6 replies to this topic

[RocketScientist82]

I picked up a new 8" ACF LX90 in the big Orion/Meade blowout sale at High Point. Waiting for weather to give it first light, so for now just doing a lot of reading and planning and such. All my astronomy up to now has been fully 'manual', using an old EQ mount as a kid on my dad's telescope, and my everyday scope being a Dob (though it DOES have digital setting circles aka "push-to"), so this will be my first go-to/tracking style setup. Though I'm obviously familiar with the concept I've never actually used or lived with one, and a few details aren't really clear to me (and the manual hasn't been much help). So I figured I'd come to the experts here (I suspect youll be seeing a lot of me in this forum in coming days lol).

 

The main thing I'm trying to wrap my head around is operating the scope in 'manual' mode (moving the tube around by hand, with the clutches disengaged). If I'm NOT trying to find a specific target in the sky from the catalog, but rather just randomly hunting in the sky. Or if I'm trying to find something that's not listed in the catalog, is the expectation that you use the buttons on the hand-controller to slew the scope around? To me that sounds a bit awkward, and I'd much rather just disengage the clutches slightly and move the scope by hand like I'm used to. But if I do so, does this lose the star-alignment? Or are the encoders for the tube position separate from the drive gears, so that the computer tracks position even while in 'manual' mode (clutches disengaged)? Ideally you could align once, use the scope in tracking/go-to mode, loosen the clutches and manually hunt the sky if desired, re-engage the clutches and still have the computer know where you are pointed (so you can go right back to finding things from the catalog, track whatever you're looking at, etc etc). I just don't know if that's how the scope actually works? Or if you would need to repeat the star-alignment any time you disenaged the clutches and moved the scope?

 

Thanks in advance for any input! I can't friggin wait to get this bad boy out under these West Texas skies. You know what they say about them, deep in the heart of Texas hehe

Edited by RocketScientist82, 18 February 2025 - 07:00 PM.

[OzAndrewJ]

Gday RocketScientist82

 

But if I do so, does this lose the star-alignment?

Yep

The encoders are on the motors, not the axles.

Any releasing of the clutches to manually move will lose the alignment.

There is a trick you can use but it has some minor risks

but if you do an align first off, it sets the clocks etc correctly

as well as the align model for base tilt.

If you do release the clutches and move, the scope no longer knows where it is

but after rubbernecking manually, you can move to a known bright star and centre it using the handset.

Now, via the handset, scroll to it and select it using enter, but dont hit Goto

Now synch on the target and the scope will be realigned

For an LX90 with no hardstops this is OK, ,but for mounts with hardstops

it can upset the RA home datums.

 

Andrew Johansen Melbourne Australia

[RocketScientist82]

Thanks Andrew! That is what I sort of expected/feared. Would have been otherwise but ah well. Luckily with these mounts the alignment procedure seems pretty quick and painless, quite a bit less finnicky than my dob's push-to setup. So seems like it wont be a big burden to re-align if needed. I like your diea bout a quick re-align on a known star, I'll have to give that a try. I had a quetion about one item though:

Now, via the handset, scroll to it and select it using enter, but dont hit Goto

Now synch on the target and the scope will be realigned

 

What do you mean by "now synch on the target"? How does one do that, is there a button on the handset? If this will all be obvious once I get to actually go out and use the dang thing, apologies heh.

 

And greetings from t'other side of the world. I hope to make it down to your neck of the woods at some point to see all those southern constellations I've never laid eyes on.

[OzAndrewJ]

Gday RocketScientist82

 

What do you mean by "now synch on the target"?

You need to spend some time to read the manual and practice indoors ;-)

 

When you "select" a target in the handset, the system calculates its theoretical coordinates

( based on current encoder "datums" and align model )

When you hit <goto>, it moves the mount so the current encoder position matches the theoretical.

 

You can do this in reverse when you want to tweak positions

ie you "select" a target in the handset, the system calculates its theoretical coordinates

( based on current encoder "datums" and align model )

When you "synch" ( press and hold enter for several seconds ),

it adjusts the encoder datums so the new theoretical position matches the current encoder position.

 

Andrew Johansen Melbourne Australia

[RocketScientist82]

 

When you "synch" ( press and hold enter for several seconds ),

it adjusts the encoder datums so the new theoretical position matches the current encoder position.

 

This was the piece I was missing. I read through the manual twice last night, but must have missed the mention of this (there are a lot of sidebars and such though, so lots to digest). You mentioned practicing indoors, and I hadn;t thought about that. But no reason I couldnt "align" it inside (who cares how inaccurate) and practice navigating the handset, familiarize with how everything works etc. That way I wont waste valuable observing time once the weather clears. Thanks again for the help. Cheers!

[OzAndrewJ]

Gday RocketScientist82

 

There is an LX90 manual but there is also an Autostar manual

You need to read both

 

Andrew Johansen Melbourne Australia

[Sol_Survivor]

This was the piece I was missing. I read through the manual twice last night, but must have missed the mention of this (there are a lot of sidebars and such though, so lots to digest). You mentioned practicing indoors, and I hadn;t thought about that. But no reason I couldnt "align" it inside (who cares how inaccurate) and practice navigating the handset, familiarize with how everything works etc. That way I wont waste valuable observing time once the weather clears. Thanks again for the help. Cheers!

https://www.meadeuk....Controller.html

 

That's there as of right now.  In fact meadeuk is still up and operating and selling things a large discounts.   All scopes are gone except the X65.  They have some astro-camera's there for over %50 off as well.  I was going to load the .pdf for the AudioStar right in here but I can't seem to figure out how to upload a file here. 

 

The manuals are pretty dense with info.  I go back and read them several times each time I get stuck on a part that I know is in the manual. Still, there should be a book on in. Well there actually is on Amazon but its from 2010.  

So You Want a Meade LX Telescope!: How to Select and Use the LX200 and Other High-End Models (The Patrick Moore Practical Astronomy Series). Its really dedicated to the LX200 and LX400 Series though.

 

Edited by Sol_Survivor, 03 March 2025 - 10:24 AM.