Yes, a multi-switch, couldn't think of the name. I have a Channel Vision catalog right in front of me and they actually look like they are working with Spaun since the Spaun units are in the Channel Vision catalog.
www.channelvision.com
I had asked a friend about the need for multiswitches and how sat dishes worked years ago and am pretty sure that I am correct for why the multiswitch is needed... so that the dual LNB modules can pick up both horizontally and vertically transmitted broadcasts and send them simutaneously to the multi-switch. Then the multi-switch manages which signal is sent down a cable to a DSS receiver. Basically, the DSS receiver says "I need this channel which is on a horizontally broadcast frequency" - The mulit-switch recognizes the request, and passes on data from the correct LNB.
Hang on, let me google it.... (2 minutes later)....
This is the site:
http://www.tivocommunity.com/tivo-vb/showthread.php?s=&threadid=55509
and this is a great excerpt, long but great info:
1. What is an LNB? LNB stands for "Low Noise Block Converter" (thanks toolbox ). It is the part of your Satellite dish that hangs off of the arm and looks like a flashlight. It is what captures the digital signal from the satellite.
2. How does an LNB work? There are 32 transponders on the 101 degree satellite (main satellite) that send channels. They are numbered 1-32. Each transponder sends a group of channels. An LNB on a satellite dish can look at either odd or even transponders at any given time. It cannot see both at the same time. If you change the channel to one that is on an odd transponder, then the LNB switches to look at the odd...if you change to a channel on an even transponder, then the LNB switches to look at the even.
3. How does the LNB know which side (even or odd transponders) to look at? This is done by voltage changes that your DirectTV receiver sends.
4. What is a Dual LNB? A Dual LNB is just two LNB's...each connection can operate independently of each other so you can have two receivers each looking at different stations on different transponders. They both look at the same satellite (101 Degree satellite). A single LNB only has one coax connection and cannot be used with more than 1 DirectTV receiver.
5. What is the difference between the "Round" 18" dishes and the "Elliptical" 18"x24" dishes? The 18" dish had a Dual LNB that looks at one satellite. The satellite is positioned at 101 degrees and sends all the main programming that is offered in the DirectTV packages. The 18x24" dish has TWO Dual LNBs and is set up to see two satellites...the 101 degree and the 119. The 119 degree satellite sends additional programming such as the NASA channel, ParaTodos Spanish programming, other foreign language programming and HDTV channels. You could also use two Round 18" dishes, one pointed at the 101 degree satellite and the other pointed at the 119 satellite to do the same as the Elliptical dish. You would connect the four cables from the two dishes to a multiswitch explained below.
6. Can I use a splitter to add more receivers or add dual Tuners to my DirectTiVo? NO....this is where multiswitches come into play. You cannot use regular splitters. From the explaination of LNBs above, you should understand that if I split an LNB with a regular splitter, then I will have two receivers using the same LNB and fighting over looking at odd or even transponders. One or both receivers will only be able to see half of the channels.
7. What is a multiswitch? A multiswitch takes the input from both of the LNB's (both cables from a dual LNB dish HAVE to be connected to the multiswitch)...it then locks one of the LNB's to always look at the even transponders and the other LNB to always look at the odd transponders. This is why a multiswitch only works with Dual LNBs and not single LNB's. The switch then has multiple outputs to receivers (4,8,etc). When you connect the receiver to the multiswitch, the switch determines which of the two LNB's the receiver needs to look at depending if it needs to view odd or even transponders. When you change the channel, the switch then swaps your connection to the other LNB when needed. With a multiswitch, the LNB's never change which side they are looking at.
8. What about multiswitches with Elliptical dishes? If you have the oval dish with two "dual LNBs" (4 cables), each of the Dual LNB's look at different satellites (101 degree and 119 degree satellites). A multiswitch is needed to see the second satellite. A multiswitch comes with the dish and is usually have 4 outputs. Multiswitches for elliptical dishes need to have 4 inputs so it can switch between the 4 LNBs rather than the 2 in the explaination in #7 above.
9. If my receiver sends voltage changes to switch between odd and even transponders on the 101 satellite, how does it tell the multiswitch that it wants to see the 119 satellite? The receiver sends a 22khz tone over the cable along with the voltage change so it tells the multiswitch that it wants either odd or even transponders by the voltage and that it wants the 119 by sending the tone.
10. What is the 2x4, 2x8, 3x4, 3x8, 4x4, 4x8, 5x4 & 5x8 designations mean when referring to a multiswitch? The first number in the number of inputs from the dish (or antenna) the switch has. The second number is the number of outputs the switch has.
A 5x8 multiswitch would handle 4 DTV inputs (Two Dual LNBs looking at the two satellites) and a Cable TV or antenna input if you wanted. It would have 8 outputs that could go to 8 DirectTV receivers, 4 Dual Tuner DirectTivos or any combo in between.
