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  • #1

    Adding SWM to large office bldg

    First of all, we're self-maintained & not really looking to make a change...

    I have a 550,000 sq ft office complex consisting of 9 floors + basement. The bldg. is a bit unusual, 640 feet long and 85 feet wide. I have 4 wiring closets per floor (40 total). We're presently feeding a 24-channel Blonder-Tongue head-end with legacy D* Hughes GAEBO receivers and B/T channel modulators & combiner to derive a "mini" 24 channel CATV system. This system works well and needs to remain in service (for the time being at least)

    However, we're beginning to get inquiries about HD. The SWM concept looks like the answer, provided we can offer some minimal distribution capabilities in each of the 40 wiring closets. Two verticals are 120 feet apart at each end of the bldg with 240 feet between them. To explain, call them Risers A, B, C, and D. A&B are 120 feet apart. B&C are 240 feet apart, C&D are 120 feet apart. Horizontal drops (RG6/Plenum) vary from 80 to 200' between the wiring closet and the TV. Most are around 120'.

    Our current in-house backbone system uses Blonder-Tongue BIDA 450-50 trunk amps (4 total) in the 2nd floor riser rooms to push a +55 signal 7 floors up and 2 floors down via RG11-quad with appropriately-graduated directional couplers feeding an 8-way tap in each wiring closet. Obviously not all ports are hooked up. Guessing, there's currently a total of around 80 NTSC televisions hooked up (and most of this will remain connected to the current system).

    With the above cable length logistics in mind, can we do something similar with SWM and individual discreet IRDs? I need the ability to make HD along with something like an H20/H21 receiver "available" to anyone anywhere in the building, but without "gilding the lilly" or breaking the bank with an overkill of infrastructure that's going to sit mostly un/under-utilized. I'm thinking we may have as few as 10 people interested (initially) but they're scattered all over this building (12 acres under roof). Going forward this will grow, but not exponentially. We need to start small and grow the infrastructure too, if possible.

    My thinking is we're going to need an AU9 dish and lock polarities then amp, split and distribute all 4 dish leads to each of the 4 vertical risers before hitting any of the SWMs. Am I on the right track here? I don't plan to have a SWM in every riser room, but perhaps every 3rd floor, say on the 2nd, 5th and 8th or can I get away with putting them just on the 3rd and 7th floors? I'd like to "plan for" SWMs (or taps) on these floors but without initially equipping them, just equip today where we need to, but cable it out to provide for flexibility to add on reasonably short notice (ie, a week ahead).

    What amplifier (make/model) are others using for sigs coming from the dish? Does it need to be bi-directional (any signaling going back towards the dish?)

    Anyone have some drawings or designs to do this? I need to have some idea of the material needed so we can work up some budgetary numbers to take to mgmt., but again remembering that we want to do this in-house (ourselves) and not pay someone their markup & labor rates to build it for us.....I don't have that kind of budget. We built our own catv system, shouldn't we be able to do this as well?

    Pointers appreciated.
    Last edited by Tri-Shield; 01-14-2009, 12:36 PM.
    Tags: None
  • #2
    Originally posted by Tri-Shield View Post
    My thinking is we're going to need an AU9 dish and lock polarities then amp, split and distribute all 4 dish leads to each of the 4 vertical risers before hitting any of the SWMs. Am I on the right track here? I don't plan to have a SWM in every riser room, but perhaps every 3rd floor, say on the 2nd, 5th and 8th or can I get away with putting them just on the 3rd and 7th floors? I'd like to "plan for" SWMs (or taps) on these floors but without initially equipping them, just equip today where we need to, but cable it out to provide for flexibility to add on reasonably short notice (ie, a week ahead).

    What amplifier (make/model) are others using for sigs coming from the dish? Does it need to be bi-directional (any signaling going back towards the dish?)
    Yes, I think you are on the right track. Take a look at this diagram:

    SWM Wiring Diagram

    This diagram shows what you envision: Dish to polarity locker to amp to SWMs.

    In your situation, out of the amp, you'll likely go to a tap and from there into a multi-swm chassis. You can put the taps at appropriate places in the risers, and you will likely have to add an amp every couple hundred feet. There are chassis that hold 2, 4 and 6 SWMs, and as you probably know, each SWM can feed up to 8 tuners.

    The SWM will also pass signal in the terrestrial and SMATV range (54-806 MHz).

    My experience is with the SWM systems and not with the CATV/headend distribution, so I can't help with that part of the equation.

    Comment

    • #3
      Thanks! Yes, I think you and I are on the same page here.

      SWM-8 feeds 8 tuners or 8 DVRs? Think I missed something there. I thought the SWM-8 was dual output and each output could drive an 8-way splitter. Perhaps I mis-read something

      Questions
      • Does the AU9 dish (not ODU) require any reverse signaling or control signals?
      • Is there a reason to use a conventional AU9 dish vs a SWM ODU? I think so, but I need it explained.
      • Why do the splitters after the PI need diode steering? I thought the polarity would already be locked and we wouldn't be passing any DC back thattaway
      • Is there a preferred (or recommended) make/model of amplifier? I'm thinking 14 db spacing on the amps.
      • What is the recommended maximum number of amps in cascade?
      • Is tilt (slope) going to be a factor here? Longest total run looks to be around 600 cable feet from the PI
      • The SWM requires some signalling from the IRD, right? RF/DC or audio?
      • probably more later....
      Last edited by Tri-Shield; 01-14-2009, 02:52 PM.

      Comment

      • #4
        Originally posted by Tri-Shield View Post
        Thanks! Yes, I think you and I are on the same page here.

        SWM-8 feeds 8 tuners or 8 DVRs? Think I missed something there. I thought the SWM-8 was dual output and each output could drive an 8-way splitter. Perhaps I mis-read something
        It's definitely eight tuners, and NOT eight DVRs. It's four DVRs.


        Questions
        • Does the AU9 dish (not ODU) require any reverse signaling or control signals?
        • Not sure what you're asking here; the 5LNB works like the other DIRECTV dishes in this regard.
        • Is there a reason to use a conventional AU9 dish vs a SWM ODU? I think so, but I need it explained.
        You can't expand beyond eight tuners with the SWM ODU, nor can you add other components to the system if you need them, like polarity lockers and amplifiers.
      • Why do the splitters after the PI need diode steering? I thought the polarity would already be locked and we wouldn't be passing any DC back thattaway
      I actually don't believe the SWM splitters are diode steered; the important feature is that they go down to 2mhz.
    • Is there a preferred (or recommended) make/model of amplifier? I'm thinking 14 db spacing on the amps.
      • We only sell one, and it's made by DIRECTV.
    • What is the recommended maximum number of amps in cascade?
      • There isn't a max that I know of. You don't want to over-amplify; it tends to kill the entire system.
    • Is tilt (slope) going to be a factor here? Longest total run looks to be around 600 cable feet from the PI
      • Mostly this is a "try it and see if it works" type of thing. There are no black-and-white specs.
    • The SWM requires some signalling from the IRD, right? RF/DC or audio?
      • It's around 2 mhz.
    • probably more later....

      Comment

      • #5
        Thanks Jeff. This has explained a lot. I've prowled yours' and others' web sites on the topic and found most of what I need. One of your competitors had a diagram of a high-rise bldg that (after chatting w/you) also made a little more sense about the breakdown between floors. With your help I think I may have enough to work up a bill of materials now & present it.

        I don't look for the plan to result in the immediate release of funding, but it will provide a roadmap to follow as we add the necessary pieces to bring the first user online and then project costs to add subsequent users thereafter. Even when complete, I foresee no need for a 6-up rack of SWMs in every closet. I anticipate being able to feed maybe 3 floors from a single wiring closet. Lotsa folks in this bldg, but not many TVs.

        It will be cheap enough to go ahead now and wire for SWM feeder taps in every 3rd closet since we have several thousand feet of RG11 quad plenum & connectors already on hand. With that much in place we can also put a 2 Ghz beacon signal on it, take some measurements and determine the amplifier count and where they need to go.

        I think we'll ask the client to buy the initial SWM-8 for his floor & quadrant. We'll furnish the receivers, since it'll all be under a common subscription it gives better control of what's where. D* used to limit us to 20 IRDs per business account. Do you or anyone know if that's still the case?

        Comment

        • #6
          A Few Additional Questions

          Jeff, I've managed to come up with some additional things to ask about. Hope you don't mind.
          • Can the output of the SWM-8 be amplified to provide longer drop capabilities from the SWM (or splitter) than the recommended 250~300 feet?
          • If that answer is 'yes' then what amplifier do I use? It would obviously need bi-directional capability with a 2~5 Mhz back channel, correct?
          • Is an equalizer necessary (or recommended) between the AU9 and the 1st amplifier?
          • Confirm for me the number of downlead cables I need from the AU9. In my thinking I see a need for only 3 (99-101-103). If correct that could reduce some back-room infrastructure costs. What am I missing here? (what's on 110/119 that I would need? Our HD locals are already on Ka)
          • Existing legacy IRDs will need to be replaced, correct?
          • Directional Couplers (taps) with port values 20 db or greater and rated for 2100 Mhz seem hard to source. Where do we get them?

          Thanks!!!
          Last edited by Tri-Shield; 01-15-2009, 10:05 AM.

          Comment

          • #7
            Originally posted by Tri-Shield View Post
            • Is an equalizer necessary (or recommended) between the AU9 and the 1st amplifier?
            No. DIRECTV's specs do not spec out an equalizer, but the DIRECTV amp we carry has dials/pots enabling you turn the amp up or down, and has lights indicating whether the signal is too high/low.

            Originally posted by Tri-Shield View Post
            • If that answer is 'yes' then what amplifier do I use? It would obviously need bi-directional capability with a 2~5 Mhz back channel, correct?
            See above.

            Originally posted by Tri-Shield View Post
            • Confirm for me the number of downlead cables I need from the AU9. In my thinking I see a need for only 3 (99-101-103). If correct that could reduce some back-room infrastructure costs. What am I missing here? (what's on 110/119 that I would need? Our HD locals are already on Ka)
            You need 4 cables. That is the # of inputs on the SWM.

            Originally posted by Tri-Shield View Post
            • Existing legacy IRDs will need to be replaced, correct?
            Correct.

            Originally posted by Tri-Shield View Post
            • Directional Couplers (taps) with port values 20 db or greater and rated for 2100 Mhz seem hard to source. Where do we get them?
            We don't stock them, but can get you taps. We have 2-way (allowing up to two chassis) and 4-way taps (allowing up to 4).

            Comment

            • #8
              Originally posted by WK-Jeff View Post
              No. DIRECTV's specs do not spec out an equalizer, but the DIRECTV amp we carry has dials/pots enabling you turn the amp up or down, and has lights indicating whether the signal is too high/low.
              Think you misunderstood the second question. I was wondering about amplifying for the purpose of extending the range of the stacked output of the SWM-8 to reach a more distant tuner much greater than 200 feet from the Splitter. That answer I've subsequently learned is a qualified 'yes' tho with a competitor's product and therefore most likely unsupported, but still technically doable. (Not that I would but I could - just looking for the "what-If's to cover my backside when a VP needs a connection right now before we can extend the trunk to reach him the right way.) Executives do not deal well with delayed gratification... at least mine don't. Remember, the initial plan is to start small and build the plant piecemeal, extending the reach of the backbone trunk into wiring closets only as needed rather than a complete, cost-is-no-object buildout.

              You need 4 cables. That is the # of inputs on the SWM.
              I see a 3-LNB ODU is offered for only 99/101/103 so I thought (hoped) we could skate by with only 3 cables on the trunk. That's OK. I was just trying to cut where I could. A 4th would mean my total backbone (trunk) would grow to just under 5,000' of RG11.

              We don't stock them, but can get you taps. We have 2-way (allowing up to two chassis) and 4-way taps (allowing up to 4).
              Well I hope you understand that we're on a shoestring budget here and therefore having to literally "shop" each component among vendors we've found. I did not find any "combo" taps, but that might be a way to save some $$ provided they were less than 4X the cost of a single tap.
              • Where can I look to get budgetary numbers?


              Thanks!!!!!
              Last edited by Tri-Shield; 01-15-2009, 05:56 PM.

              Comment

              • #9
                DIRECTV specifically states that nothing other than SWM splitters and (if no chassis is used) a power supply should be between a SWM and an IRD.

                To my knowledge, the 3LNB ODU also has 4 lines down.

                If you want to specify the equipment you want, we can give you pricing. You can do that via email through our contact form. We do not provide specific pricing or quote information on these forums. Most swm pricing is here:

                SWM8 equipment

                For other equipment (taps, DIRECTV-branded polarity locker, DIRECTV amp, 6-SWM chassis), you'd have to email a RFQ and your needs.

                Comment

                • #10
                  Thanks again Jeff!

                  Comment

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