1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Longest Cable run?

Discussion in 'DIRECTV Installation/MDU Discussion' started by iotp, Oct 15, 2010.

  1. Nov 21, 2010 #21 of 139
    AntAltMike

    AntAltMike Hall Of Fame

    3,787
    108
    Nov 20, 2004
    College...
    If the installer is getting paid on a per job basis, then it is to his benefit to decline to perform any job that he is contractually entitled to decline if he considers his cost of completing the installation - either in labor or materials - to be excessive.

    I would imagine that DirecTV or its local representative now has a customer file for this blown installation in which the installer gave his reason for declining to perform the installation, such that he would qualify for his "kill" fee or otherwise avoid getting fired.

    If you want to give it one more shot, you can call DirecTV and explain what happened and tell them the estimated cable lengths and see if they will send someone out with foreknowledge of that obstacle to installation. Since I am not a residential installer, I do not have current knowledge of any exact maximum cable length that DirecTV will sanction as part of their standard, "free" professional installation or that they will permit as a customer approved "custom installation", but they must have such standards, otherwise, they could get unwittingly sucked into having to either perform installations that cannot be expediently completed under the terms they have with their installers or supporting installations that they do not consider to be technically valid.

    It sounds to me like this installation can readily and reliably be supported by a single line SWiM installation using RG-6 coax, since an SWM installlation can simultaneously support up to eight tuners. One downside of using SWiM over long distances is that there is usually a little more structural signal loss with SWiM than there is with a multiswitch system since multiswitches tend to be designed as "zero loss' components, whereas the splitters used in SWiM systems lose about 5 dB per two-way split or 10 dB per four-way split, at the upper frequencies. On the other hand, it has been reported here that the SWiM LNB does have automatic gain control whereas the four-wire "wideband" downlead system does not.

    Either way, your cable lengths do not introduce structural losses that would be of concern to me. It looks to me like a simple economic problem. When I installed C-band for a company owned by a mafia mobster, we were paid a flat $300 labor for an installation, no matter what, but on the east coast, we had to be able to target the western satellite arc down to under 20 degrees of elevation, and since most of our customers were in the woods, sometimes moving the dish another hundred feet away got you one more satellite on the lower arc, but the labor involved in burying a 500 foot coax even a few inches below the ground made it a dealbuster for the installer.

    If DirecTV won't pre-authorize an installation on dish as far away as this one is, you can get the hardware delivered to you by an internet dealer and self install it, or at least, self install the coax if you are not technically proficient enough to connect and peak the dish yourself. You can still have their installer peak the dish for you as part of the free installation. If you run your own coax, just remember to buy direct burial coax, with a solid copper center conductor. And it is a good practice to run a spare coax or two, just so if one or more get damaged, you won't have to trench again.
     
  2. Nov 21, 2010 #22 of 139
    netraa

    netraa Godfather

    483
    0
    Mar 27, 2007

    If it's 150-160 feet to the closest IRD, another 10-20 for loops, up the pole, and other assorted loss, and then another 50-75 to the other 2, there isn't much chance that your going to get a *D installer to put it in.

    There is a very real chance that if I were to put your system in, and then it doesn't work and you have to cancel because your not serviceable, I would end up paying your ETF, or the fine the HSP pays.

    with MRV, on a SWiM the top end cable run for a do it right and it's 'going to work' installs is 150 feet total. that counts every inch of cable, from the lnb, through the drip loops, to the back of the IRD.

    Yes, there are people that have 'one off' installs that go 200-300-400 feet. problem is they are one off's that are not supported.

    If i were to roll up on a 200-300+ foot run to IRD's with FF/PIX or mrv issues for the problem, i'm going to bounce the call as not serviceable and be on my merry way. It's out of spec, out of my control and i'm not going to kill myself trying to fix it, and put my name on a system that might never work perfect and I don't care how many times you say your 'ok' with working 'good' it's not going to happen.

    Unfortunately, your in private dealer land. both for your install, and for service.
     
  3. Nov 21, 2010 #23 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    This is where the proper use/size of splitter makes all the difference.
    I agree with the 150' using an 8-way splitter, but if you use a 4-way, then you have the same levels at 200'.

    Maybe "someday" there will be sufficient training for the installer/techs to know how to work with a splitter based system.
     
  4. Nov 21, 2010 #24 of 139
    netraa

    netraa Godfather

    483
    0
    Mar 27, 2007
    I absolutely agree.... splitters are new to the *D world, and they do basic training only. My biggest problem is, there isn't any training for the QC or the Sups that go back with the big stick and the paycheck access to risk it on a system when the official specs say 150 feet.

    it's all about the math. start with your signal strength, subtract all your losses, and see if the math works.

    problem as we all know, 'works' doesn't always mean it will pass QC.
     
  5. Nov 21, 2010 #25 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    Maybe someday that will change. I'm actually looking at something that may change/improve this. ;)
     
  6. Nov 21, 2010 #26 of 139
    netraa

    netraa Godfather

    483
    0
    Mar 27, 2007
    So, yeah.

    If you want to get into the realms of 'best case, and it should work'
    3 IRD, 4 tuners. swm starts at 950, 4 channels up from that puts you at 1350 so you can 'dumb down' your calculations to only require that freq range.


    swm lnb... -30 db, attenuated.

    160 feet of line loss at 1350 mhz is 11.95 so let's call it 12

    now comes the tricky part.

    If you slap a 4 way on it right there, that's another 10

    now you have yourself another 50 foot of line at another 3.75 db call it 4.

    SO, you start at -30 and need to stay at -60 or better.

    at the PI, your going to have -52, call it -53 at the IRD for barrels and jumper and other misc.
    at the end of the line at the furthest IRD your going to have -56-57.

    So, yes.

    since your only putting 3 IRD's on the line it will work.

    =======================
    If you ever want to add a couple more dvr's and fill out the swm...

    re-calculating for 2150...

    swm lnb -30
    drop leg -15.86 call it -16
    splitter -10
    50' to other IRD's 5

    -56-57 at the PI, and -61-62 at the end of the line....

    your barely/not working any more.
    and that's without any 'extra' loss due to murphy and his book of laws.
    slip the fact that we 'want' -50 db at the IRD and now your looking at why it's such a hot potato to do a long run install.
     
  7. Nov 21, 2010 #27 of 139
    AntAltMike

    AntAltMike Hall Of Fame

    3,787
    108
    Nov 20, 2004
    College...
    No need to recalculate at 2,150 MHz, because the only distribution systems that go up that high are WB systems, which use loss-less multiswitches or no multiswitches at all. A fully utilized SWiM has its highest center frequency at 1,790 MHz (the centers start at 974 MHz and go up 102 MHz per interval). Are the Ka transponders 60 MHz wide? If so, the high end of the SWiM band is 1,820 MHz.

    Still, the questions here are, 1) can this prospective customer get DirecTV to install a dish 150 to 160 feet away, 2) If so, how can he get them to do it, and, 3) if they won't do it, can he privately install his own system and have it be reliable?

    Unless he has a day to waste, he really should tell the DirecTV CSR what the cable length are, and if they reauthorize the installation, then when the installer calls to report that he is on his way, also tell him what the lengths are.

    If he self installs it as an SWiM, he should do himself a big favor and either use a single strand of RG-11 or put in a 14 dB Sonora booster at the entry point. I don't think he needs either, but it is so much cheaper to do either during the installation than after, and it will leave a performance cushion for future system expansion.
     
  8. Nov 21, 2010 #28 of 139
    joe diamond

    joe diamond Hall Of Fame

    3,071
    0
    Feb 28, 2007
    Notes do not make it to the tech many times with some HSPs.

    My fav was a cx to CSR conversation that went...."look. I am paying for everything and the people I have hired have my permission to come on the property. Your people will be charged with trespassing. IF they touch my equipment they will be charged with vandalism. Do not plan to touch my wire...just turn on the damn boxes now..or when the damn rain stops."

    It was a new construction maxi mansion and the cx had been through what is being discussed and just got out the check book to make it EZ on himself.

    I like the SWM & RG 11 idea. But $$$$$$$$$$$! I don't even own the tools to splice the cable or have any fittings. I'd like to know what the increase in signal over distance would be doing it that way. You never know when it could be used.

    The Sonora product seemed to add huge amounts of service to very long runs in a big house served from a dish I had to put at a great distance.

    Good one!

    Joe
     
  9. Nov 22, 2010 #29 of 139
    AntAltMike

    AntAltMike Hall Of Fame

    3,787
    108
    Nov 20, 2004
    College...
    This eBay seller has 150 foot preconnecterized lengths of buryable RG11 for $49.99 including shipping, and $59.99 for 200 foot lengths. I'm sure he could make one 160 feet for a few bucks more than $49.99, because I'm sure he cuts it to order. With SWM, you only need one coax to fully support up to eight tuners.

    http://cgi.ebay.com/150-FT-RG-11-CO...342?pt=LH_DefaultDomain_0&hash=item230ba4e936

    I don't have a handy frequency attenuation chart available, but I'd expect the loss difference between RG-6 and RG-11 at 1,800 MHz over 150 feet to be four to five dB.

    You can buy the Sonora 14dB gain amp with an internal, 2.3 MHz return path here for $57.99 plus shipping.

    http://www.solidsignal.com/pview.as...200mA-Transformer-(LA141RT)&c=Amplifiers&sku=

    People who paid $4,000 for C-band systems that supported just one receiver and took 30 seconds to move from one end of the arc to another would not consider those prices to be dealbusters.
     
  10. Nov 22, 2010 #30 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    Since the highest SWiM frequency is 1800 MHz, the loss for 160' of RG6 is about 14 dB.
    50' comes out at about 4.4 dB.
    A 4-way @ 9.5 dB.

    Is your name "murphy"? :lol:
    I have a contract out on you if it is. ;)

    No one should ever try to push any of these to the "last dB", but clean runs with the fewest connectors/barrels is the best way to go, and moving the PI to a shorter run, keeps it out of the loss path on the longest run.

    "Think" before you simply "slap on" another 2-way and figure out what you're doing so all receivers have the highest signal "you can" get them.
     
  11. Nov 22, 2010 #31 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    "If you want" -50 dBm at the receiver:
    -30 dBm out of the SWiM - 14 dB for an 8-way, leaves you with only a 70' coax for -6.12 dB and the receiver's input being -50.12 dBm.

    "The real truth" is somewhere between -54 dBm & -62 dBm.
     
  12. Nov 22, 2010 #32 of 139
    AntAltMike

    AntAltMike Hall Of Fame

    3,787
    108
    Nov 20, 2004
    College...
    One other factor that tends to confound these calculations is that I can see on my spectrum analyzer that the strengths of the 101 odds transponders, which are all supposed to be exactly the same, vary by about half a dozen dB. I'll try to stop by some place where I can eyeball that more precisely today.

    When Sonora claims that an AGC amplifier has a certain output level, what they really mean is that when fully loaded with exactly equal strength transponders, that would be their level, but as best as I can determine from their literature, their AGC circuit is one that maintains a certain constant total (milli)wattage output, so if, for example, you only fed half as many equal strength transponders into an amplifier that Sonora calls a -30dBm. output amplifier, their outputs would be -27dBm.

    When you have sixteen Ku band transponders that are supposed to be of roughly equal strength but they instead vary by half a dozen dB, then the strongest ones coming out of a so called -30dBm AGC amp might have a signal strength of around -28dBm, whereas the weakest might be closer to -34dBm. I remember when DirecTV was sending out anemic transponder 30 and 32 signals. There was little we could do to sustain them in large distribution systems because if we amplified the entire evens band, the intermodulation of the stronger, spot beam transponders would decimate the weaker ones. FWIW, the strength of my local spotbeam transponder 18 is way down from what it was a few years ago. I suspect that was done deliberately to reduce some intermodulation byproducts.
     
  13. Nov 22, 2010 #33 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    Comparing Sonora "wide band" amps with AGC, isn't the same things as the SWiM. The SWiM has 1 fixed channel [guide data] and 8 tunable channels 100 MHz wide. It would be interesting to see what your spectrum analyzer shows on the SWiM output. Does each channel have it's own AGC? :shrug:
     
  14. Nov 22, 2010 #34 of 139
    joe diamond

    joe diamond Hall Of Fame

    3,071
    0
    Feb 28, 2007
    Thanks,

    I'll use their prices and your estimate for future quotes.

    RE installation costs...I have seen "emergency install today" on WOs; read mother in trailer with many kids at home. My own brother paid $900.00 for a same day DTV 2 receiver prewired townhouse installation. The cx I was mentioning probably had the horsepower to buy Directv just to fire the CSR who was reading from a script after he had already been screwed by the local HSP.


    After all it is only TV with commercials.........or it is only commercial messages with a little porn?

    Joe
     
  15. Nov 22, 2010 #35 of 139
    AntAltMike

    AntAltMike Hall Of Fame

    3,787
    108
    Nov 20, 2004
    College...
    I had one of those once. She was on the board of Directors of Hughes, as one of its largest stockholders, and her account was "comped". DirecTV is very secretive about its comped accounts, and the lowest Hughes employee who was even allowed to access them was a vice-president. An unfortunate consequence of that was that whenever a multimillionaire, comped customer wanted his account serviced in the evening, when no vice-president was available, he couldn't get his problem addressed as readily as his chauffer, gardener or personal assistants could get theirs serviced. I recommended to this customer that they simply cancel their free service and pay a hundred bucks a month for an account that they could get serviced.
     
  16. Nov 22, 2010 #36 of 139
    AntAltMike

    AntAltMike Hall Of Fame

    3,787
    108
    Nov 20, 2004
    College...
    I think that, from a practical standpoint, they'd have to be individually controlled for a number of reasons. One is that there is a significant power differential between Ku and Ka transponders. Another is that Ka signals weaken more rapidly when going through rain than do Ku signals through the same atmosphere, and since the system was designed when it was imperative to get HDTV signals from 110, the chances are that the customer would often be experiencing much different rain density along the 110 path than on the 99/103 swath.

    It would be an all-day task for me to analyze SWiM AGC performance. I would have to call for programming that I knew to be on different satellites, and then start partially blocking each feedhorn waveguide to see which hump on my screen corresponded to which program, and then to roughly estimate how much stiffness and range the AGC actually had. As my late father often said, "Some of us have to work for a living", and unfortunately for the cause of science, I am still one of those who does.
     
  17. Nov 22, 2010 #37 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    Getting back to the topic a bit.

    Sonora Designs has a good pdf for SWiM which can be found here: http://www.sonoradesign.com/images/sheet_SWM8.pdf

    Here are a few of their layouts:

    SWiM LNB 1S.PNG

    SWiM LNB without their LA 141R amp 1Sa.png

    SWM8 with & without amp 3s.PNG

    SWM8 with amp & 8-way splitter 4s.PNG

    Their amp adds another 150'

    If you have to add a 2-way splitter near the receiver subtract 50' from the coax to have the same power at the receiver.

    Now for some idea of what RG59, RG6, & RG11 RF losses are:

    [​IMG]
     

    Attached Files:

    • 2s.PNG
      2s.PNG
      File size:
      209.3 KB
      Views:
      29
  18. Nov 23, 2010 #38 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    After posting the information from Sierra Design, I wondered about their -61 dBm for the receiver.

    Right now it's raining, with the weather radar showing green with some yellow near by.

    My setup is a SWiM LNB, 90-100' of coax, with a 2-way splitter, feeding the PI, feeding a 4-way splitter, and a HR20-700 with a DECA.

    Splitter losses are given as max, so actual loss may be less at any one frequency.

    The SWiM PI is spec'd at 1.5 dB max.

    The setup should be:
    SWiM out = -30 dBm
    90' coax = -7.87 dB @ 1750 MHz.
    2-way splitter = -4.8 dB @ 1000-1750 MHz.
    4-way splitter = -9.5 dB @ 1000-1750 MHz.
    PI = -1 dB

    This should have about -53 dBm at the HR20-700, but this could be -50 dBm given this isn't measured power.

    Not having a step attenuator and a power meter, I used splitters, with terminations, and the signal screen on the HR20.

    The SWM screen showed 97 on the first and 91 on the highest.

    I added a 4-way + a 2-way + another 2-way

    The SWM screen showed 96 on the first and 86 on the highest.

    This should be 9.5 dB + 4.8 dB + 4.8 dB = 19 dB

    This means this receiver is only showing a 5% drop at around -70 dBm input.

    Not every receiver is going to have the same sensitivity and -70 dBm isn't a measured level. Given this, it still looks like a power level of -60 dBm is a "real truth".

    This means the SWiM to receiver losses can be 30 dB for the splitter/coax combination, which matches Sonora Designs specs. :)
     
  19. Nov 24, 2010 #39 of 139
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

    42,683
    348
    Dec 9, 2006
    These are or should be the max lengths for -60 dBm
    [​IMG]
     
  20. Jun 4, 2011 #40 of 139
    geaux tigers

    geaux tigers Icon

    551
    0
    Nov 10, 2005
    Has anyone ever used one of these to compensate on a long cable run?

    http://www.solidsignal.com/pview.as...TV-SWM-Amplifier-(CTSLA)&c=Multiswitches&sku=

    My in-laws have a long cable run to a SWM receiver in the back bedroom. The total cable run may be close to 200 feet. Everything works well except for the Whole House DVR Service over DECA. It works for a few minutes and then you lose the connection. I am hoping that the above amplifier will solve the problem.
     

Share This Page