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

Time for a re-alignment?

Discussion in 'DIRECTV Installation/MDU Discussion' started by TJStaar, Jul 30, 2008.

  1. TJStaar

    TJStaar AllStar

    63
    0
    Aug 1, 2006
    Hi all,

    I checked my signal strength on 99(c) in anticipation of the new bird and the readings were in the 70's and low 80's. Knowing that things are still being worked out on that, I thought I'd check 103(c) and here's what I got.

    1-8 81 77 79 77 78 75 77 74
    9-16 77 74 80 74 81 76 na na
    17-24 84 na na na na 76 na na
    25-32 na na na na na na na na

    They seem low, though I haven't really had reception problems. 101/110/119 are all great at mid to upper 90's.

    I have a 5lnb slimline. The receiver is an HR20-100. My other HR20-100 was about the same, and my H20-600 was slightly higher, but still low to mid 80's.

    So, do I need re-aligning?

    Thanks,

    Todd
     
  2. Mertzen

    Mertzen Hall Of Fame

    3,682
    0
    Dec 8, 2006
    Those levels could be higher. But D* won't send someone out for those values unless you have break-ups.
     
  3. techrep

    techrep Hall Of Fame

    1,056
    0
    Sep 15, 2007
    Notice how your even TPs are a little lower, across the board, than the odds? It appears that you are about 1/2 turn off on the azimuth.

    Those readings are good enough but can be tweaked a little if desired. It is unlikely that Directv will send anyone out with signal strengths over 70.

    Is your slimline a Calamp?
     
  4. TJStaar

    TJStaar AllStar

    63
    0
    Aug 1, 2006
    Thanks for the replies. I'm not sure what a Calamp is. The dish was installed in March (replaced the 3 LNB), so it's pretty new. We've had some pretty vicious storms and high winds since then, so it may have moved a bit.

    Todd
     
  5. mcbeevee

    mcbeevee 97% Complete

    1,283
    0
    Sep 18, 2006
    My Slimline readings for 99c/103c are in the 77-88 range (101 is 95+). If the mast is plumb, is tweaking the azimuth the next step?

    :)
     
  6. techrep

    techrep Hall Of Fame

    1,056
    0
    Sep 15, 2007
    Calamp is a brand (like Andrew, Eagle Aspen, or Wistron) and the series 1 and 2 dishes had some questionable LNBs. Your replacement dish is too new to be one of these.

    Your signal strengths are fine and it would take some time and effort for just a little increase.


     
  7. techrep

    techrep Hall Of Fame

    1,056
    0
    Sep 15, 2007
    Probably, if you see the odd TPs being higher than the evens (or vice versa) that is a sign that the dish is not pointed at the peak of the ka signal. Moving just a little bit left or right (1/2 turn of the fine adjustment bolt) will change the signal strength numbers a fair amount. After peaking azimuth, an equally small change in the elevation fine adjustment bolt may or may not give an increase in signal strength.

    If you adjust elevation, don't loosen the elevation lock down bolt to much or the dish will slam down;


     
  8. K4SMX

    K4SMX Hall Of Fame

    3,433
    0
    May 19, 2007
    I usually advise people to adjust the EL first, because gravity causes everything to sag a little over time. :) Sometimes that's all it takes. Check the security of the lag screws in your mast's mounting plate first, however. Those frequently back out of the structure a little over time.

    When adjusting the EL, you don't have to worry about your dish dropping precipitously as long as you don't loosen the 1/2" nut behind the fitting which holds the head of the fine adjustment bolt. Just loosen slightly the two lock down nuts on the bracket which is attached to the back of the dish. (Some mounts have only one.)
     
  9. mcbeevee

    mcbeevee 97% Complete

    1,283
    0
    Sep 18, 2006
    Thanks for the info. I did notice the odd tp's are 3-6 higher than the even tp's.

    :)
     
  10. ironwood

    ironwood Icon

    673
    0
    Sep 20, 2007
    You can tell azimuth is off just by looking at the numbers. You must be genius.
     
  11. jefbal99

    jefbal99 Hall Of Fame

    2,838
    0
    Sep 7, 2007
    Had to tweak my tilt and dither today, got my KA signals from 59-71 up to 88-95

    it was very easy to do and very successful
     
  12. K4SMX

    K4SMX Hall Of Fame

    3,433
    0
    May 19, 2007
    This is kind of an interesting phenomenon. Back when D10 went live last September, texasbrit first picked up on this odd/even disparity/misalignment issue from somewhere, and it was rather quickly confirmed by many posters with misalignment problems. We were pretty sure it was confined to misalignment in the EL axis, because so many posters were reporting that correcting the EL evened them out at uniformly higher numbers.

    I noticed in one of his posts the other day he was saying it could be observed from misalignment in either axis, but I haven't seen anything to support that here. Maybe he's seen something over at the DirecTV forums. AFAIK, no one here has ever done any detailed tests to confirm whether misalignment in the AZ axis also causes this phenomenon. So for the time being, I'm sticking with the presumption that it shows up in the EL only, because that's been proven many times over. We do know that which are the higher numbers, the odds or the evens, depends on whether the EL is too high or too low. But I've lost track of which is which. It's really rather immaterial. Reports here would suggest that you adjust the EL first, if you have the "odd/even disparity."
     
  13. techrep

    techrep Hall Of Fame

    1,056
    0
    Sep 15, 2007
    If I say something a little different than K4SMX, all bets should be on him. :bowdown:
     
  14. texasbrit

    texasbrit Well-Known Member

    5,083
    87
    Aug 9, 2006
    I originally noticed the odd/even disparity when I accidentally misaligned my dish when trying to "fine tune" it. It seems to be mainly related to elevation, and is something to do with the different characteristics of the dish between the two different signal polarizations. The comment I made about misalignments in all three axes was not really related to the odd/even phenomenon - someone had posted that you did not need to adjust tilt to get the best signals on 103c, and I responded by pointing out that all three axes were involved in getting the dish to the correct place where it reflected the signals correctly to the LNB. But that for satellites close to 101 (the dish being aligned on 101) the tilt was unlikely to have any significant effect unless it was very incorrect. That's also why the SL3 dish which receives 99/101/103 can essentially operate using a tilt that is preset by zip code - the need to adjust the tilt to get peak 99/103 signals is very unlikely. On the SL3 you should just need to set the tilt to the correct value for the zip, and then set up on 101 using azimuth/elevation, then fine tune az/elevation for either 103 or 99 and that should be it. Fine tuning the tilt should have virtually no effect at all. .
     
  15. buzzdalf

    buzzdalf Godfather

    268
    0
    Jan 27, 2003
    texasbrit, you referred to this being true for the SL3. What about older slimline dishes? I put mine up last summer, is it a SL1 or SL2? I've been "fine tuning" my alignment and I think I have it all messed up, but I know that adjusting the tilt is having an effect on my signal strength. Are you saying I should just set it back to the zip code setting and tweak the other axes? Or am I using a different version of the SL and maybe this doesn't apply?
    My whole mess started when my lag bolts holding the mast mounting plate loosened (as was mentioned above for being a frequent culprit) and I didn't catch it before I had everything messed up by the way.
     
  16. K4SMX

    K4SMX Hall Of Fame

    3,433
    0
    May 19, 2007
    You have an SL5. Don't know where "tex" has gone, but yes, set your tilt back to spec. It's rarely off by much. Since you're all "messed up," please see:

    Supplemental Alignment Tips
     
  17. texasbrit

    texasbrit Well-Known Member

    5,083
    87
    Aug 9, 2006
    Agree with K4SMX. If your dish settings are screwed up, you need to start again from the "nominal" settings.
     
  18. ironwood

    ironwood Icon

    673
    0
    Sep 20, 2007
    Usually odd/even disparity occurs when signal readings are going way down - below 30s or 40s. I didnt notice it when signal was slightly below its peak, lets say 10-20 degrees below the peak.

    I seriously doubt that you can tell whether its Azimuth or Elevation or both that need adjustment.
     
  19. K4SMX

    K4SMX Hall Of Fame

    3,433
    0
    May 19, 2007
    To the contrary, there are literally dozens of 103(b)/(c) signal strength grids posted by members since last September which show the disparity between the odds and the evens starts to appear almost as soon as you leave perfect alignment, and it's quite noticeable when signals are in the 70's and 80's. I agree with texasbrit that it's probably caused by RH vs. LH polarization as you move the dish through the perfect alignment point.

    It's really no big deal whether it's caused by the AZ, the EL, or both, since I guarantee you that anyone who goes to the trouble to get to their dish for re-alignment is going to adjust both....:)
     
  20. buzzdalf

    buzzdalf Godfather

    268
    0
    Jan 27, 2003
    K4SMX - thank you for the link to that post. I think that is exactly what I need. I will be re-doing my setup tomorrow after work based on that great info :)
     

Share This Page