kman42

Ahhh thanks, forgot about field rotation. Lucky I held back from the impulse buy!

I've seen a Celestron FI 130 come up locally for pretty cheap. Had a close look at it, and since it has a dovetail mount I can remove the scope and put my DSLR rack on it. The aluminium legs are very slightly wobbly, but I'm pretty sure I can stiffen the tripod with a few extra bracing members. At first glance it looks like a cheap and easy way of getting motorised tracking for my Astrophotography, but my main question is how good is the tracking on the mount? Is it accurate enough for wide field Astrophotography up to about a 400mm lens?

I have a mount with DEC and RA stepper motors, driven by an AstroEQ box and controlled with PHD2/EQMod. I'm getting a recurring problem where I plug everything in, an it works at first. I'll start EQMod running Sidereal to get some drift alignment going. However after a few minuts the stepper motors make weird noises (eg. the DEC stepper, which should be inactive, starts a constant whine with a rising pitch!?). At this point, the mount becomes completey unresponsive to any EQMod commands. I managed to reset the problem once, but next time I set it up it happened again. Now I can't reset it and can't remember what I did. If I disconnect and reconnect everything, the whines just start back up where they left off. I'm not even sure if its a problem with AstroEQ or EQMod. How do you reset either of these?

So I went to reconfigure ASTROEQ but when I try to read the code in the Config program, it just hangs on "reading eeprom" and the times out after a while. Similar situation when I try to update firmware - it just cant make contact with the ASTROEQ. I've checked different com ports too... Anybody else get this??

Ahah! So, I was missing a step - set the EQMod home position. The puzzle falls into place. Thanks!

I don't have a handset. I'm running with PHD2 and an ASTROEQ box. What mode should I set this to? And what about unpark mode?

I remember trying it and it didn't seem to make a difference, but I'll try this again.

When I set my location correctly (Toowoomba, Australia), EQMod runs the RA axis in reverse (West to east). This happens whether using the slew commands or the tracking function. To get the RA to move correctly, I need to set my location to North and West (rather than South and East). I've screenshot the EQmod settings below, have I got some setting wrong?? (Port is not available because I just opened EQMod to capture the settings).

OK, so I can see now how PHD2 would be able to get RELATIVE position from EQMod. But if I walk through the steps on a night of astro: 1. I set up the tripod with a rough polar alignment 2. I load PHD2/EQMod, which has my Lat and Long saved 2. I point roughly towards the meridian & equator, and do a calibration 3. I open the Drift alignment tool, and it tells me I am currently pointing XX RA and XX DEC. How did it work this out? At no point have I given any kind of information to PHD2 or EQMod about where I am pointed. I feel like I'm missing some crucial part of the set up, which I hope will be revealed by digging into the above question

OK, so that just leaves my question of HOW does PHD2 come up with the values it reports in the Drift alignment tool for your current RA and DEC? Where is it getting that information?

Sorry, yes we're interchanging a few terms here. My confusion summarised: How does PHD2 have any idea where the telescope is a) pointing, and b) physically located? It reports current RA and DEC position in the drift alignment tool. How does it come up with these numbers? And surely these positions are dependant on both where you are pointed and where you are located on the earth? Or am I mistaken on this? Also, you mention that Lat and Long need to be entered into EQMod - I have done this, however this made EQmod run sidereal tracking in reverse. I had to change my location from South to North to get the correct rotation.

Thanks Terry, I was misunderstanding the role of calibration - am I correct in saying that it calibrates for the equipment, not location? But how does it get this information? Is it extrapolated from the calibration process? Otherwise there must be a GPS or something telling it where it is...

So it sounds like the calibration process tells PHD2 where the mount is? And once I've calibrated, I shouldn't move manually using the clutches. How would I troubleshoot / fix the mount correctly reporting its position?

Ok, so had a go tonight and it turns out a) that I do indeed need to be running the EQMod tracking while in PHD2, and b) the EQMod was tracking in the wrong direction. I can now get sensible results from calibration and the Guiding Assistant. Next questions are about drift alignment. I'm seeing "current scope pointing" numbers that don't make a lot of sense to me. When I go to adjust the Altitude, it wants me to slew to 0 DEC, and thinks I am at 90 DEC, but I am pointing at the Equator?? aside from that, 1. How does PHD2 'know' where I'm pointing? 2. Can I manually move my mount to where it is asking? As in, unlock the RA and DEC gears and rotate the mount head where I need it to. Or will that stuff it up?

This was always my understanding - 58mm is the physical size of the magnification. After some more research I have come to realise that I think I need to engage sidereal tracking on EQMod, after which I should go through the guiding steps on PHD2. Seems like a basic thing to miss, but believe it or not this is not mentioned in any tutorials! I'll give this a try when I next get a chance.