Lost 12% of signal strength

[mmoloch]

I made some changes to my system and lost 12% of signal strength and I'm not quite sure what is the cause of the problem... these 12% are causing some problems in DVB-S2 transponders.

Old connection "diagram":




Now I added another dish with a motor diseqc 1.2:




Before the 2 dishes with 6 LNB's had a total of 20 meters of coaxial, now they have a total of 34 meters... did I lost 12% of signal strength because these extra 14 meters of coaxial?... or am I losing 12% in the motor diseqc 1.2?... because the diseqc 1.1 8x1 be connected at the input of the LNB on diseqc 1.2 motor?!

I can reduce these 34 meters to 25 meters, will make any difference?

On the dish with motor I can reduce the 36 meters to 22 meters...

[aplok]

Re: Lost 12% of signal strength

actual layout:
your lnb.out go through the [diseqc 1.2]=--=[motor]

	
[satbox]=

          =--=[diseqc 1.2]=--=[motor]:[dish.mobile]

                          =--=[diseqc 1.1]=---------[dish.static]-=[lnb1..6]

                                          =---------[dish.mobile]-=[lnb1]

my suggestion:
try tho bypass the motor bloc, this is:
your lnb.out go through the [diseqc 1.1] and
bypass [diseqc 1.2]=--=[motor]

( at least, find a way out to experiment this (manual switch, manual plugin, plugout ... ) )

	
[satbox]=

          =--=[diseqc 1.2]=--=[motor]:[dish.mobile]

          =-------------------=[diseqc 1.1]=---------[dish.static]-=[lnb1..6]

                                           =---------[dish.mobile]-=[lnb1]

[Satphoenix]

Re: Lost 12% of signal strength

If you didn't change anything at the dishes/lnbs the main failure soure is the motor and (normaly) a little part the cables.

To be sure about this connect (if possible for you) the 8m (from diseqc to motor) and 20m cable directly and see the result.
If it's ok, it's defenitly the motor.

If not, connect the 20m cable to your diseqc 1.1 switch and watch the result. If it's still not ok, connect the 20m cable directly to on of your lnbs.
If it's still not ok, it's the 20m cable or the adjustment.

This would be my way for a failure search in this case.

[rizwan]

Re: Lost 12% of signal strength

I think 34 Meter cable is too much, Other point is, try to remove the cables one by one from the Disec switch of different LNB, if any Connecter is not good, it decrease the over all strength

[sataday]

Re: Lost 12% of signal strength

I agree with aploc. Leave your setup as it was with the connection going from your box to you switch. (not your motor) Then run another cable from your switch to the motor and from your motor to the mororised LNB.

[Mobley3]

Re: Lost 12% of signal strength

I would agree with the suggestions with regard to connecting directly, also as it seems you have used longer cables what is the quality of these cables? you need to use at least ct100 cable and better if available.

Regards Mobley3

[Satphoenix]

Re: Lost 12% of signal strength

I think 34 Meter cable is too much...

Not really with newer/better cables.
I use 60 m cable incl diseqc-switch and have very good signal.

As written above, start a failure search and you will find the answer.

[mmoloch]

Re: Lost 12% of signal strength

I would agree with the suggestions with regard to connecting directly, also as it seems you have used longer cables what is the quality of these cables? you need to use at least ct100 cable and better if available.

Regards Mobley3

I am using new RG6 ITED of Iberosat, I know that is not a top quality cable but I think it is a relatively good cable.

I will follow the suggestions to try to locate the cause of the problem and will also reduce the length of the cables... for the use I give to my satellite system, manual switch, manual plugin or plugout is out of question!

[benchsirius]

Re: Lost 12% of signal strength

I would agree that the 20m of cable is likely to be the problem , plus every junction you install increases noise.

[thecrazybandit]

Re: Lost 12% of signal strength

If you use good quality cable to allow for the extra length there should be no problem i use over 30m of cable under ground and only loose a very small amount of signal

[mmoloch]

Re: Lost 12% of signal strength

This topic is related to this one:

http://www.satlover.eu/forum/satellite-hardware/51433-signal-differences-between-lnbs.html#post293843

It started raining and I can not go to the roof to test it, I removed the cables one by one from the diseqc 1.1 8x1 and the connections are all good.

[benchsirius]

Re: Lost 12% of signal strength

How close are your dishes, there is an effect called edge diffraction which can cause interference between dishes..

[Mobley3]

Re: Lost 12% of signal strength

How close are your dishes, there is an effect called edge diffraction which can cause interference between dishes..

As he has had all 3 dishes working before without problem I do not think that this would be a factor, the only difference now is that he has added a motor to one of the dishes, I believe the problem is in the cable connections

Regards Mobley3

Hi mmoloch, I have just had another look at your diagram and if I read it correctly you have one of the cables from the motorised dish Lnb ( I take it that it is a dual Lnb) going to the Output of the Diseqc switch? I think this is where your problem is. You have to run it to an input on this switch and run the output to the receiver, you then connect the other output from the Lnb to your other receiver.If I have misunderstood your diagram then obviously disregard all of this. I you were able to check out the direct cable connection then maybe you have already sorted out the problem.


Regards Mobley3

[mmoloch]

Re: Lost 12% of signal strength

As he has had all 3 dishes working before without problem I do not think that this would be a factor, the only difference now is that he has added a motor to one of the dishes, I believe the problem is in the cable connections

Regards Mobley3

Yes, I had the 3 dishes working without problems for a month, now just added the motor and 14 meters of coaxial cable.

My system:

Hi mmoloch, I have just had another look at your diagram and if I read it correctly you have one of the cables from the motorised dish Lnb ( I take it that it is a dual Lnb) going to the Output of the Diseqc switch? I think this is where your problem is. You have to run it to an input on this switch and run the output to the receiver, you then connect the other output from the Lnb to your other receiver.If I have misunderstood your diagram then obviously disregard all of this. I you were able to check out the direct cable connection then maybe you have already sorted out the problem.


Regards Mobley3

Yes, I have dual LNB's but I have two diseqc switches, one for each receiver, the diagram only show the cables and connections to one receiver!

The cable that is going to the Output of the diseqc switch does not come from the LNB, this cable should it go to the receiver but as I added the motor this cable will connect to the Input of the motor, in the diagram the cable is marked as LNB because is connecting to the Input where I should connect the LNB, as I have 7 LNB's are all connected in the Input.

Today is raining again and I do not know if I can go to the roof

[tech1010]

Re: Lost 12% of signal strength

I think it may be due to length of cables. Because i have experienced the same problem on 8 port switch.