Motor Drift?

[dogstar1313]

Is there such a thing as motor drift? The reason I ask is that when I first installed my system my dish was aligned so that using USALS every bird was right on the money. Now after several months it's gotten to the point where USALS doesn't even get me anywhere close enough to the correct location to get a signal lock. I've had to switch everything to 1.2 mode and nudge west several times to find the sweet spot and then program that in for each bird. Has anyone else experienced such a phenomenon? Could the motor be out of calibration? My motor is a SG2100.

 

[PSB]

Should not be the motor its self, but it may have moved slightly, you maybe able to fix this from the remote by simply off-setting your longitude very slightly. If it gets worse go the other way slightly!

 

[dogstar1313]

Thanks Pete! I'll give that a shot. I like those solutions that don't involve me getting on a ladder in the winter time.
Although our winters here in Tennessee have been more like rainy seasons the last decade or so thanks to global warming.

 

[PSB]

45 deg. C here in the Twin Cities today!

Now where did I put my Speedo's?

 

[Larry1]

It's only -8 c here right now, but going to be warm tomarrow with a high of +6 c. Still have not had the "usual" bitterly cold spell of weather yet this winter.

If the dish still tracks the arc correctly, then it sounds like the receiver/motor is calculating it's settings wrong. (i.e. motor may need a reset) If your quality is not as high as you move the dish across the arc, and is lower the further you move from your true south, then the motor may have moved on the pole. Also, the dish may have moved on the motor shaft. The stab web site had some good diagrams of what to expect when things were not aligned properly. The have the users manual online.
http://www.fortecstar.com/Estore/store/Assets/userguide/75-userguide.pdf
Try here pg 10 for fine tuning

 

[fulszjep]

motor drift

Using my primestar dish it would have motor drift. I think it was the weight of the dish. I have the same motor.

 

[Sadoun]

For a temporary fix, Pete's instructions will help.

Assuming nothing wrong with the motor, I suspect the pole, true south direction, motor elevation, or dish elevation might be off.

When it gets warm, you will need to re-check all the above. Start with the pole and make sure it is plumb and solid. Check the motor elevation and make sure it is the same as your latitude. Verify the dish elevation. Then use USALS to move the dish to one of the satellites (use IA5 for example). If you don't get signal/quality, adjust the motor direction to True South.

More step by step instructions here.

 

[dogstar1313]

Thanks for all the great suggestions!

As I mentioned earlier, when I initially set my dish up it was dead on all across the arc using USALS and now USALS isn't even close. It doesn't appear to be elevation that's the problem. It's definitely azimuth as switching to 1.2 and bumping about five or six times west gets me right back to where it used to be with USALS. We had some wind gusts up around 50Mph a while back and it was soon after that that I noticed this problem, although it seems to be getting worse over time. I'm guessing that one of three things happened. Possibly the motor moved on the pole (since the dish can't move on the motor shaft because it is through bolted), the pole twisted in the mount, or the motor "jumped gears" and is out of calibration. For now I'll either set everything to 1.2 and tweak the positions or try fudging my longitude in the USALS setup as Pete mentioned. When the weather is a bit better I'll ascend the ladder and remedy it for good. Hopefully by that time I will have talked my wife into a 120cm dish upgrade so I can take care of that too while I have the ladder out.