Nexstar Filter limits

[Patbloke]

Hi everyone,

I have tried to find an answer as to why I have just started getting a message on my Celestron Nexstar hand controller on my Advanced GT mount stating -

Filter warning! Database does not contain any objects within the filter limits... It then directs me to the menu, scope set up to re adjust the filter limits...

at the moment they show Alt max 90, list Alt min +00

I get the warning when I try to align the first star on two star alignment. 

Can anyone help please? 

Thanks Pat

[Gazabone]

Might it be a problem using a handset for an altaz mount on an EQ one?

[ronin]

Sounds like something is wrong in the data, have you altered anything before it began?

You haven't started entering he date in UK format have you and not US.

I am assuming that the location has not been altered.

One odd thing to do is change the Min and Max to something, say +1 (Min) and +89 (Max).

MAybe whatever the defaults are supposed to be have gone a bit nuts and giving them a newly defined value could/would clear out the junk and they work happily. I had this on something a few months ago in a different area, not astro.

The other is to check the data throughout. Basically it sounds like the date or time is incorrect so all stars are below the horizon.

Is time is AM/PM format or 24 hour format, just wondering if you have managed to tell it that it is 8:00 AM not 8:00 PM

Which version of the software is present, I think on the Synscan V3.26 had a problem with timezone, the mount altered what was entered. No idea is the fault occurred on any Celestron units however.

Check the mount is as you expect, Alt/Az or EQ. If that has changed from Alt/Az to EQ then many stars will be below the +00 limit as far as the mount is concerned.

[Gazabone]

..... Also, check the location. I had to force a location change on one of my mounts last year. I did the align and had it pointing to stars etc fairly well but when I asked it to goto Jupiter it was (my estimate) about 30 deg out. When I managed to get into the location settings, it was somewhere in the U.S. I'm in Cornwall, UK! Once I got that sorted, it all started behaving itself.

[ronin]

Strange as the manual implies that the filter limits only come into effect when the alignment is complete, although that seems a little incorrect as it has a location and time so should be able to determine if something is more or less above the horizon.

The manual says:

If you want to explore the entire object database, set the maximum altitude limit to 90º and the minimum limit to –90º. This will display every object in the database lists regardless of whether it is visible in the sky from your location.

Hate ask this but you did set (custom location) or pick Birmingham UK, not Birmingham Alabama ?

[Patbloke]

Thanks for the advice... Sorry I posted then had a mega phone call!

OK, so I checked the date format, location and they were correct... I have however changed the limits to 90 and -90 and attempted three star alignment indoors and success! Is there a setting to change from EQ to Alt/Az?

I guess I need to try it a few more times then go outside when those clouds disappear and give it the real night experience.

I'll keep you posted, but once again I bow to your wisdom and thanks for the help so far...

Sent from my SM-T700 using Tapatalk

[Patbloke]

I was actually using the mount the other night when this warning occurred out of the blue... Never had an issue with it before but since your advice, it has aligned successfully three times indoors... It will be interesting to see if it gets close to where the targets are next use outside, because if I remember correctly it was way out when I started to set it up the night the warning appeared.

I have updated the software on this set before and until the other night it's performed very well.

The thing is without your help I would still have the issue... Great forum, knowledgeable members!

Sent from my SM-T700 using Tapatalk

[Patbloke]

Latest and final update - I hope :-)

I have reset factory settings on handset as when aligning (albeit indoors) I could see that the scope was quite a way out from pointing to the stars it should be (I used Google star map on my tablet to get a rough location) Since the reset it looks like its getting really close to the alignment stars... It's looking good now and the filter settings have reverted to 90 and +00 guess that's where we started but looks ok now. I set Birmingham England.

I love this mount, it was second hand, but with with the C8 XLT OTA on it, I think I bagged a bargain... It's a steady as a rock.

[ronin]

You are on an EQ mount and the handset should talk to the mount and know what it is.

The problem could arise if the mount was Alt/Az (like the 4/5/6/8 SE mounts) and the whole lot was placed on a wedge or platform.

That way the mount is saying it is an Alt/Az but the setup is EQ. In which case you need to be able to override the Alt/Az aspect. It will not occur on an EQ (I think).

Asked about Birmingham as one person managed to get the wrong one, damn did that cause a problem. :grin:

What may have occurred is that the value in the Max changed to -90 = change of sign.

Then the position would have to be both less then -90 and more then 0, and that is not possible, so it would report no valid stars in the filter limits. That is likely the simplest explanation, or the minimum value became corrupted and was now greater then 90, so again the position needed to be both greater then 90 and less then 90 simultanuously. I wonder if there is a difference between +0 and -0, I know one of the Meades I have needs the time zone as -0, not 0 which is I guess +0. I have no idea why.

[Patbloke]

It was strange that when I got it to align before reset without a warning, the scope was aiming not quite in the right direction of alignment stars...

Following reset it looks good. I just need to try it outside now. I'll post a report on performance.

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