Help with tracking the arc

Status
Please reply by conversation.

bobvick

Pub Member / Supporter
Original poster
Pub Member / Supporter
Lifetime Supporter
Jul 20, 2006
4,464
2,163
Northwest Alabama
I have been trying to get my C-Band dish tuned in for a couple of weeks. I have found my true south satellite at 87W (I am at 87.7W and 34.043N). I get AMC3 very good, quality is in the 70's on most transponders and in the 70's and steady even on the DVB-S2 RTV feeds. I can get Galaxy 28 @ 89W, Galaxy 17 @ 91W (this seems to be the strongest signals I get), I have yet to find 93W or 95W, but I have found 97W, and 99W, and 103W. Anything past 103, I cant seem to find, and 103W is very weak. It seems that I need some tuning toward that end of the arc. I do not know if it is the azimuth or what. The elevation and declination seem to check out well using an inclinometer. Does anyone have any suggestions on something to try? All help will be appreicated.

Thanks
 
When you use the actuator to move to 99W, Adjust the azimuth (twist of the mount on the pole) to max out your Q. Do not adjust polar elevation, that is only adjusted on your closest to south sat. Then actuator to 103 and repeat the azimuth adjustment. Continue till you're at the end of the arc.
 
I have been trying to get my C-Band dish tuned in for a couple of weeks. I have found my true south satellite at 87W (I am at 87.7W and 34.043N). I get AMC3 very good, quality is in the 70's on most transponders and in the 70's and steady even on the DVB-S2 RTV feeds. I can get Galaxy 28 @ 89W, Galaxy 17 @ 91W (this seems to be the strongest signals I get), I have yet to find 93W or 95W, but I have found 97W, and 99W, and 103W. Anything past 103, I cant seem to find, and 103W is very weak. It seems that I need some tuning toward that end of the arc. I do not know if it is the azimuth or what. The elevation and declination seem to check out well using an inclinometer. Does anyone have any suggestions on something to try? All help will be appreicated.

Thanks
losen pole mark it first.turn a little at a time left or right. Move dish with motor up or down look for signal. Edit. Sorry fat air was typing while you were posting.
 
Thanks a lot for the suggestions. I do not know when I will get to mess around with it much. Maybe I can do something on Monday. I have to have someone to help me, so I will have to wait until a friend can come over and help me with it some. We have both been scratching our heads trying to come up with what could be wrong. I felt like the elevation and declination had to be close since I found the true south. Thank you all a lot for your input, I appreciate it. When I get this project somewhat completed (I don't think you ever really get "finished" with a hobby like this) I am going to see about getting me about a 1M dish and motor to do Ku band. I could have did both with the 7.5 footer, but I wanted the best possible signal strength I could get, so I got a single ortho feed with 2 norsat lnbs on the C-Band. Figured if I could get the C-Band to work, then perhaps doing the Ku dish would not be so bad.
 
... I have to have someone to help me, so I will have to wait until a friend can come over and help me with it some. We have both been scratching our heads trying to come up with what could be wrong. ...

When I did my first BUD I found out that sometimes

one brain is better than two! :D

I did like FaT Air suggested in this thread but when

there was two of us we just confused each other! :argue:

It only took me an hour or so by myself! :up


Concentrate... :lalala:
Be one with your dish...
"Tracks on, tracks off..."

Repeat if necessary! ;)
 
I might go home and give it a try this evening. Nothing ventured, nothing gained I guess. As long as I mark the pole on the position it is on now, I can always go back (maybe!). Thanks for the suggestions.
 
Sounds like your due south position if off a shade.

I would start with getting my zenith position. That is essentially when the dish is at its highest - not leaning at all either east or west. Zenith is where it should be when it is pointing due south. If you know how many "clicks" you have per degree, then I would multiply that number of clicks by .7 (87.7 minus 87) and then click that number east off of zenith. If you don't know how many clicks per degree you have, I would click a few east.

Then I'd turn the whole thing on the pole until I got the best signal on 87. Then I'd adjust up and down until I got the best best signal.

If you have a friend to help you that can work well. If you have some kind of receiver that has a signal strength meter in it (most do) and the other guy is watching TV and talking to you by cell phone telling you when your signal is strongest, that should help you dial it in.

Usually, when you can only get the satellites in a narrow bubble, it means either the elevation is wrong, or the thing is not at zenith when it aims dead south.

Good luck.
 
I adjusted the azimuth while I was on AMC1/SES3 @ 103W and now I have good signals from that satellite. I also managed to pull in AMC18 @ 105W, I can get the NBC S2 mux, but the quality ranges from the high 40's to low 60's, perhaps it needs more adjusting. The other birds I could get, 99W, 97W, 91W, all check out ok. When I went back to 87W AMC3 (my true south) though, the quality readings were down about 5 points, and I can no longer pull in the RTV S2 mux. I was getting stable quality in the 70's on the RTV mux and the low to mid 70's in quality on the other frequencies. I don't know what the problem is now. Any suggestions on how I should proceed? Thanks for the help.
 
I adjusted the azimuth while I was on AMC1/SES3 @ 103W and now I have good signals from that satellite. I also managed to pull in AMC18 @ 105W, I can get the NBC S2 mux, but the quality ranges from the high 40's to low 60's, perhaps it needs more adjusting. The other birds I could get, 99W, 97W, 91W, all check out ok. When I went back to 87W AMC3 (my true south) though, the quality readings were down about 5 points, and I can no longer pull in the RTV S2 mux. I was getting stable quality in the 70's on the RTV mux and the low to mid 70's in quality on the other frequencies. I don't know what the problem is now. Any suggestions on how I should proceed? Thanks for the help.

Here ya go Bob............. Read this... follow this... you should be good to go!
 

Attachments

  • step by step align.txt
    17.5 KB · Views: 1,169
If you Re-peak on your True South Sat, then drive back to a west sat, try to determine if raising or lowering the Dish makes a Diff. and return settings for TS Peak signal.
Next check a Sat to the East, determine needed correction.
Adjust the Azimuth until both East and West Sats need the same adjustment - up or down.
You should now have correct Azimuth, and need to adjust Declination and Elevation.

Keep in mind that every time you adjust the Dish, you will have a different position on the GBox.
 
I need a little help figuring out if I have my elevation set correctly. I went to dishpointer.com, it gives my "motor latitude" as 34.1 and my declination angle at 5.5, so will I need to set my elevation at 28.6 (34.1 - 5.5)? Or do I set it at 34.1, right now it is at 34.1.
My declination is at around 39, so, I guess that is correct? 34.1 + 5.5 = 39.6? Just making sure that I understand. Thanks for all the help.
 
I have one more question, do I need to use the "modified" elevation and declination angles found here?
 
How much azimuth adjustment did it require to peak Q on 105, from where it started at 87? If you had to do a lot, you could have been way off initially at your south sat, 87W. May just have to then touch up elevation at 87, then go back and touch up azimuth towards 105. But, if the az adjustment was very small - I think I'd double check the declination and if thats OK, check the feed centering. Just so we are all "on the same page" to say. Declination is the angular difference between your polar pivot angle. and that of the dish face(latitude + declination, sometimes referred to as "extreme angle"). Declination angle is critical to get as close to perfect to get a BUD to track properly. (as is getting the feed centered) If getting a measurement of the dish face angle is difficult on the back of the dish. Placing a straight 2x4(or some other "straight edge") vertical across the face, and measuring the angle there is a good alternative. This is assuming the feed is centered. If not, it will throw things off. Check centering by measuring from the dish lip to the edge of scalar or feed throat at 3 or 4 equadistant points around the dish. Also confirm that it's aimed at the very center of the dish. just my $.02 Just noticed something else, your modified declination should be closer to 4.91°(5°?) instead of 5.5° (Latitude= 34.043°) This will afford more accurate tracking. Especially, if your BUD is also Ku equipped. $.03
 

Attachments

  • polar_mount_pic.jpg
    polar_mount_pic.jpg
    152.9 KB · Views: 213
Ok, so to check that it is close, do I need to subtract the modified declination from the modified elevation? Modified elevation = 34.61 Modified declination = 4.91 would the correct elevation need to be close to 29.7? Or would it need to be closer to 34.61? I didn't have to do a whole lot of turning, probably from the mark I made from where it was some where around 1/4 inch or so I guess.
 
On the declination, whichever you decide to use, you just get the polar mount elevation and then make the dish elevation lower by the setting you choose,(means the polar mount has the dish aimed into the sky, but adding declination, the dish points five degrees or so lower in the sky) then leave the declination alone.

After that, all adjustments will be to elevation, to pivoting on the pole, focal length and skew. None to declination.
 
Here are some photos so you can see what kind of mount I have and what the dish looks like. Perhaps that might help a little.
 

Attachments

  • dish1.jpg
    dish1.jpg
    986.5 KB · Views: 246
  • dish2.jpg
    dish2.jpg
    801.7 KB · Views: 226
  • dish3.jpg
    dish3.jpg
    825.8 KB · Views: 215
  • dish4.jpg
    dish4.jpg
    822 KB · Views: 237
So, to be clear, I have my elevation set too high? The elevation is currently at about 34, should it be set closer to 29, if the declination is at 39?
 
Do I check the elevation at 1 or 2 on the photo below? Also should I check the declination on the edge of the polar mount marked "3"?
 

Attachments

  • dish6.jpg
    dish6.jpg
    973 KB · Views: 212
Looking at pic number 4......... Is the mount centered?? The photo looks like the pivot point of the dish is off too far to the left. The dish should pivot in the middle....... The bracket needs moved to the center unless I am seeing things.. Have a great day!
 
Status
Please reply by conversation.
***

Users Who Are Viewing This Thread (Total: 1, Members: 0, Guests: 1)

Who Read This Thread (Total Members: 2)