Faulty LNB caused Motor problem

[T_G]

I have had a problem with my Motor and Dreambox receiver for over two years. It would not turn properly. Sometimes it worked for a day or so without problems, then suddenly it woukld play up. I used to have to turn the receiver on and off, flick the channels and all sorts of tricks. I changed the cable, got a new motor, still the same - I sort of gave up and worked around it. Then some days ago the vertical channels stopped showing, so I suspected the LNB. Bought one from Ebay, and since I changed it the motor works like a dream as well!! :-sugar I am not sure how the LNB could affect the motor exactly, but it did. So if someone has a similar problem, don't forget the LNB!

 

[rolfw]

It may have been drawing too much current T_G, not allowing enough for the motor.

 

[BGonaSTICK]

Yeah, that's a bummer. Good things come to those who wait though!

 

[T_G]

i was really getting fed up with it all. Now i can actually move the motor. I did all day long just for the fun of it

 

[4dbennett]

i was really getting fed up with it all. Now i can actually move the motor. I did all day long just for the fun of it

Good info m8, from your experience we gain knowledge
thanks

Dave:-tree

 

[FooFighter]

Hi T_G,

Can you tell me what type of LNB you are using now ?

I am having exactly the same problems with my 500S, I was about to buy a Muliti-LNB bracket as I was getting so frustrated with the motor not working !

Many Thanks.

 

[T_G]

I bought already 2 of these, cheap and cheerful...
ebay 290194537710

definetly worth trying, but make sure your coax and connectors on dish and lnb are ok (not corroded etc).

 

[vma]

Dreambox Receiver's have a somewhat weak tuner: it does not provid much current and get's easily broken if you plug and unplug your LNB cable frequently without turning the receiver off first.

If you happen to have a Dreambox receiver and a lot of stuff hooked up on the LNB cable (i.e. LNB, DiSEqC-Switch, multifeed: several LNB's, Rotor, Inline-Amplifier, etc.) then you might be overloading the tuner. If you are on a treshold, you may have sporadic problems like those you described.

The best LNB's, when it comes to low power consumption are Sharp LNB's. They are not so easy to find, but when you come across them, don't hesitate.

Beware of cheap LNB's with 0.1dB Noise. That's simply untrue. Everything less than 0.6dB is simply impossible in practical terms, so it's better to invest in a quality LNB with low power consuption and overall good specs.

I operated my last system with three Sharp LNB's, a Motek Rotor, a 4/1 DiSEqC-Switch, Inline-Amplifier, 30m+10m cable and it worked fine.

Also, one should pay attention to not overload the antenna. Motek rotor's only support dishes up to 100cm, but they should be made of aluminium, not steel! Avoid loading the dish with too many LNB's, else the motor might overload with the weight, specially at more than 20E or 20W.

Cheers,
vma

 

[FooFighter]

Thanks T_G, and vma.

I will look for a local equivalent or sharp LNB's.

My rig is fairly new, it was professionally installed 12 months ago and I added the motor myself. ever since I have had sporadic problems like you describe.

Cable and connectors are all good so I suspect it is the LNB ( I dont know what type it is it came with the dish ).

Would an in-line amplifier make any difference to the power for the motor ?
My other thought was to get a small Diseqc positioner in case it was the dreambox not delivering the Diseqc signals.

Ill try a new LNB first and report back as well.

Thanks.

 

[T_G]

I can see what you are saying VMA, but I am not sure I can agree to all of it. The 0.1 D is questionable for sure, but that does not take away the fact that it is a brand new 2 years warranty LNB that is working perfeectly on two dishes I have. Whatever the larger power consumption would be compared to a Sharp, it is still much less than the previous one, which was faulty. Since I changed the LNB the dish is 100%.

So, I would suggest you get any new LNB, and before spending money on positioners, in line amps etc just get the basic set up right.

 

[FooFighter]

Ive got a new LNB on order, I will update the thread when I have it installed.

Thanks for the advise.

 

[learning]

confirms what ive suspected about my own lnb m8, deffo off to buy a new one now.

Thanks for sharing

 

[vma]

Just a side note: an inline amplifier does NOT solve these kind of problems! It will consume power and should ALWAYS be avoided, as it will not only amplify the signal, but also the noise!

It is only under certain rare circumstances that such an amplifier makes any diference and that has to do with signal/noise ratios.

Also, I never meant to discredit any LNB, I just wanted to point out that Sharp is famous for it's low power consuming LNB's. That does not mean that other LNB's are rubbish.

Finally, when I critizised 0.1dB LNB's, the goal was to make people aware, that the dB number should not be the only criterium, when purchasing an LNB, as most LNB's with fantastic looking 0.1 or 0.2dB do not meet such specs, while the mW consumption is a criterium at least as important (but unfortunatly as good as never written on the LN.

Cheers,
vma

 

[T_G]

Just a side note: an inline amplifier does NOT solve these kind of problems! It will consume power and should ALWAYS be avoided, as it will not only amplify the signal, but also the noise!

It is only under certain rare circumstances that such an amplifier makes any diference and that has to do with signal/noise ratios.

Also, I never meant to discredit any LNB, I just wanted to point out that Sharp is famous for it's low power consuming LNB's. That does not mean that other LNB's are rubbish.

Finally, when I critizised 0.1dB LNB's, the goal was to make people aware, that the dB number should not be the only criterium, when purchasing an LNB, as most LNB's with fantastic looking 0.1 or 0.2dB do not meet such specs, while the mW consumption is a criterium at least as important (but unfortunatly as good as never written on the LN.

Cheers,
vma

Hi VMA

Thanks for your comments, I appreciate it. This is what the forum is for, to exchange ideas and help other users. I am sure he is going to solve his problems.

Regarding the LNB, I think before he spends money on a better and more expensive LNB he should find the problem with a cheap one first.

I wonder if a top quality LNB would make much difference with a dreambox as it is a pretty limited tuner anyway.

 

[FooFighter]

Hi Guys,

Thanks for the info and comments.
Anyway, here's the situation :

Got a new cheapo LNB ( same make as T_G's ) and popped it on in place of the old one( turns out to be a Triax 0.3dB ). No difference !!!

So I took the whole rig down and dragged it into the house ( she who must be obeyed is out shopping !! ).

Stripped it down and used a short cable from receiver to motor and hey presto eveything worked. Then took the motor back up and mounted it on the pole, connected it up to the cable ( approx 15 Mtr length from receiver ) and powered up again no problems. ( turns east and west at steady speed ). Then took the dish up and mounted it on the motor, powered it on and works a treat ( turns nicely at steady speed ).

Finally connected the LNB to the motor, powered on dreambox, go to rotor control and I can send commands e.g. Moved to stored position and the motor starts to turn then dies out and stops. Nothing seems to bring it back to life except a full reboot and then it does the same again ( I get about 3-5 seconds of turn before it dies ).

I've changed the drop cable from motor to LNB for new, with new F-connectors everything is nice and clean and tight but as soon as I put the LNB on to the motor it wont work !!

Any ideas !!!

Its getting dark and raining here so i'm quitting for today, but tomorrow I will take the rig down and test it on completely new cable incase its that.

Im getting to the point of ditching the DB500 for a better model anyway. Is the 7020 better at handling motors ? or should i be looking elsewhere e.g. Technomate ?

What if I get a cheapo box just to do the turning ( I only want 16E at weekends for the footy ! )

Thanks guys.

 

[vma]

Hi,

Dreamboxes have weak tuners. I have a DM500-S and a DM7000-S and use both with my multiswitch, only. The DM7020-S I have been given had a tuner which wouldn't even scan all Hotbird transponders properly, so I returned it! It was not a defect, but a problem of that first batch.

I think your problem is due to the long cable and a tuner overload. There are acessories to feed the LNB-cable externally with power, like this Spaun SN 1418: http://www.spaun.de/?lang=en&modul=products&product=832109&productname=SN1418.

Unfortunatly it will cost about 100 Euro...

Things to try:

1) First class LNB cable. When you start using long cables, the quality makes a difference.

2) A different receiver, specially if you can use it for a test first.

I own a Clarke-Tech 2100 which is a cheap receiver with blind scan functionality and a much more robust tuner.

Dreambox receivers are not the only ones with problems: the famous Humax IRCI-5400 has power problems, as well. It you use it with rotors, you will have to replace the power source board after a few months. That is quite common with these receivers.

3) External power supply for you cable.

Good luck,
vma

 

[FooFighter]

OK, heres the results ......

Took the dreambox upstairs with a portable and put it as close to the dish as possible.
Made a new cable (good quality ) approx 2Mtrs long and hooked it all up.

Rotor turns for a while and then eventually dies the same as it does with the main cable ( probably lasted a bit longer maybe 30 seconds of use )

So my conclusion is :

a) My Dreamboxes ( both are DB500S ) are not strong enough to turn my rotor reliably, even when I use a LNB that rectified the fault for other people.

Different people may have different results, I think the DB500S tuners are quite variable in quality and strength ( I have had 2 other dreamboxes which wouldnt tune properly on strong signals ). Someone else might get better results just by replacing their LNB. I didnt.

My Questions :

Would another image make a difference ?
Would I get the same problems using a better dreambox, like a 7025 ?

What is the best alternative to the DB500, upgrade to 7000 series or go for another receiver ( I need to be able to CS between boxes in my house )

Thanks in advance.

 

[vma]

1. Would another image make a difference ?

Not in my opinion.

Would I get the same problems using a better dreambox, like a 7025 ?

Difficult to predict.

What is the best alternative to the DB500, upgrade to 7000 series or go for another receiver ( I need to be able to CS between boxes in my house )

I would try a loaned receiver. It should not be the general fault of Dreamboxes, though.

Just a question to you:

1) How big is your dish?
2) What material is it made of: aluminum or steel?

The point I am getting at: can it be that your dish is to heavy?

Also, can it be that the fault is with your rotor?

Cheers,
vma

 

[FooFighter]

1) How big is your dish? - 80cm
2) What material is it made of: aluminum or steel? - Steel

The point I am getting at: can it be that your dish is to heavy?

Rotor turns when LNB is not connected so I dont think dish is too heavy.

Also, can it be that the fault is with your rotor?

Possibly, but it turns OK up to the point I connect the LNB.

As in T_G's original post, he had replaced all cable, rotors etc. without success and then changed LNB and his worked. I have read other threads of people having problems with DB500 and rotors, I think they just arent strong enough . I think there is a fine line between there being too much current drain for it to work, everyones setup is different some people might get it working straight away, others might when they change LNB or cable. I think the main thing to note from this thread is that it MIGHT not fix your problem just by changing the LNB.

I was planning on upgrading one of my DB500's anyway so will probably go for a 7025 or alternative and hopefully that will be able to drive it OK.

Thanks for all your help and advise.