Astro Baby'a HEQ5 Polar Alignment guide.

[kirkster501]

http://www.astro-baby.com/HEQ5/HEQ5-2.htm

Hi all, As a result of a recent thread I have decided to try and play with AB's guide for my mount.

I have some questions. Upon final completion of the setup - does my Polaris small circle on the reticule (i.e where Polaris is meant to be on the main Polar scope circle) supposed to match the PF software represenatation? For example, in the PF sofwtare if the small circle is at 9 o'clock should it also look like that in my polar scope? It does not in mine. This could be because I had the Polarscope reticuel out for cleaning.

I am fine with step 7. I don't understand why in step 8 we have to unscrew the tiny screw on the longitude circle... What does this achieve? I did this step and I can still rotate my longitude date circle around. And then we set both cirles back to zero.... Why?

anyway, I do exactly as instructed but the view I have does not match the PF software....

I appear to be missing something.....? Appreciate a steer please...!

Warm rgds, Steve

[Jiggy 67]

Try looking at these documents, they may help

How to use a polarscope.pdf

Polar Alignment .pdf

[kirkster501]

Thanks. Been playing for two hours and still my polarscope view does not look like the Polarfinder software shows it. Hmmmm... Maybe I'll come back to it tomorrow with fresh eyes. Can;t see what am doing wrong at the minute.

Just a quick question. In teh polarfinder software it shows time at teh bottom of each picture (a time that is not the curretn time). I assume that is teh Polaris Transit time? Thast waht i have been usign to set teh circles prior to me movign to the current time.

What does the screw that AB refers to do? Does it "lock" the polarscope in some way?

[kirkster501]

Hi - I Have fathomed it I think.

The mistake I was making is thinking the Day and DATE at the bottom of each PF chart was the TRANSIT TIME !!! So when it says Tueday 18.09.12 I thought that meant Polaris transits on Tuesday at Nine munites and 12 seconds past six in the evening!! Doh....... Of course not thats the date itself !!!!!

So I managed to stumble accorss ths site

http://aa.usno.navy.mil/data/

that gives you the time of a Polaris transit.

I use that data as step one and then rotate RA to the current time and BINGO Polaris circle is in the place it should be in the viewfinder.

Does polarfinder use GMT or DST on teh times it dispalys sicen i thinkI am slightly out? Also is there any program that tells you when Polaris last transited in case I forget to run the stats through the website to get teh transit time?

If I can find the algorithsm I coudl knock somethign up in Visual Studio simple enough

MAny thanks, Steve

[Astrosurf]

Hi Steve. I have to recalibrate my mount which will remind me of the steps enough to let you know what I did. But I'm sure someone will be along soon!

The reason why you unscrew the tiny screw on the longitude ring is to align the little line on the ring (the date/longitude index mark) with the zero on the date circle when you've got the scales set for a Polaris transit. So if the date circle dial moves if nudged at any time (I find this when packing the scope and unpacking), as it's not fixed, you just turn the date scale until the zero is aligned to the index mark again before you star polar aligning. It's just a reference point. You only need to do the calibration step with loosening the ring once. I do it every so many months. It's usually still accurate.

[Astrosurf]

Are you using this software? http://myastroimages.com/Polar_FinderScope_by_Jason_Dale/

Set your location co-ords. I set the view to reversed view as your polarscope will invert the image so top is bottom. I click forward one hour, or back one hour until the dot for Polaris is at the six o'clock position. It doesn't have to be very near your current time. Any transit will do. I assume it can be weeks away but I assume as close to your time as possible is best.

Take the date and time to set your scales.

For polar alignment, ensure your altitude scale is set to your latitude. I ensure the zeros on the scales are at their respective marks (this is where the index mark on the ring comes in. The RA scale is always locked down but be sure the scale hasn't shifted). I then turn my mount in RA until the date and time on the setting scales line up (the mount is rotated over possibly quite a bit now.) Lock the RA clutch then position Polaris in the little circle using the alt and azimuth bolts on the mount. I have to gently move the whole mount to start with, so you'll find it's best done without the scope and counterweights. But your scope is small and light I think, so you might be able to do it with it attached. Take care not to topple it over!

If I've made an error due to very dodgy memory I'll let you know soon!

[kirkster501]

Hi there, thanks for your kind thoughts. Yes thats the software i use. But it doesn't give the transit time - only what Polaris will look like at that time in the Polarscope. So to paraphraae you, your idea is to step hour by hour until Polaris is at the 6 o'clock on the PF software and that will indicate the transit time???? I will have a ook into that idea if so - sounds liek it woudl work.

One issue with this whole alignement business. The scales are not that acurate are they on the HEQ5? Its OK if the time falls on whole hours and on 10's in the month circle. But between those its a question of gettign the best you can by eye-ballign it.....

Steve

[Dipper]

If you use HEQ5 then I believe it has in-built Polaris transit time option. Try Utility function - Show information - Polaris pos.

[Astrosurf]

Thanks. Been playing for two hours and still my polarscope view does not look like the Polarfinder software shows it. Hmmmm... Maybe I'll come back to it tomorrow with fresh eyes. Can;t see what am doing wrong at the minute.

Just a quick question. In teh polarfinder software it shows time at teh bottom of each picture (a time that is not the curretn time). I assume that is teh Polaris Transit time? Thast waht i have been usign to set teh circles prior to me movign to the current time.

What does the screw that AB refers to do? Does it "lock" the polarscope in some way?

Hey Dipper, I forgot about that, thanks. I've never used it so can't comment!

As I know it, the time and date that are displayed on Polarfinder when the star is positioned at it's transit position, is the time of the transit. See attached pic (Polaris is in the 12 o'clock position here).

You could also just roughly polar align ensuring the constellations of the Plough and Cassiopeia are lined up with their respective diagrams in the polarscope. The diagrams won't overlie the actual constellations as they’re too close together. You just keep looking at the sky and then through the polarscope until they're in roughly the some position. I use Astrobaby's method as I think it's more accurate.

[kirkster501]

Hi again. Cool. Thanks. Isn't transit time the time when it is at 6 O'clock though?

Also, is the time on PF software GMT or the "actual" time? I think it is the latter because the first chart always seems to refelct the current time from the Windows clock....

Rgds, Steve

[kirkster501]

Guys thanks to all who helped me with this. I have got it clear in my head now.

Steve

[kirkster501]

If you use HEQ5 then I believe it has in-built Polaris transit time option. Try Utility function - Show information - Polaris pos.

Thanks Dipper but i dont use the handset - i'm a EQmod man myself... ;-)