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Discussion Starter · #1 ·
I bought a Philips satelite TV switch (SDW5007GN17)for my Bell (DishTV) receiver.
It has two inputs that connect to the two LNB's on the dish.
One input (A) is labelled 13v/14v. The other, input (B) is labelled 17v/18v.
There is no reference to voltages in the instruction and I'm puzzled about the significance of these different voltages.
I'm aware that the LNBs require power to be supplied from the satelite receiver, but I'm confused about the reason for dual voltages.
If anybody can enlighten me, about this, i would appreciate it.
 

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The switch you describe is a universal switch. Depending on who manufactured the LNB it may require one voltage range over another. Just look up who made the LNB and the voltage requirement should be listed.
 

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Discussion Starter · #3 ·
The switch you describe is a universal switch. Depending on who manufactured the LNB it may require one voltage range over another. Just look up who made the LNB and the voltage requirement should be listed.
Thanks for your reply Tony. I have found some additional info about his myself.
Apparently satellites transmit their signals with different polarities. Depending on the transducer.
One set transmits the signal in a right hand spiral and the other in a left one.
So to receive the left spiral you connect 13 volts and if you wish the LNB to receive the right hand spiral, its connected to 17 volts.
I think that if a receiver is connected directly to a LNB, the receiver changes the voltage to suit what ever channel is being used.
 
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