Improving Sky Digital Signal

Ronan H

Hi all, anyone familiar with the menu system on Sky Digital will know that when you go into Services >> System Setup >> Signal Test you can see the Signal Strength and Signal Quality... Well on my system both of the bars are quite low on the scale (less than 50%) and i was wondering if theres any way of getting them up to the top? Is it as simple as moving the dish small amounts until it improves or should i speak to someone who installs the system?

If the rain is particularly heavy i usually lose signal altogether and im wondering if the signal wa stronger would it be more resistant to the weather?

Has anyone experienced this?

Any input would be great thanks...

Signal Head :cool:

L1011

Dish might be too small (UK sized is too small for anywhere, really, but definately too small for Ireland), or might not be totally aligned well. Or your cable run could be poor (not satellite-quality cable, joined, etc).

The stronger the signal the more reliable in bad weather, yes.

watty

The lower quality bar is the imprtant one, It takes 10 to 20s to update, so changes must be slow.

1st do the LNB rotation (skew) as this is easest!

Then VERY small movements

2nd: DO NOT loosen the East/west adjustment.
Then the up/down (elevation). Tighten up slowly while holding dish and watching quality.

3rd: Finally the East / West (Azimuth). Again VERY small VERy VERY slow movement. Tighten each bolt a small amount alternately while watching quality as the dish may twist otherwise.

Sparky

Using the digibox as a guide takes ages. I bought a cheap sat meter that goes in series with the lnb and the digibox (to get 12/18v power for meter and LNB, a 12v battery may even do the trick)
It worked way better and I only sdjusted my dish by mm's, elevation being the master in making the signal better.

I even adjusted the sens. setting to low on the meter to get an even better signal.

satworld

try an inline amplifier i saw a guy in the fs general selling them

L1011

satworld wrote:

try an inline amplifier i saw a guy in the fs general selling them

:eek:

These do NOTHING to improve the signal!

Amplifiers exist solely to prevent the signal dissapearing over long, long cable runs. In a domestic setting, they will make signal problems worse as they also amplify the noise.

watty

If someone makes lots of stupid sugestions then they get banned.

The amplifiers just drive long long cables. Maybe 100m.

As Myob says, they don't help. THe LNB is actually the front part of the Satellite receiver and its output is a very high level IF signal. You have to get the quality level up by Dish/LNB adjustment.

I use the actual receiver on a short cable at the LNB during setup. Moving the receiver to the other end of a 30m cable run the level drops from FULL 100% to about 75% 80%. The quality actually rises slightly from about 80/85 to 85/90

matty2003

I have a standard sky installation and have only ever got 50% signal strength and maybe 40% quality. I reckon the reason is that the installer just connected the new cable from lnb to the old ntl cable. I'm going to replace this with one length of ct100 or similar.

Hoepfully this will improve things, although it's really only in heavy rain that it's a problem.

watty

sounds not to well aligned too.

matty2003

What do you mean by LNB rotation (skew)?

I've already tried the East/West and I reckon it's original position was giving the max signal, albeit 50%

Skyuser

Some Advice : NEVER move your dish unless you have a sat meter. It's a nightmare.

watty

matty2003 wrote:

What do you mean by LNB rotation (skew)?

I've already tried the East/West and I reckon it's original position was giving the max signal, albeit 50%

Clockwise / anticlockwise rotation of LNB. It either rotates in holdeer when screws loosened or on some models "clicks" around in the fixed angle plastic casing.

Blaster99

When I installed my setup I obviously noticed that the LNB can be rotated. I have very good SQ so no worries there, but why would rotating the LNB improve SQ?

L1011

Blaster99 wrote:

When I installed my setup I obviously noticed that the LNB can be rotated. I have very good SQ so no worries there, but why would rotating the LNB improve SQ?

Signal doesn't hit the dish exactly square-on. It gets reflected at a slight angle to the LNB. LNB can kinda handle it, but by skewing it to be correct with the dish you get the least loss.

watty

Yes ..

Well some signals are -- Polarised (H) and some | Polarised (V), the quality is very affected by distortion and Noise. As tiy get about / or \ 45 degree to correct polarisation, the desired signal is quite reduced and noise isn't as it has * all the polarisations. Also some channels the | and -- signals overlap a bit in frequency, which doesn't matter if the LNB is ligned up.

A bit like some TV sations nedd Vertical rods and others need horizonatl on ordinary TV aerials.

Also the LNB perfectly horizontal is only correct if you dish is pointing due south and ane the Satellite has "normal" alignment (some don't).
As you fo further East or west from due South the LNB needs to be twised more as the satellites "appear" more and more at an angle, evn if "normal".

If you watch the LNB angle on a motorised dish , it magically seems to tilt on its own, because the motor is mounted at an elevation = 90-latitude.

watty

myob is taking about LNB up/down angle to the dish, which is fixed by design of dish and LNB holder. The LNB "points" roughly at the center of the area of the dish. This can't normally be adjusted and if fixed, shouldn't be. On some very old dishes the arm has a sligh up/down adjustment on the dish, partially to fine tune elevation.

Ronan H

Wow, cheers for all the info guys (i use the term collectively), i didnt expect such a detailed response. Having said that i didnt expect to forget that i posted the thread for 2 weeks either :rolleyes:

Em... Im not sure that ill take a risk adjusting the dish etc... based on years ago when my Da had a dish when Sky came to Ireland first and ya could get it free, it was a friggin nightmare shouting from the back garden to the house to adjust it...

My system has about 30m of cable id say. The dish is totally diagonally opposite where the digibox is so they actually couldnt be further away from eachother, bar being on someone elses property.

Would it make any difference to JUST buy a better quality cable for the time being or would that be a waste?

Again thanks for all the replies...

Skew Head

byte

Take a look at the cable, and describe it here.

If it's grey braid on tinfoil, then it probably would degrade signals over 30 metres. Satellites should be installed with copper braid and copper foils (CT100, etc) for optimum signals.