LookingAbove
20-11-2016, 08:20 AM
I own a Meade LX600 telescope with StarLock. StarLock is Meade's fully autonomous guider, principally for astrophotography. When I started to experiment with astrophotography, I found that the StarLock was not working properly; the target star would quickly drift out of the FOV. I googled for a solution, and there were various suggestions; the drift alignment was off, the level of the telescope was off, the guide scope was out of focus.
After checking/correcting each of these possible issues I found that the target star would still drift very quickly out of the FOV. It seemed like the correcting signals being sent to the telescope were somehow corrupted and making the tracking worse than if there were no guider at all. As a result I was at the point of abandoning the StarLock and looking for a replacement.
By chance, I tried another google search, and found a post to a forum where a user had exactly the same issue with the StarLock as I. The user's name is Fabian Rodriguez from Perth, and he went all the way to solve the problem. Fabian has a Meade LX850 with StarLock and he contacted the Meade engineers, arranged a Skype session, and in the end they came up with a result. It turns out that the StarLock has a firmware problem. Even though the GPS knows that it is in the Southern Hemisphere, that detail isn't recognised by the StarLock, and as a result it drives the scope away from the target star until it is lost.
Every Meade telescope with StarLock in the Southern Hemisphere will suffer from this problem.
To their credit, Fabian and the Meade engineers devised a work-around that makes the StarLock work.
The work-around is:
- "Reverse L/R" should be on (Auto Star saves this setting),
- "Reverse U/D" should be on (AutoStar saves this setting),
- Change the "DEC. Guiding" from "North & South" to "North only" or "South only" (AutoStar does NOT save this setting, so you need to reset it for every session)
Note: Fabian uses "North only", while I find "South only" provides better guiding.
Fabian and the Meade engineers discovered this firmware problem in 2014; with the engineers saying that they would update the firmware; this has not yet happened!
Additionally, "training the drive" is necessary to ensure perfect tracking. There are two processes to achieve this, Periodic Error Correction (PEC), and Automatic Rate Calibration (ARC). These are both described in the Meade User Manual, however I would like to add some detail about the PEC training. It is advised to run the PEC training, then several iterations of the PEC update as well. The manual states that the PEC training takes 6.4 minutes. I have found that the PEC training takes 24 minutes, and one episode of the PEC updating takes 24 minutes as well. The ARC is relatively quick at four minutes.
You can monitor the corrections sent from the StarLock to the scope under "StarLock Status". There are two changing values displayed; the first is for RA the second is for Dec. Once the values for both vary between +2.0 and -2.0 then you are ready to take some photos!
PS - Many thanks to Fabian Rodriguez for all the assistance he has provided to me over the last month or so.
After checking/correcting each of these possible issues I found that the target star would still drift very quickly out of the FOV. It seemed like the correcting signals being sent to the telescope were somehow corrupted and making the tracking worse than if there were no guider at all. As a result I was at the point of abandoning the StarLock and looking for a replacement.
By chance, I tried another google search, and found a post to a forum where a user had exactly the same issue with the StarLock as I. The user's name is Fabian Rodriguez from Perth, and he went all the way to solve the problem. Fabian has a Meade LX850 with StarLock and he contacted the Meade engineers, arranged a Skype session, and in the end they came up with a result. It turns out that the StarLock has a firmware problem. Even though the GPS knows that it is in the Southern Hemisphere, that detail isn't recognised by the StarLock, and as a result it drives the scope away from the target star until it is lost.
Every Meade telescope with StarLock in the Southern Hemisphere will suffer from this problem.
To their credit, Fabian and the Meade engineers devised a work-around that makes the StarLock work.
The work-around is:
- "Reverse L/R" should be on (Auto Star saves this setting),
- "Reverse U/D" should be on (AutoStar saves this setting),
- Change the "DEC. Guiding" from "North & South" to "North only" or "South only" (AutoStar does NOT save this setting, so you need to reset it for every session)
Note: Fabian uses "North only", while I find "South only" provides better guiding.
Fabian and the Meade engineers discovered this firmware problem in 2014; with the engineers saying that they would update the firmware; this has not yet happened!
Additionally, "training the drive" is necessary to ensure perfect tracking. There are two processes to achieve this, Periodic Error Correction (PEC), and Automatic Rate Calibration (ARC). These are both described in the Meade User Manual, however I would like to add some detail about the PEC training. It is advised to run the PEC training, then several iterations of the PEC update as well. The manual states that the PEC training takes 6.4 minutes. I have found that the PEC training takes 24 minutes, and one episode of the PEC updating takes 24 minutes as well. The ARC is relatively quick at four minutes.
You can monitor the corrections sent from the StarLock to the scope under "StarLock Status". There are two changing values displayed; the first is for RA the second is for Dec. Once the values for both vary between +2.0 and -2.0 then you are ready to take some photos!
PS - Many thanks to Fabian Rodriguez for all the assistance he has provided to me over the last month or so.