Twin lnb with motor setup pronlem

[Conaxthewarrior]

Hello all,
My vu+ Duo setup is a twin lnb connected to a triax motor. All works well until the 2nd tv sat box is swiched on and tuned to the same tv program. Then, both tv's show running diagonal lines!
When 2 different tv channels are selected, the tv pictures are crystal clear, that is, the interference only occurs when the same channel is selected on both sat boxes.
After some time, a single "out" of the twin lnb blows! Later the other ceases, leaving the whole lnb dead whereupon, a replacement is necessary. Todate I have changed 3 times, each time with a different manufacturer.

I've tried several 2nd sat box lnb setups - single lnb on zero volts, single lnb on 12/18v later twin lnb ....but the lnb eventually still blows.

Any ideas as to what I could do to solve this anyone?

[Rob van der Does]

What do you mean by "the 2nd tv sat box"?

[Conaxthewarrior]

By 2nd tv sat box, I mean the secondary satellite reciever connected to the twin lnb. The main reciecer is my vu+ duo (that is, the one used most & connected to the motor).The other reciever is used occationally in another room. I think it's a peculiar problem that the lnb burns out after time, I would have expected that twin lnb's be made to run with a motor on one output and a reciever on the other without problems.

[Rob van der Does]

Still don't get your setup: please explain which LNB is connected to which tuner of which box.
And how is the second box connected?

[canthackit]

if the lnb is blowing it usually indicates the the coax is wired faulty.

check and make sure that none of the strands are poking through to the single core.

dropping them, throwing them, might break them it wont blow them.

regards: canthackit

[Conaxthewarrior]

Thanks,just checked as suggested and have renewed the satellite wiring. Presently the tv picture from both satellite recievers are ok but the line interference/lnb blowout problem usually occurs after a good many hours of lnb use (last took 2 months) , so I'll keep an eye on the situation & let you know.

[Conaxthewarrior]

Ok,VuPlus Nl, here's a more detailed setup explanation.
The lnb is a standard single reciever with twin outputs, made by "maximum". The specs as appearing on the block are:-
Input 10.7-12.75Ghz
Output 950 - 1950Mhz
1100 - 215 Mhz
LO 9.75 - 10,6 Mhz
Gain 65dB

One output of the lnb is directly connected to the "lnb in" of the motor (thereafter the "reciever out" of the motor is connected to the lnb1 of my vu+ duo)
The other lnb output is directly connected to" lnb in" of a different satellite reciever, a "Maximum S2000 FTA PVR, which I've set up as twinlnb.

Opps! Made a mistake with the motor manufacturer. It is actually a "Rotor Sat HH120" model which a turns a "Triax" 110cm dish.
Motor power specs are:-
Operational power supply - 13/18V dc
Consumption in standby mode - 190mA
Starting movement consumtion (max) - 350mA

Hope all this helps.

[Rob van der Does]

1) I take it that with "thereafter the "receiver out" of the motor is connected to the lnb1 of my vu+ duo" you mean it is connected to tuner A of the DUO?

2) Tuner B of the DUO has been set to "Loopthrough to tuner A"? It should.

3) The setup of the Maximum as "twin LNB" I don't understand. Is it a twin-tuner PVR? And the LNB is connected to Tuner A?
And if so, there is a loopthrough to the second tuner?
You understand that the Maximum can only look at the satellite the DUO has turned the dish to?

[Conaxthewarrior]

My Vu Duo has the following setup:-
Tuner A BCM 7335 DVB-S2 NIM (Internal) DVB-S2 Positioner USALS
Tuner B BCM 7335 DVB-S2 NIM (Internal) DVB-S2 Loopthrough to tuner A

and the other reciever has a single LNB in (A) - with a permanant loopthrough to B. (It is not a top of the range reciever like the VU+ duo, only a free to air reciever with PVR and motor facility when set up as such). It's only used occationally and so motor control is always with the Vu+ Duo

[Rob van der Does]

OK, connections seem to be OK (although a bit pity for the DUO to have only one LNB.......).
Using the secondary receiver should in no way have any influence on the DUO. Since it does I presume the Twin-LNB is faulty; I can't see any other explanation for that.

[Conaxthewarrior]

Thanks VUplusNL.
The lnb blowing problem takes time and since starting this thread, I've had a lot of help & been advised to and have (a) renewed all satellite cables b) rechecked the setup of both recievers & (c) renewed the lnb, so perhaps the fault has been corrected - I'll post if and when the problem occurs.
Stop Press
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Just turned on the Vu+ Duo and the motor behaved very oddly. It moved the parabol from E to W erratically, that is, in short and long movements then back again.....I shook the cable on the motor (at the "to reciever" output) slightly and the motor suddenly returned cleanly to 28e where it was originally. I think thats the problem, theres some kind of short in the motor where the "to reciever" output is and somhow this is causing slow overload of the lnb. Inspecting the "to reciever" output, I see there is some side to side movement at the "to reciever"/satellite cable screw connection. It looks as if the whole output here is shorting occationally.
I've also found an upbuild of static electricity on the mounting itself. The parabol & motor are fixed to a 75kg non conductive weight so theres static electricity all over them, building up, unable to ground. I have connected a permanent earth to the mounting, so hopefully now, any stray charge will be dissipated. I'll post after some days & inform if the odd motor movments reoccur.