Poor Signal Help!

cord

Fitted an 80cm dish with an 0.2db LNB with a twin output. Sky box on one cable and a FTA box on the other cable. Signal strength is 100% on the sky box with signal quality below 50%. The problem is that some channels are breaking up or freezing or going off completely, with the "no sat' signal" banner. One channel that is affected is the baby channel (Don't ask!!, but life would be easier if it worked!!, get the drift!!) I have checked with a neighbour and they have no problem receiving the channel with their sky dish and LNB. If I had a higher rated LNB would it help or is there such a thing as an amp to help the signal quality. Any help would be great.
Regards
Cord

Tony

is there another lnb you can try? Signal strength looks suspiciously high so may be the box itself unfortunately. An amp will not help and it should work ok with an 80cm dish

watty

Try rotating the LNB. A 100% signal is not impossible with an 80cm dish.

An amp or LNB does not affect quality. Too much signal though can reduce quality.

Cheaper 0.6dB or 0.7dB LNBs can perform better. 0.3 and 0.2 dB NF is (a) almost fictional, (b) no real improvement on 0.6dB.

See does very slow rotation of LNB increase Quality (should be at least 75%).

See does a wet cloth over front of LNB greatly reduce LEVEL. (May increase Quality slightly!).

If the level is still high you may be picking up interference.

How long is your cable run and is it smooth bends, no tight bends or kinks allowed?

cord

Thanks and sorry for the late response, life got in the way!! I have a fourway amp in my system with a few non F type connectors which might not be helping the quality. However BBC/ITV etc are comming in loud and clear. One thing I did notice is that the signal quality is not steady and keeps jumping between 50% and 60%??

Regards
Cord

Tony

can you give us a wiring diagram to show where the amp fits in?

cord wrote:

Thanks and sorry for the late response, life got in the way!! I have a fourway amp in my system with a few non F type connectors which might not be helping the quality. However BBC/ITV etc are comming in loud and clear. One thing I did notice is that the signal quality is not steady and keeps jumping between 50% and 60%??

Regards
Cord

watty

The quality can jump. But 50% to 60% is low

byte

Does the FTA box continue to work OK? What signal levels are it showing?

cord

Thanks everybody for the response. When I hook up the FTA box instead of the Sky box, the signal strength is 50% and Quality is 75%. Before anybody asks about comparing the channels, the FTA box hasn't had any new channels added to it, I just use it for the kids programmes. Not good at drawing so here's a verbal plan! LNB 1 to push in connection joiner and then to sky box. Sky box RF2 (With power on) to F140 Sky Amp, from there to two other TV's. I also have an TV Aerial going in to the Sky box providing the other TV's with RTE etc. LNB2 goes directly to FTA box. I have used screened cable through out, I can't say for sure if the coax was bought with digital sat in mind, so I don't know it's rating. That's as much info I have I think!!
Regards
Cord

watty

Only use F connector screw joiners

byte

Hmm. Right, firstly, the F140 is irrelevant here.

Can you explain the LNB1 to push in connector joiner? If it's a standard co-ax plug connector, then this is generally not suitable for satellite signals. Should use F-connectors (screw-on type).

You say the cable is screened, but is it double-screened? Ie, it should have a copper foil (at the very least even a tin foil) surrounded by the braid, which again should be copper (though you may be ok if it's a grey tin braid). If the cable only has braid and no foil, I'd blame the cable.

cord

The cable might be OK so, as it has braid and foil in there, all grey though. I am using a standard push fit jointer from LNB 1. I am testing both boxes on the same cabling and still there is a different in signal quality?. The RF2 fitting on the sky box is a standard push fit connection and is used for the transfer of digital sat signal so why no loss there? I am going to change all the push fits to F types, that is where I can.
Thanks to everyone for there help.
Regards
Cord
Ps Sorry, F Type from LNB1 and then push fit joiners

byte

Forget about the RF2 side of things, it's only handling UHF signals and isn't as fussy as satellite signals.

For the cabling between dish and box, you should be using F connectors and F coupler (back to back) if you need to join cables. I think the cable you have is RG6, which although not specifically for satellite signal, it should work.

On that note, how long roughly is the cable run between dish and box?

Also, it'd be nice to know if the FTA box works properly, or if the Skybox works in the other room where the other lead is. I presume the other lead is a straight run, with no joins? If Skybox continues not to work at either point, then I'd blame dish alignment or LNB not working properly.

watty

At 2000MHz, though RG6 has FOUR times the loss of CT100 / PF100, also roughly twice the loss at 1000Mhz.

The push on (IEC TV or Belling Lee) are pathetic. Usless for satellite, also they may not pass the 13V / 18V power switching well nor the 22kHz band select.

cord

Just found the reamains of the coil of coax, no marking on the coax itself, the PVC covering on the outside is a bit "wavey" on the surface and not plain. Its manufactured by Delta Crompton, the only other marking is E 9/45, propably means nothing. Cable runs are about 80ft+, I guess. I need to go and buy some F type connectors and couplers and then I will get back to you. I really do appreciate all the help, thanks again to every body.
Regards
Cord;)

Dec McC

Used to have the same problem myself and eventually sorted it by twisting the lnb at an angle and the quality shot up.

cord

Thank you for the info. I will have lots to try out at the weekend,if I can borrrow a ladder!!
Regards
Cord;)

TheDriver

On a whole side note, which ismore important, quality or strength? Doing a 60cm dish here and getting 75% quality and 60% strength on this glorious evening by holding arm up with dish! Must say I just held it up in the air and got astra 2d trio striaght away and moved a bit and got hotbird and astra 1 then but the arm got a bit sore!!!

Tony

TheDriver wrote:

On a whole side note, which ismore important, quality or strength?

Both are equally important but dont get hung up on the readings from the box they are indicative only, 60 and 75 are fine.

watty

Ultimately Quality. A long cable run will reduce the signal Level, but also noise equally so quality will remain the same. Boosting the Signal with an amplifiier will not help Quality as it boosts noise slightly more.

If quality below 50% / 60% (depending on FEC) then the picture is blocky, lower still and it freezes and breaks up, all even if signal is high. Similary level could be as low as 25% on a Quattro+ Multiswitch or distribution system or long cable and you might still have 80% or 90% quality.
For feeds that are 7/8 FEC you need higher quality. For broadcast at 1/2 or 2/3 FEC you can get picture with less quality.

FEC= Forward Error correction.

cord

Hello all!! back again having fitted my F type fittings. FTV box working with Quality and Signal over 70%. Swapping the sky box in its place Q drops to
50-% and S goes to 100%??? Looks like it might be the sky box?? Also even with the good Q and S on the FTV box it will not pull in the channels that I want, namely the childrens programmes, i.e., CBBC etc. Last two questions, even thought I rescanned for new ftv channels, can't find c4 movies (has to be put in manually?) AND why do some channels, a lot, even though they have good signal strenght vary their quality between 0% and 70+%. Thanks again for any help given.
Regards
Cord

watty

Sounds like a damaged cable or faulty LNB.

CBBC/Cbeebies only during daytime, becomes BBC3/BBC4 after 7pm

You may need to add transponders for BBC3/BBC4 and Film4. My FTA receiver needed Flim 4 transponder added recently.

Different receivers (esp. Sky Digibox) will give different level and quality signals for the same signal.

Try rotating LNB clockwise/anticlock wise up to 30 degrees VERY slowly while watching (or getting phone report) of Quality. The Quality bar updates slower than Signal.

cord

Thank you for the response. Some more questions if I may, when adding a transponder, if that's correct terminology?, what does the vertical or horizontal polarization mean? And with the FTV box is there any way of changing the output frequency again not sure of the terminology. I will explain what I mean. With the FTV box I am using two Satellite VHF/UHF combiners as I have only a single coax to that room from the attic. The problem is that when the FTV box is on it is interfering with TG4 and RTE2 on the aerial side of the combiner. I had the same problem with the RF2 on the sky box put I changed the Freq to 40 and the problem was solved. With the FTV box I don't know how to change the Freq'. The FTV box is a lidl camping set up, COMAG-PORTY II and it hook up to the TV via a scart. Again any help will be appreciated.

watty

Changeing the RF out is in a menu someplace.

Radio/Satellite/TV can be vertical or horizontal polarised on TV aerials the rods up/down/vertical or horizontal/flat. The LNB has equivalent of two miniscule aerials inside.

Get another coax.

cord

Thanks to everybody for their help. Loads of work to do!!

cord

Got a ladder today and twisted the LNB, as advised and Bob's your Uncle and.....!! Quality up to and over 70% and missing stations appeared. Thanks to every one again.
Regards
Cord

watty

You'd be amazed how many installers don't seem to know or understand that easy adjustment!

Applies to ALL non-circular polarised satellite systems.