seaboard18
01-07-2006, 05:35 AM
For those of you that are having switch trouble or no signal problems make sure that your LNB is not a DishPro. If it is you should see a Black Area on the LNB that says Dish Pro. All others that are not marked are Dish Twin and will work fine.
DishPro LNBFs are a new technology that is only supported in the newest receivers from Dish Network (Models 301, 501, 508, 721, and future 3-digit models). DishPro LNBFs and switches allow for longer runs up to 200 feet from receivers to the dish. DishPro installations are easier as there are fewer cables to run from the dish to the switch(es) for more than 2 receivers as well as simpler installations if more than 4 satellite feeds are needed (especially important now that 721s and 921s need 2 satellite feeds per receiver).
Quick lesson: all DBS providers have up to 32 frequencies to use per orbital slot. The Frequencies are opposite polarities either even or odd. Legacy LNBFs and switches can only transmit one polarity at a time down the feed cable to your receiver. Legacy switches and LNBFs use a voltage signal from your receiver to change the polarity of the LNBF it is connected to, 13 volts is odd, 18 volts is even. Since voltage will drop as the length of the cable gets longer, at some point the attenuation of the cable will drop the voltage from the receiver below 18 volts so that the LNBF can't switch to the even polarity even though the signal from the receiver is 18 volts the LNBF is only able to use the 13 volt or odd polarity.
DishPro is different as it will stack or transmit both even and odd signals down the same wire, by shifting the frequencies up so both polarities can travel the same feed to the receiver or switch. Since this is the case the LNBF doesn't need the receiver voltage to switch back and forth. A switch is necessary to be able to connect one stacked 119° feed and one stacked 110° feed to each receiver. The only way a legacy receiver will work with this arrangement of LNBFs and Dish Pro switches is with a DishPro adapter that can down convert the stacked frequencies to the standard odd or even only frequencies. Each legacy receiver has to use this adapter which must be installed within 10 feet of the receiver.
DishPro LNBFs are a new technology that is only supported in the newest receivers from Dish Network (Models 301, 501, 508, 721, and future 3-digit models). DishPro LNBFs and switches allow for longer runs up to 200 feet from receivers to the dish. DishPro installations are easier as there are fewer cables to run from the dish to the switch(es) for more than 2 receivers as well as simpler installations if more than 4 satellite feeds are needed (especially important now that 721s and 921s need 2 satellite feeds per receiver).
Quick lesson: all DBS providers have up to 32 frequencies to use per orbital slot. The Frequencies are opposite polarities either even or odd. Legacy LNBFs and switches can only transmit one polarity at a time down the feed cable to your receiver. Legacy switches and LNBFs use a voltage signal from your receiver to change the polarity of the LNBF it is connected to, 13 volts is odd, 18 volts is even. Since voltage will drop as the length of the cable gets longer, at some point the attenuation of the cable will drop the voltage from the receiver below 18 volts so that the LNBF can't switch to the even polarity even though the signal from the receiver is 18 volts the LNBF is only able to use the 13 volt or odd polarity.
DishPro is different as it will stack or transmit both even and odd signals down the same wire, by shifting the frequencies up so both polarities can travel the same feed to the receiver or switch. Since this is the case the LNBF doesn't need the receiver voltage to switch back and forth. A switch is necessary to be able to connect one stacked 119° feed and one stacked 110° feed to each receiver. The only way a legacy receiver will work with this arrangement of LNBFs and Dish Pro switches is with a DishPro adapter that can down convert the stacked frequencies to the standard odd or even only frequencies. Each legacy receiver has to use this adapter which must be installed within 10 feet of the receiver.