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Help Moving My Dish

Discussion in 'General DISH™ Discussion' started by sunspot, May 7, 2005.

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  1. May 7, 2005 #1 of 16
    sunspot

    sunspot Cool Member

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    I live next to a south facing forest and the only spot I have for an eave mount has now grown in. I did a new site survey and the only place I have on the house is a roof mount at the roof peak. The other choice is a ground pole 160' away from the house. What would the experts here have to say? Roof or ground?
    Another pointing question is the azimuth. The dish pointing menu said 223° but as I have my setup, the LNB arm is more towards 200-205°. I have a Dish 500 dual. Is the menu only a rough guide?
     
  2. May 7, 2005 #2 of 16
    larrystotler

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    No, your compass is probably off. Most are off at least 9 degree. As for the best place, go for the most unobstructed Line of Sight you can get.
     
  3. May 7, 2005 #3 of 16
    sunspot

    sunspot Cool Member

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    Both sites are unobstructed. I have heard that the roof mounts may not be good for the roof and long cable runs are not so hot either. Which choice is the lesser of the evils? :confused:
     
  4. May 8, 2005 #4 of 16
    SimpleSimon

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    Roof mount is better than 160'. Just do it right.

    With 160' just to get back to the house, you're likely to exceed the maximum limit for DishPro - and it's out of the question for Legacy.

    BTW, do you REALLY have a "Dish 500 Dual"? I doubt it.
     
  5. May 8, 2005 #5 of 16
    Mike500

    Mike500 Hall Of Fame

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    The roof mount would be my only option. If the attic is open and reachable below the mounting, that would be much better.


    I've done a lot of high end, totally in wall fish installs this way. Cable entrances are best made through and under a ridge vent, under the end gable eave, or through a correctly installed and flashed weatherhead.

    Mounting on a pitched roof is actually preferred, if done right. Never mount on a flat roof or within 2 feet of a valley. The strongest mounting point is at the corner of the house right at the convergence of the wall corners and the rafters. The rafters are easy to find there. Movement will never be a problem.

    Never "glue" the dish foor to the roof with silicone or roofing cement, like it advised in the self install manuals. Don't predrill holes for the mount, and don't use 1/4" or 5/16" lag screws. Use 1/4" (#14)x 3 inch hex head drive hardened sheet metal screws. If you can't find them at hardware stores, Home Depot sells small packages under the Simpson Strong Tie brand. They will about never break like lag screws. Drive one, without predrilling through the center round hole through the shingles into the rafter. Plumb the pole in the up/down swing direction. Tap the foot in the corner until the pole is plumb in the opposite 90 degree axis. Drive the second three inch screw in the crescent slotted center foot axis hole. Drive four 1/4(#14)x1-1/2" long hex head hardened sheet metal screws into the corners, just enough, since these can easily strip out as they are going through shingles or light OSB or plywood flashing.

    Actually on a pitched roof, no sealing is necessary. The heat from power driving the screws, without predrilling melts and displaces the asphalt from the shingles around the screw and rehardens. Just to satisfy the customer, I might put some sealant on the screw heads. Thick layers of tar makes for an ugly install and does no good.

    When it comes to dish removal time, remove the screws. You are left with six less than 1/4" diameter holes that are easily sealed. The shingles do not come off with the mounting foot, as if it was "glued" to the roof. A dish foot "glued" to the roof will not keep the dish on the roof during a storm. It just takes the shingles off with it. Fastening the dish to the roof means screwing into the roof.

    How to install a roof cable entrance.

    I'd go out and get a piece of 1-1/4" PVC conduit, a couple of same size 2 hole clamps, a service entrance head, and a vent flashing.

    Go into the attic, using a 1-3/4" hole saw. Start it flat with the sheathing right next to a rafter. As it it cutting part way through, tilt the hole saw, until it is plumb. Outside; using a large putty knife or a dry wall taping knife, carefully lift the shingles around the hole. Remove any roofing nails at least a foot radius around the hole. Place the flashing over the hole, and cut a circular "U" out to match the flashing raised area plus 1 inch all around, starting at or below the center of the hole. Slide the flashing under the shingles, matching the raise area. Shove an 18 inch long piece of pvc conduit through the flashing and the hole in the sheathing. Inside the attic, strap the conduit to the rafter. Outside, nail down the bottom corners of the flashing and replace any nails taken out that held the shingles. Glue on the cable entrance weatherhead.

    This is the correct and truly professional method of doing this.
     
  6. May 8, 2005 #6 of 16
    Jerry G

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    Does the Dish calculation take magnetic declination into account for your location (I doubt it does)?
     
  7. May 8, 2005 #7 of 16
    sunspot

    sunspot Cool Member

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    Apr 21, 2004
    SimpleSimon
    You are correct. I checked my records. I have a twin.

    Mike500.
    I was leaning towards the roof mount. You clinched it for me. Thanks for the advice on the installation. I was going to use lag screws and silicon the heck out of it.I'm off to Home Depot for supplies.
    Thanks to all for the answers.
     
  8. May 8, 2005 #8 of 16
    AllieVi

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    You probably could do the ground mount if you used RG-11 cable instead of RG-6. The numbers I've seen show that it should be able to go the 160' without a problem, but it's more expensive (the cable itself and the connectors). Check out some of the coaxial cable suppliers for prices.

    Before you do anything, try running an RG-6 line on the ground and see if it works.

    I'm an advocate of ground-mounting when possible, but the cost difference in your case might be high if you'd have to use RG-11.
     
  9. May 8, 2005 #9 of 16
    Mike500

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    There is something called a Tinnerman "Palnut" that allows you to tighten it on the end of a 1/4"x14 sheet metal threaded screw. The Palnut (designed in World War II for the aircraft industry) is made of hardened spring steel and has one slot on it that allows it to match the threads perfectly. I've seen these in the threaded fastener "Pick-a-Nut" blue drawers at Lowes. Be sure you have the ones with the single radial slot, not the ones with two. I get these in quantity for my installs, but you can get them at Lowes. They are designated 1/4x20 but will fit on the threaded sheet metal screws just as well. Back this up with a 1/4x1" diameter fender washer, and you'd have a very strong hold onto the roof deck.

    I've also done my share of ground mounts, but most of the installers who I've seen do not use the requisite "flooded" underground cable.
     
  10. Mike500

    Mike500 Hall Of Fame

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    http://www.dbsforums.com/images/map.gif

    Actually, it depends on where you live. The agonic line or the line with no magnetic difference between true and magnetic north runs down from Western Michigan through Central Alabama. Anything east of this line has positive declination and anything west has negative declination. Just find your location closest to the line with the number on the map. Subtract for the west. Add for the east.
     
  11. sunspot

    sunspot Cool Member

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    Apr 21, 2004
    The menu calculation is ZIP code driven, so I'd hope I don't have to figure in magnetic pole deviation from true north. Anyway, I hope so. :eek2:

    I think I'd like to stay with a high grade RG-6 (Quad Shield, 18AWG solid copper center, swept tested) due to the cable cost and the cost of re-tooling and new connectors.
     
  12. sunspot

    sunspot Cool Member

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    Apr 21, 2004
    Hooray. I live in Central Alabama. :D
     
  13. Mike500

    Mike500 Hall Of Fame

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    Any good quality rg6 is good. I've never had any brand name like Commscope, Belden, Amphenol Times Fiber, or even General Cable (Carol) failed to work with DishPro equipment. Just because it has not been swept to 3000 Mhz, does not mean that it will not handle it.

    Solid copper cable is more physically fragile than Copperweld (the original tradmarked and patented process for copper plated steel). Most all commercial cable companies use the copper plated steel center conductor, since it maintains it's rf impedence charactieristics much better than solid copper. Basically it takes more abuse.

    In the early days of telephony and telegraphy, both Western Electric and Western Electric made hard drawn copper. They did for cable tv also, but found it was not necessary.

    Copper is only a factor for long runs due to voltage drop in lnb switching. The video signal actually rides on the surface. This is referred to as the "skin effect."

    I have a supply of Monster Cable brand solid copper conductor and solid copper braid rg6. Nobody wants to pay the cost. It is not necessary.
     
  14. sunspot

    sunspot Cool Member

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    Apr 21, 2004
    I was blank for about ten minutes. :( I have not seen one of these for a fair number of years. Great tip.

    I'm using Monster brand quad but it has an aluminum braid. It was less then $0.20 ft. I have not seen a copper braid coax in a long time. BTW, I use a EX6XL connector by PPC squeezed by a Sargent 8800 US. Are they good ones?
     
  15. AllieVi

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    Installation companies aren't generally kind to cables. For that reason, I can understand why they use the plated steel variety. They often have to pull long lengths through conduit around a couple sweeps, so the extra strength of steel is good since it takes all the pulling abuse (copper could stretch and change the properties). The extra initial cost is a big issue, too. But for a residential installation by a homeowner who will use kid gloves, I'd go for the solid copper (and I did).

    I understand the skin effect and the fact that the plated cable works, but I prefer the copper center.
     
  16. Mike500

    Mike500 Hall Of Fame

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    The PPC EXXLs are really good connectors, as are their standard EX series, Snap-N-Seal, and other brands.

    The most important thing is proper preparation and installation. I've seen many so called professionals, who install them wrong. DBS needs more careful installation than just cable TV or OTA, since the connection must past switching voltage. Here is the correct way to install coaxial connectors;


    Stripping and installing connectors on Coax


    Careful preparation of the cable end is very very important, especially with quad shielded cable. Sloppy preparation will result in failure to set the compression connector properly.


    1. Strip off the outer jacket of the cable and a portion of the center conductor as instructed by the document provided with the stripper.

    2. On quad shield coax, carefully fold back the outer shielding wires against the outer jacket of the cable evenly, exposing the inner shielding wires.

    3. On both tri-shield and quad shielded coax, carefully cut away the outer foil shielding layer, and remove it to exposed the inner shielding wires. This will not need to be done on regular coax.

    4. Carefully and evenly fold back the inner shielding wires evenly against the outer jacket.

    6. Place the connector on the stripped coax, making sure that the center insulator enters the inner tube of the connector with "only" light pressure. If it requires heavy force initially, the insulator is not entering the tube correctly. The connector is fully inserted when the center connector is level with the end of the connector, when looking inside the nut.

    7. Crimp the connector with the proper hex crimper or compress the connector on the cable with the proper compression tool.


    Reasons why the shield wires must remain intact and must be folded over the outer jacket

    A straight cut of the outer jacket and the shield wire layer(s) down to the center conductor insulator will not allow full contact and retention of the outer shield. The shielded wires must be folded back over the jacket. Not doing so means that the connector is just slid over the shield wires and outer jacket and retention of the shield wires are held by friction, not by tightly held tension. Tightly clamping the ends of the shield wires prevents degrading the electrical contact of the shield wires, which serves as one leg of the voltage switching circuit for the multiswitch or lnb of 15-18 volts. If you are passing only a RF signal, it is not a problem, and might not be a problem for short coax runs. But on long runs, any minor bit of corrosion or separation of the barrel from the shield wires might lead to failure and a resultant voltage drop over time. This will manifest itself in the lost of the even transponders in the signal.

    The industry standard is the 1/4"x1/4" strip on the coax. If the center insulator is below the center hole in the barrel, the coax has not been fully seated. Ideally, it should sit about 1/16" or 2mm out of the hole. If you a using a compression tool that applies pressure to the inside of the connector, the plunger will force the center conductor almost flush. Over time it might return to the 2mm protrusion. This protrusion is ideal in that it eliminates the "air" gap between the center conductor insulator and the female socket port. The "air" gap increases the chances of water vapor entry and corrosion. If you look at an F81 female port carefully, you will notice that it is recessed about 1/32" or 1mm.

    So, folding back the shield wires enhances the electrical contact surface between the shield and the barrel of the connector. It also increases the connectors resistance to pull off. The bent over shield wires clamped by any type of connector prevents "pull off" and ensures the integrety of the connection for passage of both the RF signal, and more importantly, with dbs, the free conveyance of the lnb switching current.
     
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