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Long cable - lots of problems - theories welcome

Discussion in 'Other HD Receiver Support Forum (811, 921, 942)' started by FrequentFlyer, Jan 30, 2005.

  1. FrequentFlyer

    FrequentFlyer Mentor

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    Sep 21, 2004
    Configuration: two 921s running off DPP44 switch with separators plus a 510 and a 311.

    Background: My 510 and 311 have never had problems. I had lots of problems on both 921s as below until I read here to use ports 1 & 4 on the DPP44. That seems to have solved it completely on one 921 but I still have a problem on the other 921 as follows.

    Current problem: One 921 will lose satellite lock at least once a day. When I get home from work and turn it on, it generally will have the "lost lock" message on the screen or a black screen. The guide will still work as will viewing of DVR material that was previously recorded; however, the system is very sluggish during this time. Even when I have lock, sometimes just channel surfing will result in a "lost lock" or black screen as described above.

    Fix: About half the time, I can get the 921 working again by simply disconnecting the satellite cable from the receiver and then reconnecting it (without having to reset the receiver). If that does not work, I can pull the smart card and reinsert and that reboot will usually do it if the simple cable disconnect/reconnect did not. I find that I usually do not have to fully power cycle the machine to get it running again.

    Extra info: this box is probably 250-260 feet from the LNBs. I know that is beyond the rated distance. However, if I do a signal check when everything is working, the signal is the same as on my shorter runs. I do have a simple line amplifier at a break in the cable between the switch and this receiver. It does not seem to make any difference. I had my installer pull brand new 2200GHz RG6 to this receiver so I know the cable is not bad. We are using Digicon connectors on the cable.

    Questions: does the behavior match the problems one would expect from a "too long" cable run? Why does simply disconnecting and reconnecting the cable frequently solve the problem? Is there anything I can do to extend the 200 foot limit? My installer says that using RG11 from the switch to the dish won't help since I'd still need RG11 from the switch to the receiver.

    I have gotten nowhere with Dish tech support and I have suffered through this for months. Any guidance will be greatly appreciated.
     
  2. boylehome

    boylehome Hall Of Fame/Supporter

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    Jul 16, 2004
    My Cable length isn't as long as yours. I don't lose locks. I have my power inserter on a separate surge protector so when I reboot the 921's, the power to the power inserter in uninterrupted.

    Also, check you cable connectors for problems as it may be a poor contact.
     
  3. Neil Derryberry

    Neil Derryberry Hall Of Fame

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    Mar 23, 2002
    I had a chart somewhere for signal loss by distance on different cable types.. I'll look for that. Long story short, long cable runs degrade signal by a mesurable amount as well as increasing the chance for EMI/RFI to further degrade the signal.
     
  4. SimpleSimon

    SimpleSimon Hall Of Fame

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    Jan 15, 2004
    What Neil said, PLUS, the voltage drop on a long run can be significant. Is the cable center conductor pure copper, or copper-clad steel? Steel is NOT good for long runs.

    Replacing your runs with (expensive) RG-11 cable could very well be a solution.

    Also, moving the switch to halfway down the long run might help.

    I didn't see where you say which 921 has the power inserter and which has the amplifier. I see various problems depending on that configuration.

    Finally, do NOT make a habit of pulling the smartcard - you WILL wear out the contacts and turn the 921 into a doorstop.
     
  5. FrequentFlyer

    FrequentFlyer Mentor

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    Sep 21, 2004
    Thanks to all for input so far.

    The 921 with no problems has the power inserter. The one with the problems has the amplifier (that was a recent addition). I have tried the power inserter on both 921s (no amp). The problem seems to be there whether or not the power inserter is connected.

    It is probably just a cable run that is too long; I just don't understand why disconnecting and reconnecting the cable makes it work again (for a while).
     
  6. Mike500

    Mike500 Hall Of Fame

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    May 10, 2002
    Forget the so called amplifier.

    For very long cable runs, I have a supply of Monster Cable rg6. It was on the expensive side, but it save the day. The center conductor and the shielding braids are both solid copper. This works much better than even coax with just a solid copper conductor. Cables rated UL CL3 handle more current than the standard CL2. The Monster stuff is CL3.

    Most rg11 has copper plated steel center conductors and aluminum shielding. Their advantage is that the center conductor is a larger gage.

    Unfortunately, it did not sell well due the the high cost, and Monster Cable no longer makes it. Belden makes the solid copper shielding stuff, but it is special order and must be purchased in large quantities.

    The problem is not the signal but the lnb switching voltage signal. Voltage drop does not allow the voltage to switch to the higher voltage transponders. Likewise, the switching signal is attenuated.
     
  7. SimpleSimon

    SimpleSimon Hall Of Fame

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    Jan 15, 2004
    I agree with Mike - except that DishPro is NOT a voltage-switched system. ;)

    Low voltage on DP WILL cause problems, but for different reasons and with different symptoms.

    Low voltage on Legacy almost always manifests as loss of even numbered transponders - for exactly the reason Mike gave.
     
  8. tech_head

    tech_head Cool Member

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    Dec 7, 2004
    Hi,

    I was having the "Lost Lock" issue.
    This past weekend, I got on the roof and replaced all the connectors on the end of the cables. I bought a gun that installs watertight compression fittings.

    After the replacement, no issues with losing lock.

    tech
     
  9. FrequentFlyer

    FrequentFlyer Mentor

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    Sep 21, 2004
    I will replace all of the connectors if someone will recommend the best brand and tool to do it. Thanks.
     
  10. Mike500

    Mike500 Hall Of Fame

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    May 10, 2002
  11. Neil Derryberry

    Neil Derryberry Hall Of Fame

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    Mar 23, 2002
    Home Depot also sells similar compression connectors and crimp tools... expect to pay $60 for the compression crimper.
     
  12. FrequentFlyer

    FrequentFlyer Mentor

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    Sep 21, 2004
    Is there an instruction set? I know how to strip with the Shack tool, but then what if anything do I do with the braid before I push on the connector? Do I fold it back or just shove the connector on it?
     
  13. Neil Derryberry

    Neil Derryberry Hall Of Fame

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    Mar 23, 2002
    Don't fold it.. the stripper will hopefully give you a clean cut through the braid and the foil so that they are cut flush with the foam (or whatever type of dielectric the cable has). Make sure you don't end up with a strand of braid wrapped around the center conductor before you insert the cable in the connector.

    Clear as mud?
     
  14. Mike500

    Mike500 Hall Of Fame

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    May 10, 2002
    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.
     
  15. SimpleSimon

    SimpleSimon Hall Of Fame

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    Jan 15, 2004
    Mike. I must disagree. Show me a professional installer's coax stripper that will do what you say. And I defy you to pull one of my compression connectors off the cable. ;)
     
  16. Mike500

    Mike500 Hall Of Fame

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    May 10, 2002
    Simon,

    Send me a private message with your e-mail address, and I will send you a *.pdf technical manual on Snap-N-Seal connectors.

    The shielding of the coax provides the return path to complete the circuit with the center conductor.

    While a compression connector might work with the shielding cut off, folding it over anchors the shield with the 180 degree fold to keep the shielding from being pulled back into the coax's jacket. It is clear that the center tube provides even a high degree of surface contact with the shielding, but folding it over doubles the surface contact. The shielding wires are generally fine aluminum, so doubling the contact surface and locking it means that it is less likely to be damaged by corrosion. Aluminum wires with cadmium or nickel plated connectors are subject from galvanic electrolytic corrosion from moisture.

    Connectors have failed internally but still apear intact on the outside and still cannot be pulled off.

    I've posted this information on the dealer board, and I was surprised to find out that many of them did not realize that the shielding should be folded back.

    They went to taper sealed "Digicon" connectors, because of trouble with installers using poor practices with hex crimps. Using undersized or oversized hex dies was the problem. Properly applied hex crimps are as good as tapered or compression connectors. Compression connectors were developed, because operators failed to correctly adjust and use the taper seal tool.
     
  17. FrequentFlyer

    FrequentFlyer Mentor

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    Sep 21, 2004
    Mike500,

    Is this the right cable?

    Monster Cable CIPRO RG6-500 High Performance Coaxial Cable

    95% braided copper and 100% bonded foil shield to reject noise
    RG-6 level coax cable
    UL listed
    CL3 certified
    Linear footage marked on cable
    Comes in E-Z pull box

    Seems to be available from some sources at $50-60 per roll, and then from some at $150+ per roll. There is also a quad-shield version for a little more money. Any idea which is right?
     
  18. Mike500

    Mike500 Hall Of Fame

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    May 10, 2002
    Might be what you need. Just make sure that it has a solid center conductor.
     
  19. FrequentFlyer

    FrequentFlyer Mentor

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    Sep 21, 2004
    All of my aforementioned problems were solved by replacing the RG6 with RG11. For what it's worth, the 921/942 receivers had problems on the long cable run while the 311 did not.
     
  20. absmith

    absmith New Member

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    Oct 22, 2005
    Hi everyone, I don't have too much to add here, but for my mother's sat dish (only 80ft run to DPP34 switch) to her 721 I went with the top end permaseal RG11 connectors, and high end RG11 cable. I ran 4 new strands and made perfect crimps. Signal strength did go up a little on 110, 119, and I think 121 a little. But unfortunately I still get cannot LOCK when trying to go to 121 channels.. 110 and 119 work perfectly.

    I bought a used DPP34 switch on ebay to replace the one that was up there and get the same result. :( I just don't get it.

    At least the RG11, while costing me a total of over $200 to run, looks groovy and should last a thousand years it's so huge.
     

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