Directv LNB to fiber

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woodinator

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Aug 4, 2010
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Southern NH
Hello All,

I have a tough problem. I need to run fiber to a Directv Dish. I have heard of solutions that allow you to where you put a RX and a TX on each leg of the LNB. In my case its a slim dish. 4 LNB's. These solutions are $6k+. Is there a way that I can somehow convert the 4 outputs from the dish into a single output like with an SWM-8 then convert it back again and use it as normal?

If not, can anyone think of a more cost effective way to do this? Just an FYI, we're powering 6 Sat receivers.

Thanks for your help!
 
Last edited:
Thanks jd! Yea, I mistakenly posted it over on the Dish side, and I couldn't figure out how to delete it.

If I power the SWM dish with a 21 volt PS, and transmit the signal from the dish over fiber (I'd use a 250MHz to 2200Mhz Fiber Transmitter/Receiver), is it one way communication from the dish to the SWM Switch? Or does the switch need to talk back to the dish for any reason? If its only one way traffic, this solution should work, and I could put the dish 1000' from the home if needed. Right?
 
I don't know what a TX is.

The SWM system sends a return signal from each receiver to the SWM LNB that is at 2.3 MHz. You'd have to have two way fiber communication and it would have to be diplexed somehow.

Why does this have to be fiber? I've distributed stacked, 950 to 2025 MHz signals over 1,000 feet using RG-11. While you wont have as many amplifier options available for SWM, you could surely run hardline cable (.500 or larger) for a lot less than a fiber link costs, and you'd be able to troubleshoot it if anything ever went wrong with it. If you are willing t use RG-11 or hardline, then call Sonora Design and tell them the length you are negotiating and they will be able to make a hardware recommendation using their products.
 
I don't know what a TX is.

The SWM system sends a return signal from each receiver to the SWM LNB that is at 2.3 MHz. You'd have to have two way fiber communication and it would have to be diplexed somehow.

Why does this have to be fiber? I've distributed stacked, 950 to 2025 MHz signals over 1,000 feet using RG-11. While you wont have as many amplifier options available for SWM, you could surely run hardline cable (.500 or larger) for a lot less than a fiber link costs, and you'd be able to troubleshoot it if anything ever went wrong with it. If you are willing t use RG-11 or hardline, then call Sonora Design and tell them the length you are negotiating and they will be able to make a hardware recommendation using their products.

TX = Transmit
RX = Receive

From what I know.
 
Correct TX=Transmit RX=Receive. AntAltMike, This is a requirement from my customer to completely electrically disconnect anything from the outside to the building. No copper can enter. So the only way I know to do it is Fiber. I am definitely open to other ways.

I've explained how well surge suppressors work and that we've used them 100's of times in the past, but no go. They don't mind paying the money so, we're going through this pain.

The big question I need to have a definitive answer on is this:

Does the 2Mhz signal have to be bi-directional. I'm getting different answers on this one. I know the Sat. Data is one way. Once I clear that up, I'll know what the requirements are and can try to come up with a solution.

Many Many thanks for your input! Its a huge help!
 
DirecTV uses over 5GHz of bandwidth, broadcast from multiple satellites operating at different frequencies. You can't fit them all into one fiber. Their "old" system, with four-output LNBs, breaks them into four bands of 250 to 2150 Mhz. From there, a customer could either connect a single receiver to one of those ports, which would send control signal information in the form of DC voltage (13 volts or 18), simple tone frequency (22 KHz, either off or on) or DiSEqC data ( primitive, relatively low speed pulses formed with 22 KHz signals being turned off and on). One limitation of such a scheme is that one coax (or fiber) connection could only support one tuner, because two tuners on the same coax could only select from the roughly one fourt of the DiercTV programming that was on the coax at one time.

A couple of years ago, DirecTV released its "SWM" system, SWM stands for single wire multiswitch. The SWM system uses the technology of "agile stacking". The receiver sends a 2.3 MHz control signal to the SWM device, telling it which satellite and transponder it desires to receive. The SWM module then matrixes the signals from the correct satellite into a tuner, which selects the desired transponder and frequency-shifts it to SWM frequency #1, which I think is around 980 MHz. When the next receiver sends a signal upstream, the SWM module does the same thing and puts out the second desired transponder at around 1080 MHz. The SWM system does that with up to eight transponders. I believe it also sends a ninth, downstream signal with programming and control information at a frequency of close to 1900 MHz, but I've never looked into the technical particulars of it.

If you are using the terms Rx and Tx to refer to fiber transmitters and receivers that you intend to use, then those terms are ordinarily used to describe one-way devices. While your fiber itself can carry signals in two directions, I would not ordinarily expect an RF-to-optical converter to do that.

You can get by without two way communication if you have four fiber connections and four transmitters and four receivers running from the dish to the building, but that would also entail buying four transmitters and receivers (plus a fifth of each, because you will be the person servicing this system, and you will sometimes need to shot-gun swap in replacements to identify a malfunctioning unit). And in any fiber configuration, you will still have to power the SWM LNB with 18 to 20 volts. How can you do that without a copper connection from your building?

The cable companies send upstream signals for two-way communications with their boxes and also for internet upstream, and these systems commonly use upstream frequencies from 10 to 47 MHz, so there must already be some off-the shelf hardware for upstream communications over fiber, but that equipment may not work at 2.3 MHz, and multiplexing the upstream with the downstream may even require computer controlled switching at junction nodes. Toner Communications is one of the few CATV hardware dealers that sells both to large cable companies and to independent installers, so they may be able to tell you if they have any fiber solution that can send 250-2150 MHz DBS signal downstream and simultaneously carry 2.3 MHz upstream, but even then, if the 2.3 MHz SWM signal is two-way (which I am inclined to doubt), then products that work for cable TV sub band return would not work for SWM sub band communication.

I've never had reason to consider whether the 2.3 MHz signal is one way or two way, because the only SWM-compatible amplifiers presently available that I'm aware of use passive return paths because there is so much less coax path loss at 2.3MHz than there is at L-band frequencies. Someone at Sonora could tell you for sure. I wouldn't trust answers from anyone else - even from large MDU companies - because people hired to design and install even large L-Band systems are almost never engineers. They are told by a manufacturer that something will "work" in their application if installed a certain way, they try it, and then if it works reliably they continue to use it, but their jobs don't require understanding how the hardware actually does what it does.

This plan isn't going to fly at any price. Even if you can pull it off for $20,000, you still won't be remotely qualified to service it. You will approach each service call as a neophyte, since you won;t be acquiring any diagnostic expertise from any other systems you maintain, and any telephone support you can get from hardware manufacturers may be inadequate.

Remember, the leading edge is the bleeding edge, and if you buy and install something for $10,000 or more and the customer reports that it is intermittently failing them, how do you go about diagnosing and remedying the problem?

Realistically, the dish has to be connected to the building using conventional metal coax, and your opinion of the adequacy of surge suppressors carries insufficient weight with management, as it should. What you need is to get someone on his "team" to tell him that an exterior coax does not present a technical liability to the other equipment. You need to find out how he came to conclude or be concerned that the coax cable introduces a risk, and work back from there.
 
AntAltMike, First of all, thanks for the great response. Yea, its a bummer I can't get them to just go with good lightning suppression and grounding. I know it works, but they are convinced that having it run over fiber and electrically separated is the way to go. They unfortunately lost lots of equipment from another lightning strike....

I have contacted Sonora. Thanks for the lead. I'll see what they have to say. Even if I have to do a oneway connection for the TV signal and a bi-directional for the control channel it still might work. I did talk to Toner yesterday before I posted and they didn't know of a way, so they suggested the slim dish with 4 outputs and put a transmitter and receiver on each one. There is a device that polarizes the LNB's which works well. For the SWM system, I understand that all you have to do is inject 21 volts in the line to the dish and that energizes the LNB's and the SWM Switch takes care of the traffic handling. I'm hoping that Sonora can confirm or deny that.

Thanks again for your great response. It helped quite a bit!
 
It would cost you a lot less to put a 4' dish indoors, behind glass or plexi, and see how much signal it can develop.

I don't see what you mean by having "the SWM Switch take care of the traffic handling". It gets its instructions from the signals sent from each receiver up the coax at 2.3 MHz.

There was another company using the name Foxcom that was committed to fiber distribution of RF signal a few years ago. If they are still around, they may be able to help you.

I can't imagine why the 2.3 MHz signal would be two-way, because the system already has downstream communication on transponder #9.
 
If you saw this house, I guarantee that there will not be a 4' dish in there LOL! If the property line was farther away, it would be there.

What I meant by the SWM handling the traffic is that it is the central point. Yes the receivers talk back and forth to it, but I don't think that the switch needs to talk to the dish.

I looked at foxcom and they are still around. They are part of OnePath now. They have some great fiber products. Much more than we need.

I agree on the 2.3 being oneway. I'll be interested to hear what Sonora says.

Again thanks!
 
Directv over Fiber

Woodinator........if there issue is copper from dish to building due to electrical hazards then have them build a shed to put the fiber transmitters. Once in the building as you know more than four receivers require a switch. You can use SWM at this point the only return path is the control signal from receiver to switch not dish. At some point copper has to be introduced even if at a minimal level. Hope this helps
 
Directv over Fiber

Woodinator feel free to call me.....we have just completed several fiber distribution systems for HP here in California and have learned our lessons.

Best of luck. 916-622-7291
 
Thanks Appleboy! That would be great. I'll probably have one of our guys give you a call to discuss. It would be great to not have to re-invent the wheel.

Thanks again!
 
Hello All,

I have a tough problem. I need to run fiber to a Directv Dish. I have heard of solutions that allow you to where you put a RX and a TX on each leg of the LNB. In my case its a slim dish. 4 LNB's. These solutions are $6k+. Is there a way that I can somehow convert the 4 outputs from the dish into a single output like with an SWM-8 then convert it back again and use it as normal?

If not, can anyone think of a more cost effective way to do this? Just an FYI, we're powering 6 Sat receivers.

Thanks for your help!

There is a company called Optical Zonu that just released a DirecTV SWM compatible fiber optic multiswitch extender. Basically the system uses a pair of fiber transmitters and receivers to create a bi-directional link over a single fiber. The SWM side unit transmits the L-Band agile stacked downlink to the IRD, and the the remote end transmits the 2 MHz control signal back to the SWM. Right now Optical Zonu is the only company that has this solution. The alternate approach, as mentioned, is to take the downlink from every LNB and transmit it over fiber to the multiswitch location. There are many downsides to this approach. Each LNB requires its own dedicated optical transmitter and receiver. If these are modular, then each will most likely require its own fiber. There are chassis based solutions that use CWDM to combine all the transmitters outputs to a single fiber, but most of these solutions are rackmount and cannot be installed in an outdoor location. Another downside is most optical transmitters will not provide the polarity locking voltage or tone needed by the LNB. So you have to add even more equipment. If you really need a fiber link for satellite TV, I suggest contacting Optical Zonu. They are the only company that can provide fiber links for every segment of a cable TV system. They have IP-67 rated outdoor enclosures for LNB downlink transmitters, and they are the only company that has a commercially available DirecTV SWM over fiber extender.
 
The question is how many feet do you want to extend. With the correct amplifiers, you can extend a directv signal thousands of feet.

I think an amp is required every 150 feet, or 6 floors in a commercial building.

The whole issue is powering everything along the way.
 
This thread is 5 years old, I hope he got this resolved a long time ago ....

All this for lightning protection ?
Hmm, lightning can't travel over Fiber ?
 
This is an emerging field, as up until recently it has been economically unfeasible to utilize these types of fiber optic systems for satellite TV installations. While it is still expensive, the price has dropped to the point where it is more attractive to a growing audience of installers and integrators. While it is possible to send satellite TV signals longer distances over coax, it difficult. You need to install a powered amplifier every few hundred feet, low loss coax is more expensive than fiber cable, and you do not get lightning protection. Singlemode fiber optic cable consists of non conductive polymer buffer and jacket coating a tiny core made of pure borosilicate glass fiber. Nothing in it comes close to conducting electricity. For this reason it is often used to provide electrical isolation and protection against lightning strikes. SWM over fiber systems are brand new on the market, and offer the lowest cost solution yet for sending satellite TV over fiber. I've seen several other companies make equipment for the LNB downlink, but Optical Zonu is the first manufacturer I've seen that is offering a bi-directional SWM transceiver.
 
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