Making a 4x1 multiswitch

[sinebar]

Any circuits out there for making a multiswitch?

 

[Mr Tony]

what are you trying to do? split a dual LNB to 4 receivers?

They make 2x4 and 3x4 multisiwtches (the extra port is the antenna). Works real good

 

[Darin]

4x1 should be a multi-sat system to one receiver. Technically, there'd never be a need for a 4x1 switch... since a single receiver would never need odd & even transponders at the same time, you wouldn't need two inputs for each satellite slot like you normally need for multi-receiver setups. In other words, a 2x1 multi-sat multiswitch would provide the same functionality as a 4x1 multiswitch. Therefore, all you'd need would be to have sat-C and sat-B combined as normal, as one input, then 101 as the 2nd input. You'd then need something to detect 22khz to switch between the two inputs.

 

[sinebar]

4x1 should be a multi-sat system to one receiver. Technically, there'd never be a need for a 4x1 switch... since a single receiver would never need odd & even transponders at the same time, you wouldn't need two inputs for each satellite slot like you normally need for multi-receiver setups. In other words, a 2x1 multi-sat multiswitch would provide the same functionality as a 4x1 multiswitch. Therefore, all you'd need would be to have sat-C and sat-B combined as normal, as one input, then 101 as the 2nd input. You'd then need something to detect 22khz to switch between the two inputs.

So all I need is a switch with 1 input for sat A and 1 input for sat B and 1 output for the reciever? I have a oval dish with 3 LNB's and the instructions show a multiswitch with 2 sat A inputs and 2 sat B inputs.

 

[Darin]

Yes, that should be all you need. The reason your instructions show that is because all the multiswitches they are typically used with are designed to support at least four outputs. Any time you have more than one receiver, you need separate inputs from the same satellite slot, to cover instances when both odd and even transponders are being requested (from two different receivers) from the same satellite at the same time. Since that won't happen with a single receiver setup, you technically don't need two inputs per slot.

But then the obvious question becomes... why? A 4x4 multiswitch isn't very expensive, is an easy solution, and gives you the option to add more receivers later should the need arise. By the time you build a 2x1 multiswitch yourself, I'd imagine it'd be more than a 4x4 off the shelf. Heck, for that matter, you could buy a Phase III dish with built-in 4x4 multiswitch, and sell your current dish, and end up not spending much at all.

 

[sinebar]

Yes, that should be all you need. The reason your instructions show that is because all the multiswitches they are typically used with are designed to support at least four outputs. Any time you have more than one receiver, you need separate inputs from the same satellite slot, to cover instances when both odd and even transponders are being requested (from two different receivers) from the same satellite at the same time. Since that won't happen with a single receiver setup, you technically don't need two inputs per slot.

But then the obvious question becomes... why? A 4x4 multiswitch isn't very expensive, is an easy solution, and gives you the option to add more receivers later should the need arise. By the time you build a 2x1 multiswitch yourself, I'd imagine it'd be more than a 4x4 off the shelf. Heck, for that matter, you could buy a Phase III dish with built-in 4x4 multiswitch, and sell your current dish, and end up not spending much at all.

Yeah building one was a bad idea. I thought of the idea because I can only find 2x4 multiswitches locally and would have to order a 4x4. But if a 2x4 will work then I may just go with that. Thanks for the info.

 

[boba]

Yeah building one was a bad idea. I thought of the idea because I can only find 2x4 multiswitches locally and would have to order a 4x4. But if a 2x4 will work then I may just go with that. Thanks for the info.

A 2 X 4 won't replace a 4 X 4 you will still need a 4 X 4 if you want two satellites sent to one receiver.

 

[Darin]

Yes, you can't use an off the shelf 2x4, as they are not multi-sat multiswitches. In YOUR case, you only need 2 inputs, because you only have one output. But a 2x4 multiswitch is not going to handle multi-satellites... the two inputs aren't for two different satellites, they're for odd/even transponders on one satellite. If you were to build your own, you'd only need two inputs for the reasons I stated. But if you buy off the shelf, you will need four inputs, as they are all designed to supply more than one receiver.

 

[sinebar]

Yes, you can't use an off the shelf 2x4, as they are not multi-sat multiswitches. In YOUR case, you only need 2 inputs, because you only have one output. But a 2x4 multiswitch is not going to handle multi-satellites... the two inputs aren't for two different satellites, they're for odd/even transponders on one satellite. If you were to build your own, you'd only need two inputs for the reasons I stated. But if you buy off the shelf, you will need four inputs, as they are all designed to supply more than one receiver.

Can you recomend a good multiswitch for my system? It consist of a 36"x24" Gain Master oval dish with three LNB's (sat A sat B and sat C) and a Hughs directv reciever. Obviously I will still need a 4xN multiswitch.

 

[Darin]

Well, in an attempt to answer your question, I discovered that I lied. You CAN buy a commercial 2x1 multi-sat multiswtich, which would be like what I described if you built one. It can be found here. Probably not a high-demand item, but it is available. You can look here for a selection of multiswitches of various configurations. They don't have any 4x4 switches, but you can always use a 5x4 even if you have no need to integrate OTA into your cabling, or of course, you can always get a 4x8 even though you don't need 8 outputs. I'm not one who gets all excited about buying high-end multiswitches... I think for the most part, they all work as advertised. For cheaper 4x4 multswitches, you can look at ebay. Personally, I'd spend a little extra to get a 4x4 over the 2x1, just because that gives you expandability should you ever get another receiver, or a TiVo.

 

[sinebar]

Well, in an attempt to answer your question, I discovered that I lied. You CAN buy a commercial 2x1 multi-sat multiswtich, which would be like what I described if you built one. It can be found here. Probably not a high-demand item, but it is available. You can look here for a selection of multiswitches of various configurations. They don't have any 4x4 switches, but you can always use a 5x4 even if you have no need to integrate OTA into your cabling, or of course, you can always get a 4x8 even though you don't need 8 outputs. I'm not one who gets all excited about buying high-end multiswitches... I think for the most part, they all work as advertised. For cheaper 4x4 multswitches, you can look at ebay. Personally, I'd spend a little extra to get a 4x4 over the 2x1, just because that gives you expandability should you ever get another receiver, or a TiVo.

With just one reciever do I even need a multiswitch? Could I just connect sat A and sat B to a combiner and then from the combiner to the reciever?

 

[Darin]

No, you have to have a multiswitch. The frequencies from Sat A and Sat B are the same, so they would just interfere with each other. The only reason you can use a combiner with B & C is because DirecTV doesn't have all the transponders on either location, so they are able to do some frequency shifting and combine the two to look like the output from just one satellite. They have ALL the transponders at 101, so there's no space to combine other signals with.

 

[sinebar]

No, you have to have a multiswitch. The frequencies from Sat A and Sat B are the same, so they would just interfere with each other. The only reason you can use a combiner with B & C is because DirecTV doesn't have all the transponders on either location, so they are able to do some frequency shifting and combine the two to look like the output from just one satellite. They have ALL the transponders at 101, so there's no space to combine other signals with.

I'm a bit confused. After reading the FAQ on Solid Signals web site and looking at the diagram of my system it looks like the sat A and sat B LNB needs 18 volts and a 13 volts to switch the LNB between odd or even signals. If I have multi sat multiswitch with a single sat A and sat B input then how does the reciever send both the 13 and 18 volt to select odd or even? Sorry for my ignorance.

 

[Darin]

Only half of the channels from a satellite slot can be transmitted over the cable at one time (disounting expensive stacking solutions). They are split up into odd and even transponders. If you are tuned to a channel that happens to be on an even transponder, your receiver sends (either 13v or 18v, can't remember which is which). If it needs an odd transponder, it sends the other voltage. That is how your receiver communicates to the LNB which set of transponders to send down the cable: odd or even. That is why multiswitches are needed with multi-receiver systems: a dual output LNB is used (one output always sending odd, the other always sending even), and the multiswitch connects the receiver up to the appropriate LNB output, depending on whether it's sending 13v or 18v.

In a multi-satellite system, there is an additional 22khz tone sent up from the receiver if the channel you are tuned to must come from either sat B or C. The presence or absence of 22khz, along with either 13v or 18v, together determine which of the four LNB inputs the receiver is connected to.

The short answer is, it doesn't NEED to send both 13v and 18v at the same time, because with a single receiver, you can't be tuned to more than one channel at a time. Whichever channel you are tuned to will be EITHER on an odd transponder, or an even one.

 

[sinebar]

Only half of the channels from a satellite slot can be transmitted over the cable at one time (disounting expensive stacking solutions). They are split up into odd and even transponders. If you are tuned to a channel that happens to be on an even transponder, your receiver sends (either 13v or 18v, can't remember which is which). If it needs an odd transponder, it sends the other voltage. That is how your receiver communicates to the LNB which set of transponders to send down the cable: odd or even. That is why multiswitches are needed with multi-receiver systems: a dual output LNB is used (one output always sending odd, the other always sending even), and the multiswitch connects the receiver up to the appropriate LNB output, depending on whether it's sending 13v or 18v.

In a multi-satellite system, there is an additional 22khz tone sent up from the receiver if the channel you are tuned to must come from either sat B or C. The presence or absence of 22khz, along with either 13v or 18v, together determine which of the four LNB inputs the receiver is connected to.

The short answer is, it doesn't NEED to send both 13v and 18v at the same time, because with a single receiver, you can't be tuned to more than one channel at a time. Whichever channel you are tuned to will be EITHER on an odd transponder, or an even one.

So a 2x1 multi-sat multiswtich can output 13 or 18 volts from sat A and 13 or
18 volts from sat B? Not simaltaneous but either or. Also my LNB's have two inputs so can each input except 13 or 18 volts? Because only one could input could be used with the 2x1 switch.

 

[Darin]

Yes, the multiswitch only gives the receiver what it's asking for (either odd or even transponders, from either sat A, or sat B/C). That's all it CAN send to the receiver, because that's all that "fits" onto the cable in the DirecTV scheme. Most LNBs today do have two outputs, and both of those outputs can accept 13v or 18v. If you have a single-sat set-up, and have two receivers, you don't need a multiswitch because each receiver can be hooked directly up to its own output on the LNB. Each LNB port will send either odd or even transponders, depending on what the receiver that's hooked up to it asks for (via 13v or 18v). When a multiswitch with more than one output is used, both outputs from each LNB get used... for each LNB, one output will get dedicated to odd transponders, and one for even. The multiswitch always sends 13v to one input from an LNB, and 18v to the other. But in your case, since you only need one output: in the case of a single output multiswitch, there is never a need for odd & even transponders at the same time, so only one output from each LNB is needed. The multiswitch will send EITHER 13v or 18v, depending on what the receiver is asking for. Therefore, one output from each LNB wil be unused. In fact, if you ever did add a second receiver, but only had a 2x1 multiswitch, AND if you didn't need sat B/C on the second receiver, you could connect the 2nd receiver directly up to the second (unused) output on the 101 LNB.

 

[sinebar]

Yes, the multiswitch only gives the receiver what it's asking for (either odd or even transponders, from either sat A, or sat B/C). That's all it CAN send to the receiver, because that's all that "fits" onto the cable in the DirecTV scheme. Most LNBs today do have two outputs, and both of those outputs can accept 13v or 18v. If you have a single-sat set-up, and have two receivers, you don't need a multiswitch because each receiver can be hooked directly up to its own output on the LNB. Each LNB port will send either odd or even transponders, depending on what the receiver that's hooked up to it asks for (via 13v or 18v). When a multiswitch with more than one output is used, both outputs from each LNB get used... for each LNB, one output will get dedicated to odd transponders, and one for even. The multiswitch always sends 13v to one input from an LNB, and 18v to the other. But in your case, since you only need one output: in the case of a single output multiswitch, there is never a need for odd & even transponders at the same time, so only one output from each LNB is needed. The multiswitch will send EITHER 13v or 18v, depending on what the receiver is asking for. Therefore, one output from each LNB wil be unused. In fact, if you ever did add a second receiver, but only had a 2x1 multiswitch, AND if you didn't need sat B/C on the second receiver, you could connect the 2nd receiver directly up to the second (unused) output on the 101 LNB.

Thanks for all the information Darin. I think I understand enough now to make an informed decision about multiswitches. Before I didn't realize that my sat A and sat B LNB's were dual LNB's so the two cable connectors on them makes more sense now. With only one reciever I only need one LNB each for 119 and 101.