נשלח: 21 אוגוסט 2007, 15:41
מצאתי את ההסבר הזה עבור תפקוד מולטיסוויטש.
אני בטוח שזה יענה להרבה שאלות.
אבל עדיין לא הבנתי, אם משתמשים במולטיסוויטש, האם ניתן גם לחבר דייסק לפני הסוויטש (לריבוי LNB)
To better understand how a multiswitch works with a satellite antenna, lets get an understanding of how the two work together.
The LNB on your satellite dish is capable of tuning to a satellite transponder that is broadcasting in either left-hand or right-hand circular polarity. A technical explanation of this is pretty involved and for the purposes of this explanation you'll just take our word for it. When you tune to a channel on your receiver, the receiver sends a switching signal back up the coax cable to the LNB in the form of a 14-volt or 18-volt DC voltage level to select the correct polarity for the transponder you have requested. This is why you cannot use a splitter for adding additional DSS receivers. If you do, the LNB gets a conflicting set of commands from the two sat receivers if they both try to access transponders of differing polarity. As a result, you can get a signal on one receiver while not the other if different transponders have been selected by each. You can set up two DSS receivers on a dish with a dual LNB using a dedicated line for each receiver. If you want to set up more than two receivers then you need a multiswitch.
A multiswitch is basically a box that contains splitters and A/B switches. The outputs of each LNB are connected to the A and B inputs of the multiswitch. In this configuration, one LNB is dedicated to left-hand polarity transponders and the other LNB is set up for right-hand polarity. The inputs to the multi-switch from the LNBs are split for either 4 or 8 outputs each (more if a larger multiswitch is desired). These split outputs are paired and connected to a series of A/B switches such that one side of the switch sees input A and the other side sees input B.
The outputs of the multiswitch are routed to each receiver you have in your household. When you tune to a channel, instead of the LNB being switched to the correct polarity, the 14-volt or 18-volt signal selects either transponder A or B by toggling the A/B switch. The LNBs are no longer switched when you change channels. Instead, the switching occurs inside the multiswitch (hence the name) and the correct polarity is selected for the desired channel/transponder.
Note that there are two different types of multiswitches available - passive (unpowered) and active (powered). If you have cable runs longer than 100 feet for any receiver, a powered multi-switch is highly recommended. The long run can degrade the voltage output from the receiver and the multiswitch may not work properly if the voltage drop is too great. A powered multiswitch detects the difference in the voltage levels and compensates for i
אני בטוח שזה יענה להרבה שאלות.
אבל עדיין לא הבנתי, אם משתמשים במולטיסוויטש, האם ניתן גם לחבר דייסק לפני הסוויטש (לריבוי LNB)
To better understand how a multiswitch works with a satellite antenna, lets get an understanding of how the two work together.
The LNB on your satellite dish is capable of tuning to a satellite transponder that is broadcasting in either left-hand or right-hand circular polarity. A technical explanation of this is pretty involved and for the purposes of this explanation you'll just take our word for it. When you tune to a channel on your receiver, the receiver sends a switching signal back up the coax cable to the LNB in the form of a 14-volt or 18-volt DC voltage level to select the correct polarity for the transponder you have requested. This is why you cannot use a splitter for adding additional DSS receivers. If you do, the LNB gets a conflicting set of commands from the two sat receivers if they both try to access transponders of differing polarity. As a result, you can get a signal on one receiver while not the other if different transponders have been selected by each. You can set up two DSS receivers on a dish with a dual LNB using a dedicated line for each receiver. If you want to set up more than two receivers then you need a multiswitch.
A multiswitch is basically a box that contains splitters and A/B switches. The outputs of each LNB are connected to the A and B inputs of the multiswitch. In this configuration, one LNB is dedicated to left-hand polarity transponders and the other LNB is set up for right-hand polarity. The inputs to the multi-switch from the LNBs are split for either 4 or 8 outputs each (more if a larger multiswitch is desired). These split outputs are paired and connected to a series of A/B switches such that one side of the switch sees input A and the other side sees input B.
The outputs of the multiswitch are routed to each receiver you have in your household. When you tune to a channel, instead of the LNB being switched to the correct polarity, the 14-volt or 18-volt signal selects either transponder A or B by toggling the A/B switch. The LNBs are no longer switched when you change channels. Instead, the switching occurs inside the multiswitch (hence the name) and the correct polarity is selected for the desired channel/transponder.
Note that there are two different types of multiswitches available - passive (unpowered) and active (powered). If you have cable runs longer than 100 feet for any receiver, a powered multi-switch is highly recommended. The long run can degrade the voltage output from the receiver and the multiswitch may not work properly if the voltage drop is too great. A powered multiswitch detects the difference in the voltage levels and compensates for i
