Giving up on EQMOD

[tooth_dr]

4 minutes ago, david_taurus83 said:

Hope all goes to plan next time your out!

Thanks for all your help, and everyone else who contributed above. To shut down do I just park then what..

[kens]

7 hours ago, tooth_dr said:

All these programmes seem to giving the same coordinates.

why does it give a reading of 15deg R.A. when at home. Shouldn’t this be 0?

In the home position (poiting at the pole, counterweights vertical and down) the RA should be LST +/- 6 hours. +6 hours is to the east of the pole. -6 hours is to the west. When RA equals LST you are pointing at the meridian.

[tooth_dr]

15 minutes ago, kens said:

In the home position (poiting at the pole, counterweights vertical and down) the RA should be LST +/- 6 hours. +6 hours is to the east of the pole. -6 hours is to the west. When RA equals LST you are pointing at the meridian.

LST I had to google = local sidereal time.

Then I came across the Julian Day = the number of days since noon at Greenwich on 1 Jan 4713 BC!

RA must equal LST if you are pointed at meridian? And is the meridian at the NCP or aka home position?

 

[kens]

49 minutes ago, tooth_dr said:

LST I had to google = local sidereal time.

Then I came across the Julian Day = the number of days since noon at Greenwich on 1 Jan 4713 BC!

RA must equal LST if you are pointed at meridian? And is the meridian at the NCP or aka home position?

 

You'll also see that the first number on the EQMOD screen is LST - just above RA. LST is simply an indication of the position of the earth in relation to the stars. The meridian is the line that connects the north and south poles and passes directly overhead. So LST tells you what the RA is for stars along that line.

The meridian is most certainly not associated with the home position. Look at your scope in the home position. Now rotate it in declination. Note that moving in declination moves you along the lines that connect the poles. See how it moves east and west? So in the home position you are aligned 90 degrees (or 6 hours) from the meridian.

To move along the meridian you need to rotate in RA till your counterweight shaft is horizontal.  Then moving in declination follows the meridian. And if you rotate in RA a little further past the meridian so the counterweights are above the horizontal your scope will eventually hit the tripod (if you have a GEM). That's why you do a meridian flip.

[tooth_dr]

9 hours ago, kens said:

The meridian is most certainly not associated with the home position. Look at your scope in the home position. Now rotate it in declination. Note that moving in declination moves you along the lines that connect the poles. See how it moves east and west? So in the home position you are aligned 90 degrees (or 6 hours) from the meridian.

 

I’m confused, I thought the meridian ran through the NCP and that’s where my scope should be pointing in home position.  I understand that the scope won’t move along the meridian in that position but I meant does it not point at the meridian at home?

[Anthonyexmouth]

Just now, tooth_dr said:

 

I’m confused, I thought the meridian ran through the NCP and that’s where my scope should be pointing in home position. 

It does, but the meridian isn't RA . The meridian is directly overhead in relation to your point on earth, RA is a position on the celestial sphere

[tooth_dr]

54 minutes ago, Anthonyexmouth said:

It does, but the meridian isn't RA . The meridian is directly overhead in relation to your point on earth, RA is a position on the celestial sphere

Yes I see now! RA at the meridian will move by 4 minutes each day for the same clock time.  So RA can be zero at the meridian but only once per year, on the spring equinox?

[Anthonyexmouth]

3 minutes ago, tooth_dr said:

Yes I see now! RA at the meridian will move by 4 minutes each day for the same clock time.  So RA can be zero at the meridian but only once per year, on the spring equinox?

no, RA is rotating once a day as the earth spins. RA is zero at your meridian once a day. 

[Big Jim Slade]

Think of RA like the longitude lines on a globe, but drawn on the celestial sphere. So as the sky rotates, RA moves with it. 

[tooth_dr]

I have all up and running. I did a random slew to the moon about 30 minutes ago from ‘home’ position.

I let it just track away there whilst configuring a few things. I just opened up PHD2 there and this was in the FOV ??

Hope it’s at least a little clear tonight. 

[michaelmorris]

Perhaps the problem is trying to plate solve on the pole.  Have you tried slewing to a star some distance from the pole and plate solving on that instead?

[tooth_dr]

15 minutes ago, michaelmorris said:

Perhaps the problem is trying to plate solve on the pole.  Have you tried slewing to a star some distance from the pole and plate solving on that instead?

This never worked before. Only if I solved at the Pole would it work! 

Typical plate solves were around 45-75s.

However, since setting up EQMOD my plate solves are around 6 seconds!

Gamr changer!!

[Jkulin]

Adam, I never ever plate solve on the NCP and all texts books will tell you not to either.

Slew to something in the south at about 60 degrees up, enter the co-ordinates in SGP or select the co-ordinates in APT and let it blind solve, might be useful if you clear the stored cache in EQMod so it starts fresh.

HTH.

[tooth_dr]

20 minutes ago, Jkulin said:

Adam, I never ever plate solve on the NCP and all texts books will tell you not to either.

Slew to something in the south at about 60 degrees up, enter the co-ordinates in SGP or select the co-ordinates in APT and let it blind solve, might be useful if you clear the stored cache in EQMod so it starts fresh.

HTH.

Thanks John for this info.  Just to clarify previously it only worked if I plate solved in home position.  It simply didnt solve or did something weird, unless I solved at home position at the start of every session.  I never bothered working for a solution.

This was before I switched to EQMOD last week.  Since using EQMOD I have not plate solved at the NCP, and I'm using CdC now, and the plate solve in APT just works properly!  I have several sync points saved, for the targets I've imaged so far.

[Jkulin]

Great hear Adam.