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What to Do Next On Celestron SLT Problems?


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This is the 2nd 102mm slt scope. First one returned for electrical problems,second for grinding sound in moter. Both shipped back to Celestron at their expence.

The first time when it was turned on the scope started movement in "Asimuth"-no responce 17. Turned on, then back on. Worked fine. Tec. support said this may be a problem in the power cable from the car. New one sent. Both turned out fine after doing conductivity and voltage test.

Next the scope could not keep the sun in FOV for longer than 25 minutes. We exhausted all causes untill an engineer suggested polor aligning scope.

This is where you point and set the scope (and leg) at Polaris. Then put stakes in the ground so you can return it to the same position each day or night. Except I have a concrete driveway and no clear view of Polaris. The Tec. suggested a compass and set scope angle at 45*. After experimentation the sun stayed in the FOV for more than 1.5hrs. Drew a triangle around the legs and the tracking has worked. But if I want to move the scope to another location-you see the problem I have again. What a pain!

Is this normal? I can't see anything in the manual about this. And would not have bought this scope knowing this.

Before putting the scope away and moving it in Azimuth, it stopped-another No Responce 17. After quizzing the Tec. he said it had to do with the "alitude" motor. Try returning it to factory settings.

Any suggestions or help. Sorry this is so long-I'm at my witts end. Pat

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Yes,everything is set correctly. But it only works this way when it is polor alligned. Any other way the sun-moon drifts out of the FOV in 25 min. This has been tried in three differant power eyepieces where you can see the whole sun with a margin of space around it. You have to hold the hand controll to use the arrow buttons just to keep it in. It starts the drift almost right away. Half the sun has dissapeared in less than 15min. Pat

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As best I can see the scope has to be aligned using a star or two which during the day must lead to some inaccuracies.

Have you set the mount to Solar tracking from Sidereal ?

The sun moves at a different rate to the general stars, so if you are at sidereal then it will drift out.

What was the polar alignment? Magnetic or GPS ?

If you used a magnetic compass you could be well out before switching the scope on.

If you move the scope then yes you have to do the full realign again.

Considering that during the day you cannot centre stars for the scope to determine the errors and are not I suspect using the solar tracking rate and then the 102 is I think a Mak with a narrow field of view then 15-25 minutes is fairly good.

Edited by ronin
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The scope is set for solor tracking.The alignment is not GPS or totally magnetic. The only way is to position the OTA in the direction of Polasis. Then turn it on. And use the arrow buttons to move it to the sun. When finished move the scope back to its original position and turn off.

The manuel makes no mention of doing this. Just place the scope on the ground,enter the necessary information,center the sun then enter allign.

For this scope 25min. drift out of FOV is poor. Pat

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It sounds like an alignment problem. In order to get the mount right did you also check it was level?

Do not trust the Deg scale for declination, they are often out. I have bought a wee spirit level with a digital read out and use this to check the dec of the scope and set it correctly.

Use a compass to set north, BUT make sure you allow for magnetic variation. You do not indicate where you are. In the UK it can vary by 9 Deg (that is 18 moon diameters), here in Perth WA it is 1 deg, so a lot better.

Get a good lat and longitude for where you are from Google Earth.

Oh! and above all persist! EQ mounts were invented by people who want to drive other folk mad...at least that is how it seems when you first play with them.

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I have to agree with ronin 25 mins tracking on a solar align seems pretty decent considering you have no stars to align it to. As to power problems sometimes the connection from the lead into the socket is loose opening the pins inside the socket very gently with a screwdriver can tighten up the connection.

When you set up in other parts of the garden I assume you need a compass to align it to north do you have the correct magnetic variance for your area as you will need to add or subtract this from your compass reading and don't forget magnetic north isnt the same as celestial north so you will need to compensate for that as well

This should help you find the magnetic declination for your area

http://www.threelittlemaids.co.uk/magdec/index1.html

Edited by rowan46
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Pat, I had this concern and managed to fix it purely by trial & error so it may work for you. Please forgive the style I am writing this in as the enter key on my notepad does not work in this forum for some reason. --------------- OK here we go. ----------- Align your scope as you normally would. --------- Then instead of selecting the object you want to track from the usual buttons on the handset use the "Goto RA & DEC" option to find any other object ( you will find this option by pressing the " menu" key on the handset and then using the scroll keys) -------------- Then use the "Goto RA & Dec" option again to return the object you wanted to track originally or any other object you want track.---------- I found this method of finding and tracking objects works much better :laugh: ------------ Stellarium shows the coordinates for RA & DEC. I hope it works for you :grin:

Edited by Pig
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Hi, Sorry I have't been back on line to answer some of your questions and help. Thanks. I'm in Ohio USA.

The level bubble and mount level has been tested and is ok

Not an EQ mount.

Lat. and Long. is set by Google.

Been working with Tec. for slow drift problem. This is solved when polar alligning scope each time it is set up. This has become a problem, as mentioned before.

The power supply, car cable mount pin ect. has been rulled out as a cause.

Not familar with setting slt Goto to RA and Dec.-have to bring this up with Tec.

I hope I didn't miss any thing. If so please let me know. Thanks, Pat

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So I assume you have been doing this

Solar System Align

Solar System Align is designed to provide excellent tracking and GoTo performance by using solar system objects

(Sun, Moon and planets) to align the telescope with the sky. Solar System Align is a great way to align your telescope

for daytime viewing as well as a quick way to align the telescope for night time observing.

Never look directly at the sun with the naked eye or with a telescope (unless you have the proper solar

filter). Permanent and irreversible eye damage may result.

1. Select Solar System Align from the alignment options.

2. Press ENTER to accept the time/site information displayed on the display, or press UNDO to enter new

information.

3. The SELECT OBJECT message will appear in the top row of the display. Use the Up and Down scroll keys

(10) to select the daytime object (planet, moon or sun) you wish to align. Press ENTER.

4. NexStar then asks you to center in the eyepiece the alignment object you selected. Use the direction arrow

buttons to slew the telescope to the alignment object and carefully center it in the finderscope. Press ENTER

when centered.

5. Then, center the object in the eyepiece and press ALIGN.

Once in position, the NexStar will model the sky based on this information and display Align Successful.

Tips for Using Solar System Align

 For safety purposes, the Sun will not be displayed in any of the hand control’s customer object lists unless it

is enabled from the Utilities Menu. To allow the Sun to be displayed on the hand control, do the following:

1. Press the UNDO button until the display reads “NexStar SLT”

2. Press the MENU button and use the Up and Down keys to select the Utilities menu. Press ENTER.

3. Use the UP and Down keys to select Sun Menu and press ENTER.

4. Press ENTER again to allow the Sun to appear on the hand control display.

The Sun can be removed from the display by using the same procedure as above.

To improve the telescope pointing accuracy, you can use the Re-Align feature as described below

your time setting needs to be fairly accurate if you are using sun align

also are you entering the gps correctlythere are 2 coordinate formats one is decimal which I believe is the one that celestron doesn't use It seems that google uses decimals as do most gps receivers you may need to convert to standard coordinates

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Hi Pat,

Sorry to hear that you're running into problems with the SLT mount. I have the Celestron 127 Mak SLT package and can confirm that when set up it can track the Sun/moon for 2+ hours on a solar system align. Even when just using AA batteries.

Could you confirm the setup routine (as the post above) and all the data you are entering on setup?

Also are you setting the tracking rate to solar/lunar (I think you said you are but tapatalk doesn't let me check the posts when creating one!)

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Pat didn't mention any sort of alignment at all, just point OTA towards Polaris, turn it on and manually move to the Sun. If that's the case I'm surprised that it's even tracking. A one star alignment on Polaris might get it tracking but as the position of Polaris has only been estimated by compass and moving the OTA it isn't going to be accurate.

A better way to get going would be to do a Solar System align on the Sun. Errors in levelling, time and position will affect how long it will track but an alignment using a real celestial object will be better than guessing where Polaris is.

Chris

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Rowan, All your steps are followed correctly ,except the tip on re-alignment. The scope does not come with GPS.

The tracking rate is set correct for either the sun or moon.

Chris, I go to the solar system align(doing the steps above) after the "polar align" is set up first, this gives me good results.

"Polar align" might mean something differant in the way you set up you scopes. The Celestron engineer just used this word.

No EQ or wedge,the NexStar slt series are exculusively Alt-Az mounted scopes. As the manuel says.

The Tec. finally had me change the hand cotroller back to the factory settings. Then re-enter the data. Same results.

One thing I didn't mention, is when viewing the sun in the East, it drifts towards the top. Just the opposite when viewing the sun in the West. Pat

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pat do you convert google earths decimal coordinates to standard coordinates I don't know how much difference it makes but it may make some difference the nexstar uses standard coordinates rather than decimal

http://support.googl...&answer=2533464 also nexstars like to be centred from If I remember correctly right and up to take account of the inherent backlash in the system check nexstar users site

http://www.nexstarsite.com/NUG.htm

Edited by rowan46
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"Polar Align" is confusing because it's something that's done with equatorially mounted scopes, not Alt Az. Still, we know what you are doing now.

The scope has to know two directions to be able to find and track objects. For the one object alignments (One Star and Solar System) the mount assumes that the mount is level and the position and time is correct. It's difficult to do this with a level, especially the small bubble level on some scopes. A builder's level across the tripod may help.

Chris

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I do the best I can with the small level I have. The top of the mount is dome shaped. Also tried using the tray as a platform.

I don't use decimal coordinates. If that is what you mean. Three differant close areas around here have been tried. And entered in the hand controller. These don't change the drift time.

I would assume that entering the Suns RA and DEC on this mount woulnn't work (if I could do so). Is that the correct thinging?

So far I think,with your help, I can come up with some other questions for the Tec. I've been working with for about two weeks.

I would like him to say, you can't expect the Sun to stay in the FOV longer than 25mins. That would put a limit on the scopes capibility.

I can't but think it's a motor problem. Or the scope needs two referance points. Pat

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The SLT scopes are on Alt-Azimuth mounts. The way these work are that they mimic the arc motions of the sky in small steps of Up-Down-Left Right. Given that you actually got 1.5hrs of tracking the sun with it Polar aligned, thats awesome!

What I believe is that you are asking for more than the scope can deliver. The SLT scopes have plastic flimsy mounts and are for the casual user. You can retain the optical tube and get yourself a small equatorial mount like the Smart EQ or EQ3-PRO or something. As far as aligning the tripod everytime is concerned, welcome to the group mate! Everyone who lacks a permanent observatory has t do it everytime regardless of the size of the scope. I have to lug 200 Lbs of equipment everytime to my rooftop even now. I have always considered a permanent pier on the roof, but things take time.

As far as the accuracy of the latitude and longitude are concerned, they dont make much difference of you put the decimals in or not. This is because the Sun is 150Mil Kms away and the decimals in your Lat. Long simply make a difference of a few meters at most. :)

RA and DEC are for EQ mount, yours is Alt-Az, they wont help either.

Perseverance is the key to success, but where you persevere depends on The Path you choose. Currently as I see it, you are using an Alt-Az scope for EQ applications, which is the incorrect thing, but do ask around, join a club where you get to see others with scopes, use them, nothing beats that. Go to star parties like Kelling Heath, or Peak Star Party etc, they help immensely.

Hope this helps,

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Thanks, I had been under the impression that all that was needed was too use the manuel instructions and what Rowan46 reiterrated. For the scope to track over a longer period of time.

The Polar align is a new twist I didn't expect.

And as said it's quess work mostly for Polar align. But without it, the moon also moves out of of FOV. Moon rate is entered.

It would be nice to have a group nearby. But I have to relay on you guys for help. I still need to get the scope out on a clear moonless night to test it on sideral time. Pat

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Thanks, I had been under the impression that all that was needed was too use the manuel instructions and what Rowan46 reiterrated. For the scope to track over a longer period of time.

The Polar align is a new twist I didn't expect.

And as said it's quess work mostly for Polar align. But without it, the moon also moves out of of FOV. Moon rate is entered.

It would be nice to have a group nearby. But I have to relay on you guys for help. I still need to get the scope out on a clear moonless night to test it on sideral time. Pat

Pat, your impression is absolutely correct. A simple solar system align should allow you to keep a target in the field of view of a 26mm eyepiece for hours without it drifting out fully.

I do not know why you have been advised to do a polar align by Celestron, as my understanding is that it is a completely meaningless exercise with the mount you have. There is no 'north leg' to the mount like there is with an EQ mount. Neither does the software on the control record the position it starts up at. The control uses the Lat/Long coordinates, the time and timezone and the alignment process to build a model of how targets should be moving in night sky.

Are you entering the data in the following way?

Latitude: 51d 31' 12" North (this is an example for London)

Longitude: 0d 6' 0" West (this is an example for London)

Time: The time now is 19:23 so I would specify either

19:23:00 - Daylight savings - TImezone: 0

or

18:23:00 - Standard Time - Timezone: 0

Date: 22/06/2013

It's worth double checking this, I know several people who have mixed up the Lat/Long or time settings and ended up with poor tracking. Other than this the only other area for error is in the alignment process itself.

It would be helpful to us for you to tell us exactly what data you are entering.

Damien

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troduced with NexStar hand control version 4 (first included with the CPC) and available in all newer versions, Solar System Align is available in alt-az mode (scope mounted directly on the tripod) and equatorial mode (scope mounted on a wedge). Solar System Align is designed to provide excellent tracking and GoTo performance during daytime use. Now you will be able to actually GoTo the Sun (with appropriate filter), Moon, planets and bright stars for daytime viewing.

Procedure:

  • Power up the scope.
  • Press ENTER to begin, use the Up and Down buttons (6 and 9 on the keypad) to scroll to Solar Sys.Align and then ENTER again.
  • The hand control will show either the current time or the time when you last used the scope. The top line of the display will cycle through the messages, "Enter if OK", and "UNDO to edit". If your scope has a GPS module, the GPS receiver will shortly lock onto 3 GPS satellites and update the date, time, and location. If you become impatient waiting for a GPS link, or if you don't have a GPS module in your scope, use the Up and Down buttons (6 and 9 on the keypad) to scroll through the date, time, and location settings. If they are all correct, press Enter to accept and proceed with the alignment. If they need adjusted, press Undo and make any necessary corrections.
  • The display will now prompt to Select Object. By pressing the Up and Down buttons (6 and 9 on the keypad) you can select from the Sun, Moon or planets that are currently between 15 and 70 degrees above the horizon. Note that to include the Sun in the list, you must first access the Menu button (UNDO back to the "Press ENTER to begin alignment" prompt), select Utilities and then Sun Menu. This is a one-time setting and will be stored for future use. Note that you must have a safe solar filter or cap the scope and use a "sun finder" to safely use the Sun as an alignment object!
  • After you press ENTER to select the solar system object you wish to use for alignment, use the arrow buttons to slew (move) to the that object. Center the object in the finderscope and press ENTER. Then center the object in the eyepiece and press ALIGN.
  • If you are only interested in viewing the object you aligned on, you are finished. If you would like accurate GoTo and tracking that to view other objects, continue with the next step - you may be surprised how easily planets and bright stars are to see in the eyepiece during the day!
  • To provide accurate GoTo and tracking across the sky, use the hand control's normal GoTo for any object that can be seen in the daylight and use the NexStar Re-Alignment feature to replace the "Unassigned" star with that object.

Additional details:

  • As with all the new NexStar alignment methods, Solar System Align does not care where the optical tube is pointed at the beginning of the alignment.
  • To get better tracking and more accurate GoTo while still relying on a single alignment point, be sure to level the tripod before you start.
  • If you do not have a GPS-equipped telescope, be accurate to within a couple of minutes when entering the time. Also, either select a city within 50 miles or enter your longitude and latitude to within a degree or two.
  • If you use Re-Alignment to replace the unassigned star, you may not use the same object you aligned on originally. In other words, if you first alignment on Jupiter, you cannot replace the "Unassigned" star with Jupiter.
  • Be sure to center the objects with the same final movements as the direction of the GoTo Approach. For example, if the scope normally finishes a GoTo with the front of the scope moving right and up, you will center all three objects in the eyepiece with the right and down arrow buttons (the up/down arrows reverse at slew rates of 6 or lower). For more details on this, refer to my book The NexStar User's Guide or the other general alignment guides found here on my web site



  • I don't know if theres anything new here for you
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  • As with all the new NexStar alignment methods, Solar System Align does not care where the optical tube is pointed at the beginning of the alignment.

So clearly the Celestron tech advising Pat is talking out of his rear, as I thought!

I don't think there is much more we can do to help Pat until we can confirm the data he is inputting is correct.

Damien

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I believe that all the input data is correct. This is the 2nd scope, because of problems with the others.I've spent time going over about every scenario with the Tec. on this scope.

The time can either be military or local.Local Daylight Saveing time is used. Entered as HH+min+ss.

Date: mm/dd/yy

Long. 82* 58' 38" W

Lat. +38 47' 18" N

From your reply It sounds as if "they' are graphing for straws.

As mentioned earlier I've had two of the same error messages show up on the hand controler. This error number controls the alt. motor, I was told. Although the motor was moving in azt. But was then told it didn't effect tracking?

Mixed signals, maybe.

I agree the sun should stay in the eyepiece and stick with my instruction manuel.

Or the Tec. wouldn't be suggesting other solutions or remedies.

Maybe you have other suggestions what I should do next? Thanks, Pat

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I believe that all the input data is correct. This is the 2nd scope, because of problems with the others.I've spent time going over about every scenario with the Tec. on this scope.

The time can either be military or local.Local Daylight Saveing time is used. Entered as HH+min+ss.

Date: mm/dd/yy

Long. 82* 58' 38" W

Lat. +38 47' 18" N

From your reply It sounds as if "they' are graphing for straws.

As mentioned earlier I've had two of the same error messages show up on the hand controler. This error number controls the alt. motor, I was told. Although the motor was moving in azt. But was then told it didn't effect tracking?

Mixed signals, maybe.

I agree the sun should stay in the eyepiece and stick with my instruction manuel.

Or the Tec. wouldn't be suggesting other solutions or remedies.

Maybe you have other suggestions what I should do next? Thanks, Pat

If its broken send it back and get a new one its under guarentee isnt it? I dont know what the american law is on goods which dont work over here if we can prove its not fit for purpose we can demand a replacement in some countries I believe its at the companys discretion whether to repair or replace
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