Digital Setting Circles

[vlebo]

personally, I feel the quality of finish is great. their bases are second to none and their optics are world renowned. with any dob, there's always room for mods and that's the beauty of them but I'd have no issues recommending OOUK. if you can afford it, I'd recommend optical grade of at least 1/6PV and HILUX coatings and it's 'only £180' more for 1/8 - even better. this makes a big difference and the optics will certainly be better than the UK skies allow!

I am in the same boat as you it seems. I doubt a 400mm OOUK dob will ever come on the market used for a very long time and therefore it's a matter of buying new. I have decided to save for this and have budgeted £2500 which will take me a while. like you I have a good 12" dob in the meantime.

Thanks Moonshane, food for thought. I like the idea of the OO dob as it seems pretty light and easily transportable with the base having such a small footprint and not being made of nasty mdf.

I like the mods they offer but need to look into how much of a difference they will make to my light polluted outer London skies.

Thought of maybe getting a 16 " goto Skywatcher Flextube and keep the base housed outside in a small shed and the ota inside but do not seem to like the Idea of keeping an mdf base permanently outside.

Thanks again

Vlebo

[spaceboy]

Hi all

I am going to get a device Astro-Fix Locator which gives digital setting circles for azimuth and altitude (altaz) for my dobs. the problem of course is that most books give right ascension and declination (radec) corordinates rather than altaz.

Is a PDA /laptop with software the only way that I can get altaz coordinates for objects other than bending my brain with trigonometry?

What do others use please? to get their targets?

Thanks

Shane

Hi Shane

Did you do research on Astro-fix. I looked into getting it but found bad reviews so decided against it.

If you have a smart phone there are downloads on the net fthat can help regards Aiz/Alt see http://stargazerslounge.com/equipment-help/116381-anyone-know-free-pda-software-up-date-alt-aiz.html I am currently usin free trial Astronomist but also have freeware Tachyon and Taiyoukei see Astronomy Software List - Freeware, Shareware, Commercial, alfcen - taiyoukei

[Moonshane]

cheers Nick

I did and found this Astro-Fix Locator :: digital setting circle system which was what I based my main decision on.

That said, I should have dug a little deeper and have now as you say found a few negatives, especially regarding build quality re the Astro-fix.

In the lead now is a Wixey and digital compass. Anyone used the latter for Astro??

[insomnia]

I have a wixey on order (hopefully be with me by Tues) I have also attached a bicycle handlebar phone holder to my dob tube. The plan is to use my Android phone as a digital setting circle and to use the wixey for elevation.

My only concern is metal interference between the OTA and my phone. I tried to use Google sky as a push to but the results were hit and miss, but on the whole I could centre on Jupiter and then move to a known star and it would be in the EP (just) I then moved back to Jupiter and centred it in the EP and found that google sky was way off, in fact the Moon was on the screen when in fact Jupiter was about 30 deg further east. I am convinced that the OTA is distorting the GPS signal.

So if you are thinking of splashing the cash on this poor mans push to system then be aware of metal interference.

Maybe you should look into using the wixey and a printed setting circle mounted onto an ajustable platform.

The least astro electrical/mechanical extras the better really,

[Moonshane]

I think I am lucky as my OTA is aluminium so should be OK?

unfortunately, I don't think the design of my OOUK base is conducive to circular setting circles but I have found a cheapie digital compass (£14 on Ebay) which I hope will work OK with my tubes and if it does then great! not much risk at that price and overall with a Wixey less than half the price of the Astrofix.

[insomnia]

You dont have to fix the printed setting circle to your dob base, it can be attached to the leveling base that you place your whole dob onto

[insomnia]

At least the Wixey is fairly accurate, and with the digital compass it should get you in the roughly correct area, you can then do a small sweep of the area and it shouldnt be to far off location.

[Moonshane]

it seems that magnetic north and true north is three degrees west of true north so presumably I'd need to account for this is using a compass to confirm azimuth angles from a digital compass?? this might explain why some find them inaccurate?

[insomnia]

I would find a known object like Jupiter then find out what the co-ordinates say it should be with something like stellarium and then fine tune the digital compass to match, and then find another easy to see object and see if they match the same co-ordinates

[Moonshane]

cheers

Just waiting for a couple of bits to sell and will then order a PDA, a Wixey and the digi compass. I'll report back with a review when I get a chance to try things out! I can definitely use the Wixey and PDA anyway so no major risk as I say.