Re: MACH1 GTO Merdian Flip #Keypad

Roland Christen

Meridian delay does not perform a meridian flip. Those are two different things. Normally the mount will continue to track past the meridian (overhead point) until you send a GoTo. Then it will flip sides. The mount can also be set up to stop tracking at the meridian by setting the limits.

If the mount does not flip when you issue a GoTo after it has passed the meridian, then it is highly likely that the clock time is set wrong. The meridian is calculated from your local time/date/location. In the keypad main Menu pressing 4 = Time/LST will bring up your local time and LST which is the calculated Meridian Right Ascension value. (LST = Local Sidereal Time). That RA value is the point where the mount will flip sides when a GoTo is issued. So, that is a check on the operation of the mount that you need to be familiar with. Simply compare the calculated value and compare it to where your planetarium program says the meridian is. Also check the local clock time to make sure it is not set to the wrong value. Clock time is shown as military time (example 1pm = 1300 hours).


-----Original Message-----
From: Ken M <kmurfitt@...>
Sent: Thu, Jul 23, 2020 12:20 pm
Subject: [ap-gto] MACH1 GTO Merdian Flip #Keypad


While imaging the Crescent Nebula a few nights back, I rang into a snag when attempting a meridian flip from the Keypad.
I tried to perform a meridian flip from the Keypad by setting RA/DEC/REV -> Meridian 2E, 1E, 0W, 1W, 2W in that order. Each time I attempted to
"re-go to" the Crescent nebula but the mount would not perform a merdian flip.
The scope was almost upright on the West side - well within the hour of passing the meridian.
I used the Tour -> Common Object Names to select the Crescent nebula. I later tried selecting NGC 6888 directly but the mount would not flip.
The Keypad Mount Type is set to MACH1.
Auto-Connect is set to EXT - my setup connects with Stellarium.
All other operations between the keypad, Stellarium, PHD2 and the mount seemed to be working fine.

The Keypad is relatively new (2018 model - firmware rev 4.19.3) and so I don't suspect the battery is the problem - I get no 'symptoms' of low battery ("object below horizon" etc).

Any thoughts on how to achieve a meridian flip from the Keypad please? Should I have set something from the Astro-Physics driver instead?
Eventually I slewed the mount manually to perform the "flip".
Thanks for any pointers.

Join to automatically receive all group messages.