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LNB Drift Detected??

Discussion in 'ViP612/622/722/722K DVR Support Forum' started by jgurley, Apr 29, 2007.

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  1. jgurley

    jgurley Legend

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    Feb 1, 2005
    I have ver. 4.03 and ran System Info. last night and got a warning "LNB Drift Detected". The details read 0x0e, 0xa1, 129(e-7.45) 0o.00

    Can someone tell me what the e-7.45 means? I'm assuming that the "e" likely means elevation.

    Thanks
     
  2. putabengali

    putabengali AllStar

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    Apr 28, 2007
    drift is a poor choice in wording, but what it's detecting is the likelihood that the lnb will fail in the near future. Anything less than -8 or more than 8 requires a service call to replace lnb. The good news is that dish just launched the "LNB DRFIT SERVICE CALL" which is free regardless of warranty status. So if the number currently saying 129(e-7.45) goes to 129(e-8.00) or anything lower, call dish and get your free replacement
     
  3. putabengali

    putabengali AllStar

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    Apr 28, 2007
    oh, and 'e' stands for 'even'... as in even numbered transponders
     
  4. jgurley

    jgurley Legend

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    Feb 1, 2005
    Thanks for the info. Just talked with Tech Support and have a service call scheduled. She said the software is programmed to detect potential problems so they can be fixed before the satellite actually goes down. I'm impressed.
     
  5. BNUMM

    BNUMM Hall Of Fame

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    Dec 23, 2006
    Don't get too excited. I am an installer and I have seen the lnb drift error and the problem was not the lnb. Make sure the problem is fixed be the installer leaves because it may be something else.
     
  6. jgurley

    jgurley Legend

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    Feb 1, 2005
    Could this "problem" be caused by a tree limb partially blocking 129? I lost all 129 signals when a large tree started sprouting its leaves, cut one large limb and got 129 back with signals better then ever. I was sure I had solved that problem, but now I"m wondering if another limb could still be interfering. I told my wife today I should just go ahead and cut this second limb figuring it may be just a matter of time before it grows into the 129 path. This cutting was done before I checked System Info so I don't know if I was getting the "Drift" message or not.

    Mmmmm, I think I should just go ahead and cut the second limb and see what happens. I don't want the Tech to have something to blame this "Drift" message on. What do you think?

    P.S. These limbs I'm referring to aren't ones you take off with a lopper. I'm talking about climbing up about 20 feet with a chain saw, the limbs are about 8-10 inches round at that height and 15 to 20 feet long. This is no "girlie" tree!!!
     
  7. May 1, 2007 #7 of 28
    P Smith

    P Smith Mr. FixAnything

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    Mediterranea...
    "Drift" values means here changing LNBF's internal oscillator frequency out of normal range ( +- 5 MHz) what can not be or could hardly compensated by satellite tuner circuit.

    Any problem with aiming the dish or external blockage stuff DOESN'T affect the drifting report.
    It is LNBF INTERNAL problem. If you exclude SW bug and glitches ;).
     
  8. May 1, 2007 #8 of 28
    BNUMM

    BNUMM Hall Of Fame

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    I have found that the LNB Drift message is not always a problem with the LNB. I have found from experience that it can be caused by a dish out of alignment or possibly a deformed dish.
     
  9. May 1, 2007 #9 of 28
    P Smith

    P Smith Mr. FixAnything

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    Mediterranea...
    You found bogus reason unfortunately for you.
    The parameter CANNOT be changed by deforming dish or misalignment.
    There is LO drift
    Just for broadening your knowledge in the field, take a pick how the LNBF build in the thread.
     
  10. BNUMM

    BNUMM Hall Of Fame

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    These are not bogus reasons. They are facts. Every situation where I have seen the LNB drift message the problem has not been the LNB. I remember 3 specific situations. The first thing I tried on each was to replace the LNB. Each time after replacing the LNB I still got the LNB drift message.

    Situation 1 was resolved by simply running a check switch. The message has not come back.

    Situation 2 was resolved by aligning the dish. The message has not come back.

    Situation 3 was resolved by replacing the pan. The message has not come back.

    If you don't believe the above that is fine with me. I was only trying to inform people that replcing the LNB may not solve their problem and that if it doesn't then here are a few things to try. These forums are meant to help not to criticize suggestions.
     
  11. P Smith

    P Smith Mr. FixAnything

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    Mediterranea...
    Well, I did my reservation for SW bugs, errors;
    but misalignment, damaged pan - sorry I can't take the points as EE (plus considering my SW/HW years experience).
    Perhaps SW so baldy written and LNBF reporting bogus info ... Then I don't understand the whole idea what Dish try to implement.
    Wrong input ( garbage in ) cannot be processed for make good decision.

    Whole picture will be totally stupid if your observation have merits. :(
     
  12. kmcnamara

    kmcnamara Icon

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    Jan 30, 2004
    Here's to you Mr. Awesomest Engineer Ever. :rolleyes:

    The guy makes some valid points of things he's observed and you effectively tell him he has no idea what he's talking about (at least I think that's what you said). You need to get off your high horse.
     
  13. BNUMM

    BNUMM Hall Of Fame

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    Maybe I should avoid posting any of my troubleshooting experiences. Apparently I am too stupid to post here. I could post my background, education and experience but that would be pointless as I have always fixed the problem.
     
  14. Ron Barry

    Ron Barry 622 Tips & Trick Keeper DBSTalk Club

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    Dec 10, 2002
    Ok.. lets watch the personal insults. it is unnecessary and does not add value here.

    We are all here to help and to offer our own experiences. It is ok to have different viewpoints and to disagree but lets try and avoid the insults. I have edited a few of the the less friendly remarks from the posts above.

    I plan on adding this to the Tips and Tricks thread so lets keep things rolling and on a constructive road.

    And I believe P. Smith's (if I am reading it write) stupid comment was regarding that if your observations are accurate then the reporting mechanism is flawed. I don't think he was calling you stupid. If he does correct me on this point, I will remove the comment but I don't think that was the intention.

    Opinions are always welcome here especially experiences from the field. Just because something does not make sense does not necessarily make it not accurate. And yes.. The main purpose of these forums are for helping and I all input is welcome. :D
     
  15. P Smith

    P Smith Mr. FixAnything

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    Mediterranea...
    Sorry for drifting the discussion to personal aspects - it WASN'T my intention; I did attempt to stay with real physics, not who did that.

    I would rather have a conversation how this diagnostics works and what factors contribute to the issue.
    But, we fall into discussion about different points.

    Want to add my [personal] vision of the discussion ( actually, why I mentioned RF engineer level ) - let me do it little easy - imagine you're auto mechanic ( I think any man should feel he knows everything about car's guts :) ) and other person telling you: that engine sporadically revving, black smoke coming out, etc BUT if you cleaned windshield or after you did wheels alignment the symptoms goes away. What you'll say ?

    I expected little higher professional level talk of the issue.
     
  16. jgurley

    jgurley Legend

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    Feb 1, 2005
    I guess it's time I jumped back in here since I started this discussion. For me putabengali's posts on 4/30 was most helpful.

    When I called tech support the CR knew exactly what I was talking about and immediately scheduled a service for tomorrow afternoon. I received a call from my local Dish service company yesterday for confirmation and I asked him if he had dealt with this issue before and he too knew about the problem. He said the LNB needed replacing.

    Of course the only question I have today is if the techs they send out also know what they're doing. I'll just wait and see and let you guys know what happened.
     
  17. jgurley

    jgurley Legend

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    Feb 1, 2005
    Here's an interim report. I cut that other limb I referred to earlier and can see no change. Still getting the lnb drift message and my signals on sat. 129 are low of 62 (tp22), the rest ranging from 68-89 depending on the TP. Based on the info I have in this area those are quite good so my dish is most likely aimed properly.
     
  18. boylehome

    boylehome Hall Of Fame/Supporter

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    Jul 16, 2004
    I have LNBF drift on one LNBF used for 110 satellite. This LNBF connects to a DPP44. The ViP622 detects the drift at is -5.83e.

    I took a good LNBF and swapped it with the reported drift LNBF.

    After making the change, I checked the system information again. Hmmm, same drift reported for the 110 satellite LNBF. I swapped cabling. No difference.

    The only thing I can figure is that it is a reporting error, or there is something internally wrong with the fairly new DPP44.

    In conclusion, there is nothing wrong with either LNBF that show drift.

    UPDATE: I swapped the cables connected from the LNBF's to the ports on the DPP44 switch for 119 and 110. I ran a check switch. Once the receiver was normally operating, I checked System Info. No more LNB drift. Status is, "Good" and green colored. The problem may be switch related. The cable swap and check switch cleared the problem. Also, before testing today, I had performed check switches but LNB drift was detected.
     
  19. ezra

    ezra Mentor

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    Mar 9, 2007
    I had previously answered what lnbf drift was in a prev post about a month ago... however it is now E* policy to replace lnbs with drift valuse above +/- 8 for even or odd transponders free of charge to the customer.. I have also read some of P Smith's previous post and found them to be insightfull, however, BNUMM I correct about lnbf drift not always being an lnb issue as i have RA'd several thath have resulted in no problem founds... and the csut still kept calling back... in these cases i found the dishes were replaced, switches were replaced, etc, etc , until the customers intermiten signal loss was corrected.... now why would lnb drift not be caused by an internal failing of the lnbf... i have pondered that question and experimented to find my own answer... I have found that a warped dish can recreate the drift phenomenon and why.... when i was in the army setting up my uplinks i screwed up one time on one of my dish plates... my CO was not too happy cause i could not for the life of me figure out why i had such a dirty signal... all connectiosn were ok, all equipment was ok but the spectrum analyzer showed up a horrid wave form.... then i looked over my dish and 'fixed' one of my dish plates and voila a beautifull wave appeared....it was simply the destructive interferece patern created by at slight .035 degree offset on one of my dish plates.... I believe the same holds true for a 20" dish that is not necesarily made to the best of grades and lnbs that are cheaply cast and quickly assembled in many different assembly areas...I dont believe this forum was created with the intent or purpose of having its members write up detailed equations to support their finding or having to post pictures of their spectrum analyzers. This forum is for helping others and nothing beats personal experiece because in the field all the equations or procedures meant nothing if we could not get the link up... as to the car analogy: drift would best be explained as a point at witch the resonating frequency of the individual intake runners creates turbulence with in the plenum due to inconsistencies in volume/shape or location resulting in an uneven distribution of air mass/volume per cylinder yeilding uneven power ouput per cylinder creating uneven stresses in the reciprocationg assembly leading to vibrations witch over time lead to premature decay in the main bearing/ rod bearing and premature engine failure as the ocilating frequency of the engine changes due to small imperfetions...I learned this after losing a few blocks at the track go figure.... ITBs is how i race now... also do chech in to the tech portal at dish network. the lnb drift can be found under receiver/ receiver model #. then select symptoms and go under signal loss, intermitten... follow the tshooting steps and step 3 askes if you hgave the chech details for lnb message on your sytem info screen and explains what the values of lnb drift mean....

    thanks for your time and patience...
     
  20. BNUMM

    BNUMM Hall Of Fame

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    I am glad you confirmed that one problem could be a deformed dish. I am still confused as to why a check switch being performed would correct the problem.
     
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