Celestron Troubles !

[pat]

I just received my third 102mm slt scope (others had system failures).

This one seemed o.k. After placing the batteries in and setting the hand controller the alitude and azimuth responded correctly. Then I tried the Celestron cable. Pluging into the car and the scope. When I turned on the switch the azimuth automatically started moving more than half around before I turned it off.

The Celestron Tec. thought it was in the cable or where it is connected to the scope unit. The cable is nearly new and worked on the other two scopes. He is sending another. Does this sound like the problem? The scope later worked alright.

Another concern is that the hand controller display doesn't show the alignment star Denebula in Leo. This star is circled in the book as a star to use. Unfortunately this is the star I need for allignment. Shouldn't this be in the data base? Thanks, Pat

[rwilkey]

Hi Pat, do not know about cables and things, but for the star alignment, the hand-controller will pick different stars, whatever is best in the sky at the time of the alignment, Denebola is not the brightest star in the sky and an unusual choice, the book just gives that as an example. As long as you have set your time and location, the controller will pick the brightest stars in the sky, just follow thw directions and you will be fine.

[Cath]

Hi Pat

Not sure what is causing your main problems, but the handset will only list/show stars that are visible from your current location at the time. A lot of the stars on show during the summer night sky are different to the stars in the winter night sky, and it also depends where on the planet you happen to be at the time.

So you will find that the stars listed (and all other objects) in your handset will change through out the year.

[Cath]

Doh! Lol

[Demonperformer]

I have a 102slt.

Due to restricted visibility and too much LP, I tend to align using a two-part process. (a) either solar system or one-star (selecting the brightest star in the part of the sky I have available) and ( use GOTO to a second star of my choice from the LIST (option 8 - then scroll to 'named stars' rather than option 7, which requires an SAO number) and add that as a new alignment star. I find this works better for me than the 2-star align function. Works best when I spend the time to make sure the setup is level!

HTH

[pat]

I want to use the two star alignment (not the auto two star align). Where you are able to pick the stars you know from the list on the display. Which is also circled in the book. That is how I read it. I thought if you had this hand controller, maybe you would be able to check to see if this star is listed. Thanks, Pat

[Demonperformer]

I'm not actually acquainted with the book you are talking about, but Denebola is definitely a 'named star' on the handset. What time of day are you setting-up? The handset will only select alignment stars that are a certain level above the horizon (not sure exactly what that is) so if it is getting a bit low that may be a problem, but if it is above the horizon, it should still be findable on the 'named star' list. Basically, you can align on any two objects that you can 'GOTO' to from the handset, however you find them (caveat: never tried doing it with 'user defined' object, so that might not work), but the first one must be on the options the handset gives you on the align menu.

HTH

[pat]

Hi, Thanks

This star was clearly visable from my location in Ohio at 9pm. As was Arcturus. On the controller display it goes to Deneb then to a completely different named star. Looks like another call to Celestron. Pat

[Chris Rowland]

The alignment stars are selected from those that are above a lower and below an upper altitude limit. From Ohio Denebola may be above the upper limit (60 or 70 degrees). Use the scroll buttons (6 and 9) to choose another star. From what I can see you should have the choice between Castor, Pollux, Regulus, Alphard, Porrima, Spica, Arcturus (may be too high), Alphekka, Rasalgethi, Rasalhague and Vega. And Polaris of course.

Chris

[Demonperformer]

Hadn't thought about the upper limit. No idea of Ohio's latitude.

Just checked my mount. With Denebola 22d above the horizon atm, my list on "Two Star Align" from late-C to early-E goes:

Chort, Cor Caroli, Cursa, Denebola, Dubhe, Dziban, Edasich

so it is definitely there.

[pat]

Thanks, I also have restricted visibility. No northen sky. So first I'll try the one star method. Still have trouble with the tracking-too much drift. I changed the backlash to 20. I have been viewing the sun most if not all of the time.

I've gone to great pains to see that everything is set up and entered correctly. I just feel I'm missing something. Pat

[Chris Rowland]

I set CdC to what I guessed the latitude of Ohio was and set the time to a bit after sunset. Denebola was high, about 66 deg but the other stars were lower. I'm not sure how many of the stars I mentioned are in the alignment star list but Regulus Spica and Arcturus should be.

A one star or solar system alignment is a good way to start and it's possible to add or replace the alignment stars later if you want better pointing.

Chris

[Demonperformer]

Pat, if you are viewing the sun, are you changing the tracking rate (in MENU) to 'solar'? If not, that would produce significant drift.

And remember to switch it back again at night.

[Chris Rowland]

I wouldn't worry too much about the difference between the sidereal and solar tracking rates, it's about one degree a day. That's about the diameter of the Sun in 12 hours.

Chris

[pat]

Chris, Nice to know this. I had already changed it to solar rate. I was a little sloppy in setting the time and the bubble level was outside the black circle. All said, it did the best tracking ever. The only change was in changing the backlash to 20 on both axis. Pat