

(*Not just your phone but a phone mast 1km away or a neighbours mobile phone can potentially interfere or suffer interference!)

watty

Batesy wrote: »

Hey Watty, when you say 4 groups of channels what do you mean here?

I'm having grief with certain channels e.g (Sky News HD, Sky Movies Premier, NME TV etc)

I'm using a Thomson HD box from 2006.

The LNB gets 4 signal conditions:
13V or 18V for Vertical or Horizontal Polarisation.
22kHz tone off or on for Low or High Band.

Thus 1.4GHz approx on the sat coax can refer to
11.xx GHz Vertical
11.xx GHz Horizontal (likely 10MHz to 20MHz offset)
12 GHz Vertical approx
12 GHz Horizontal (likely 10MHz to 20MHz offset)

Though the channels are 25MHz to 30MHz wide, the offset between channels is as small as 5MHz, typically 14MHz as alternate channels use alternate Horizontal/Vertical polarisation.

Actual LNB conversion is about 9.75 (tone off) and 10.6GHz (tone on) subtracted from the Satellite frequencies here
http://www.lyngsat.com/28east.html

A kink, crush or hole in cable can affect one part of the 0.95 .. 2.1GHz IF on the cable.

The coax carries a signal like that inside a radio, not the real satellite signals as they are x10 too high a frequency. The LNB (box on end of arm of dish) is actually the most important part of the satellite receiver. The Dish collects enough signal for it, like a lens can collect sunlight and set fire to paper.