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Pages: 1 WillieS member Reged: 07/23/07 Loc: Central Texas GPS problem with my CPC1100       #5740039 - 03/18/13 03:12 AM Edit   Reply   Quote Quick Reply   I have had this scope for about 5 years now. I live in central Texas, currently UTC-5. I have had my scope powered on & plugged in for the better part of 4 days now. It was actually on for 36 hours at one point. I never get a GPS fix and the time is always off by close to 2 hours if I havent used it for awhile. Now that it has been on for awhile, the time will usually be off by about 15 minutes. I always was impatient and just input my coordinates, date, time on my own and things worked well. I upgraded my hand paddle about 4 days ago to the latest version and now I cannot find a place to manually enter my lat/lon. I can change the date, time, time zone, but not the location. If I check the location, it indicates that I am in a saved location of 33:50:41 lat & -118:20:17 long. The date will always indicate February of 2004. I dont remember the exact date. Does this sound like a GPS battery issue? I am using the Celestron power supply that I got from OPT recently. My original power supply failed about 6 months ago. I am almost always setup on the same location at our observing site with about 330 degrees of unobstructed view. Thanks, Willie Post Extras:       dragonslayer1 sage Reged: 02/25/12 Loc: SLC, UT Re: GPS problem with my CPC1100 [Re: WillieS]       #5740825 - 03/18/13 02:28 PM Edit   Reply   Quote Quick Reply   From someone that just upgraded to new hand control, I had to reflash motor to latest (5.14?) version and reflash hand control as well even tho it was new Kasey Post Extras:       sanlopez sage Reged: 12/03/07 Loc: 35.9606° N, 83.9208° W Re: GPS problem with my CPC1100 [Re: dragonslayer1]       #5741705 - 03/18/13 08:46 PM Edit   Reply   Quote Quick Reply   Have you checked to see if your GPS is on? It's part of the set-up menu. Post Extras:       jerwin professor emeritus Reged: 05/17/12 Loc: Romeoville IL Re: GPS problem with my CPC1100 [Re: sanlopez]       #5741759 - 03/18/13 09:07 PM Edit   Reply   Quote Quick Reply   I've set my CPC1100 up at a dark site a few times and I don't know what it is about that site, but my GPS always times out and it turns itself off. I can take it home or to my other dark site and it works fine, so I'd suggest you double check it's on. Good luck and clear skies, Jim Post Extras:       rmollise Postmaster Reged: 07/06/07 Re: GPS problem with my CPC1100 [Re: jerwin]       #5742483 - 03/19/13 09:19 AM Edit   Reply   Quote Quick Reply   The battery won't help. A totally dead battery only means the receiver will have to download an almanac from the SVs. It will get a fix, it will just take longer. A dead battery in my NS GPS means it might take 45-seconds to get a fix...and with the weather we've had the last year or two, the battery is often dead. Suggestions? If the scope hasn't been opened, the first thing to do is do a reset to factory values, re-enter all the vital information, set up in an open, clear area and see if it will get a fix. If it doesn't get one in a minute or three, there is a problem with the receiver, the antenna, or the connections. Oh...and where has your scope been setup? The receiver will NEVER get a fix indoors. Edited by rmollise (03/19/13 09:20 AM) Post Extras:       Edward E professor emeritus Reged: 03/26/06 Loc: Tucson, Arizona Re: GPS problem with my CPC1100 [Re: WillieS]       #5742924 - 03/19/13 01:10 PM Edit   Reply   Quote Quick Reply   Just from my own, recent experience with a C11 GPS vs2 scope using a new HC (vs 4.18), when my GPS battery died it would take several minutes before the scope locked on to the GPS sats, then after a 3 star alignment the scope could locate and an object but the tracking was bad, after 30 minutes of use, the scope could not point accurately. After I replaced the GPS battery and allowed the scope to charge the battery for 48 hrs, with out making any adjustments to the HC settings, the time to lock on to GPS sats was very fast, after an alignment (even just a quick moon alignment) pointing was dead-on even after 3 hrs of use and tracking was back to excellent. So, for me, it was worth changing the GPS battery. I think the newer CPC models have the GPS battery soldered to the GPS module so it may not be an easily fix as with the some of the older GPS models. Post Extras:       rmollise Postmaster Reged: 07/06/07 Re: GPS problem with my CPC1100 [Re: Edward E]       #5743056 - 03/19/13 02:08 PM Edit   Reply   Quote Quick Reply   I know that was what you experienced, but believe me, the GPS did not affect tracking. GPS is used for time and position. If those are correct and you do a good alignment...all is well. Post Extras:       Edward E professor emeritus Reged: 03/26/06 Loc: Tucson, Arizona Re: GPS problem with my CPC1100 [Re: rmollise]       #5743462 - 03/19/13 05:04 PM Edit   Reply   Quote Quick Reply   I agree Uncle Rod, GPS does not affect tracking. Tracking and pointing accuracy are dependent on accurate date and time. The battery, in addition to maintain the sat ephemerides, also maintains the scopes internal date/time after an alignment, at least with the older NexStar GPS units. No battery, no accurately maintained internal time, degrading pointing and tracking over a short period of time. Post Extras:       rmollise Postmaster Reged: 07/06/07 Re: GPS problem with my CPC1100 [Re: Edward E]       #5743627 - 03/19/13 06:07 PM Edit   Reply   Quote Quick Reply   With the scope turned off, time might get off. But once you power it up and get a fix, time will be right again sooo...the battery really cannot affect tracking. Not that it would really affect tracking in anyway. Tracking is dependent on _alignment_. As long as the scope knows its current altitude and azimuth, tracking will be just fine. Time doesn't enter into it at all. Post Extras:       Peter in Reno Post Laureate Reged: 07/15/08 Loc: Reno, NV Re: GPS problem with my CPC1100 [Re: rmollise]       #5743636 - 03/19/13 06:13 PM Edit   Reply   Quote Quick Reply   Doesn't time affect GoTo accuracy? If the time is off, how will it perform accurate GoTo? It is correct that the mount does not care about current time during tracking but it might care for next GoTo. Simply set the correct date/time every time you power on the scope and double check location (Lat/Long) and you should be fine. Peter Post Extras:       rmollise Postmaster Reged: 07/06/07 Re: GPS problem with my CPC1100 [Re: Peter in Reno]       #5743690 - 03/19/13 06:40 PM Edit   Reply   Quote Quick Reply   Quote: Doesn't time affect GoTo accuracy? If the time is off, how will it perform accurate GoTo? It is correct that the mount does not care about current time during tracking but it might care for next GoTo. Simply set the correct date/time every time you power on the scope and double check location (Lat/Long) and you should be fine. Peter Time does not affect go-tos. EXCEPT to planets. If time is GROSSLY off, a planet might be missed, but it will have to be days and days off, not minutes. Again, what matters for tracking is alignment, and that's mostly true of go-to too. Post Extras:       Peter in Reno Post Laureate Reged: 07/15/08 Loc: Reno, NV Re: GPS problem with my CPC1100 [Re: rmollise]       #5743755 - 03/19/13 07:01 PM Edit   Reply   Quote Quick Reply   Then what is the GoTo based on? So after successfull star alignments, it must use relative time instead of absolute time. In other words, it probably calculates the time difference between the new GoTo and current location which probably makes sense that the internal time does not matter. Astro-Physics mounts do the same thing by using relative to current position. Peter Post Extras:       mclewis1 Thread Killer Reged: 02/25/06 Loc: New Brunswick, Canada Re: GPS problem with my CPC1100 [Re: Peter in Reno]       #5743787 - 03/19/13 07:10 PM Edit   Reply   Quote Quick Reply   First when discussing goto accuracy we need to differentiate between DSO and solar system tracking and pointing capabilities. The tracking and pointing accuracy of DSOs is dependent on accurate sidereal time and location. Solar system tracking and pointing accuracy is dependent on accurate local "civil" time and location. The tracking of and pointing accuracy to DSOs is only dependent on how well the initial alignment is done (good choice of stars, accurately centered). The local time and date does not affect that. The software in the micro controller (in the HC) maintains local sidereal time (LST) which is derived from the initial alignment and not calculated off of local time ... a real time clock is only a convenience. An accurate user inputted or GPS derived local or civil time/date/position is important for a) pointing to and selection/filtering of the initial alignment stars and b) tracking of and pointing to solar system objects. Post Extras:       Edward E professor emeritus Reged: 03/26/06 Loc: Tucson, Arizona Re: GPS problem with my CPC1100 [Re: mclewis1]       #5745099 - 03/20/13 01:00 PM Edit   Reply   Quote Quick Reply   So the the verdict is that the GPS battery has no bearing on the functioning of the scope outside of maintaining the sat ephemeris/faster link with GPS sats. It's ok to have a dead and/or no battery on the GPS module since it only results in slower GPS link; correct? Post Extras:       Pages: 1

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