Multi-sat / diseqc signal issue

There are 11 replies in this Thread which was already clicked 3,494 times. The last Post () by billybob69.

  • Hi all,
    I was hoping that you could give me some suggestions regarding the signal issue that I have on a multi-sat setup.


    I've got a dish with a multi-LNB holder and a diseqc switch. The dish is set to a compromise position (23.5e) so that I can try and get 28.2e, 19.2e and 13e.
    The signal on 28.2e and 19.2e comes through loud and proud.


    The signal issue is on the 13e. When I connect a cable directly between the 13e LNB and my Technomate receiver I get a signal quality of 57%. This is good enough signal quality to get the channels that I want without any picture breakup.
    However when I connect the LNB via the diseqc switch, the signal quality drops to near 0%. I've checked the cable between the LNB and the diseqc switch and that seems fine. I've tried a different diseqc switch and ensured that the numbering on the diseqc switch corresponds with the numbering on the diseqc setup on the receiver.


    Any other suggestions gratefully received!

  • There will be some signal loss from the switch and if you are already on the line of "just good enough signal quality", then maybe the switch pushes it over the edge. Not sure which switch(es) you tried, but the cheap ones will most likely have more signal loss than the better ones.

  • There will be some signal loss from the switch and if you are already on the line of "just good enough signal quality", then maybe the switch pushes it over the edge. Not sure which switch(es) you tried, but the cheap ones will most likely have more signal loss than the better ones.


    Hey, thanks for the quick reply.
    The switch is from a reputed manufacturer, Technomate I think. The other one that I tried was made by Konig.


    If there is a drop in signal quality by connecting it to a switch, surely there wouldn't be a drop from 57% to near 0% just by connecting it to the switch???


    bb69

  • surely there wouldn't be a drop from 57% to near 0% just by connecting it to the switch???


    bb69


    If it happens its true ¬
    Diseq switch does occur signal loss ! My opinion is you should first connect direct to hotbird lnb and tweak for better signal before trying again ?
    A small amount of movement can make a big difference.


    Which dish and LNB set up are you using ?
    :stoned:

    78cm dish on tm2300 metal gear motor + 1m Orb with tm2300 + 1.8m Channel Master on H-H floor mount + 80cm ISS with TM2300 AND Inverto Black LNB,inverto Unicable QUDL 42 LNB,- Global invacom Dscc LNB,- Triax KA LNB, - Yuri LNBF C Band YLF-CDP16C

  • You need to re-align the dish and have focal point on 19.2° east and not 23.5° east, if your dish and LNB setup do not have a Focal LNB (LNB in centre at the end of the dish Arm) and its something like a Triax dish setup with there Multibracket which does not use a focal LNB point then move just off 19.2° east and move towards 13° east.


    19,23,28 Astra Satellites are a lot stronger signal than Hotbird at 13° east

  • Thanks for the replies.


    If it happens its true ¬
    Diseq switch does occur signal loss ! My opinion is you should first connect direct to hotbird lnb and tweak for better signal before trying again ?
    A small amount of movement can make a big difference.


    Which dish and LNB set up are you using ?
    :stoned:


    I've already connected the LNB to the receiver and that is when I get the signal quality of 57%. I've tried tweaking the LNB, but 57% is the best that I can get. That is good enough quality to get 13e channels without any breakup.
    The issue as I see it is the dramatic drop in signal quality, when I pass it through the diseqc switch???



    The setup is a Metronic 65cm clear / transparent dish with a multi-LNB holder. The LNB picking up the 13e signal is a Alps LNB, connected to either a Technomate TM-4s or a Konig SATSWITCH200W Disqec switch. The receiver is a Technomate TM 7100HD.


    You need to re-align the dish and have focal point on 19.2° east and not 23.5° east, if your dish and LNB setup do not have a Focal LNB (LNB in centre at the end of the dish Arm) and its something like a Triax dish setup with there Multibracket which does not use a focal LNB point then move just off 19.2° east and move towards 13° east.


    19,23,28 Astra Satellites are a lot stronger signal than Hotbird at 13° east


    When I was setting up the dish, I tried it initially pointing at 19.2e, but there was rain fade on the weakest channels on 28.2e (the very channels that they most wanted to watch), therefore I had to turn it a little to the West and found that the best compromise position of having no breakup on 28.2e yet receiving a signal on 13e was went pointed at 23.5e.
    If I'm getting 57% picture quality on 13e (when directly connected), to my thinking it is a dish alignment problem?

  • A further update on this. I replaced the 60cm dish with a 80cm sky dish, but the same problem exists. If I connect the LNB directly to the receiver I get good signal quality, if I direct it via the diseqc switch, the signal levels drop to near zero.


    Anyone got any potential reasons for this?


    bb69

  • Did you try realigning your new dish on 19.2 like suggested before?


    Have you tried adjusting the skew of the 13e lnb?


    Have you tried swapping inputs to your diseqc switch?


    Have you tried replacing the diseqc switch with a simple male/male adapter (to test both cables together)?

  • Thanks for the reply.


    Did you try realigning your new dish on 19.2 like suggested before?


    No, I haven’t tried doing that. I’m not at all convinced that the issue is due to the signal levels at all. With the 60cm dish, I had signal quality of 56% with the 80cm dish, I’m having signal quality of 60% + when directly connected. When connected via the diseqc switch it drops to zero. The fact that it drop to zero suggests to me that it isn’t a signal issue?


    Have you tried adjusting the skew of the 13e lnb?


    I haven’t tried that, but as above isn’t all that is going to do adjust the signal quality by a few %?


    Have you tried swapping inputs to your diseqc switch?


    I have tried swapping the inputs around and made sure the switch / port number corresponds with the switch / port number on the receiver.


    Have you tried replacing the diseqc switch with a simple male/male adapter (to test both cables together)?


    I’m not sure I quite understand what you are suggesting there? I’ve connected the cable directly to the LNB’s to see try and rule out any issues with either the cable or the LNB.


    bb69

  • But there are two cables, one from the tuner to the switch and the other from the switch to the lnb. Use an adapter to connect the two cables together so they can both be tested together.


    If it is an elliptical dish, the further from the center, the signal will drop faster than with a circular dish.


    Also, signal level is a very relative term and the same setup connect to different tuners (and even different drivers ) can report big differences for what essentially is the same signal. And as the signal level falls before a certain level, sometimes it just drops to zero because there is not enough to get a sync. SO when adjusting a dish you sometimes see signal go from 90%->85%->70%->0%.


    I know you said you tried a different switch, but it may still be the cause. I currently have a faulty switch that took awhile to diagnose. I have two dishes each with a dual lnb. Port 1 from each lnb is connected to my multiple tuner receiver and port 2 from each lnb is connected to a diseqc switch which is connected to pc tuner card. Port 1 of the diseqc switch always worked, but port 2 was hit or miss. Finally I realized the only way port 2 of the diseqc switch worked, was if I was simultaneously using the same lnb on my multi-tuner receiver. So, the dual lnb was not getting enough power through the switch and needed power from the multi-tuner receiver to work. I am not suggesting that is your problem, just that quite often switches do not just fail completely, they exhibit intermittent problems.

  • The Zone 2 Sky dish is not exactly an 80cm dish its more like 70cm width by 59cm height but as it is elliptical in shape this means it actually performs better than a standard Oval/Round dish in Multisat configurations, the problem is the LNB arm needs proper modification and sometimes lengthening to acquire more accurate signals.


    I can assure you though just using it standard and un-modified i have had 13,19 and 28 east with acceptable signal levels with the main focus LNB being centered on 19.2 east .


    Your problem appears to lie with the switch type being used

  • But there are two cables, one from the tuner to the switch and the other from the switch to the lnb. Use an adapter to connect the two cables together so they can both be tested together.


    If it is an elliptical dish, the further from the center, the signal will drop faster than with a circular dish.


    Also, signal level is a very relative term and the same setup connect to different tuners (and even different drivers ) can report big differences for what essentially is the same signal. And as the signal level falls before a certain level, sometimes it just drops to zero because there is not enough to get a sync. SO when adjusting a dish you sometimes see signal go from 90%->85%->70%->0%.

    I know you said you tried a different switch, but it may still be the cause.
    I currently have a faulty switch that took awhile to diagnose. I have two dishes each with a dual lnb. Port 1 from each lnb is connected to my multiple tuner receiver and port 2 from each lnb is connected to a diseqc switch which is connected to pc tuner card. Port 1 of the diseqc switch always worked, but port 2 was hit or miss. Finally I realized the only way port 2 of the diseqc switch worked, was if I was simultaneously using the same lnb on my multi-tuner receiver. So, the dual lnb was not getting enough power through the switch and needed power from the multi-tuner receiver to work. I am not suggesting that is your problem, just that quite often switches do not just fail completely, they exhibit intermittent problems.


    Thanks for that reply, that has been really useful. I didn't realise that it was possible to have intermittent problems with a diseqc switch or that sometimes there are problems with 'powering' them. I've pretty much come to the conclusion that this is the problem. The cable run is 25metres + and goes through a few turns and runs close to electrical wiring, so I'm guessing that this somehow has an effect on the diseqc switch.
    I decided to scrap the diseqc switch and give a 6 degree monobloc a go. Now that has created a whole new set of problems......


    - - - Updated - - -


    The Zone 2 Sky dish is not exactly an 80cm dish its more like 70cm width by 59cm height but as it is elliptical in shape this means it actually performs better than a standard Oval/Round dish in Multisat configurations, the problem is the LNB arm needs proper modification and sometimes lengthening to acquire more accurate signals.


    I can assure you though just using it standard and un-modified i have had 13,19 and 28 east with acceptable signal levels with the main focus LNB being centered on 19.2 east .


    Your problem appears to lie with the switch type being used


    Many thanks for the reply.


    Would you care to expand on this? Modified in what way? What length do you suggest the arm should be / the distance that the LNB's should be from the dish?


    bb69

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