130 with motor mount

[dtr42]

hi guys .

was on a few weeks ago and decided to keep my binos but have a chance of the skywatcher 130 [f900 d130] with ra drive on an eq2 mount for £100 but what checks should i make to see if it's a good un ??the guy is a mate of a mate and he is happy for me to look it over before purchase .

thanks dave

[Lancashire Astroguy]

I have the shorter focal length (650mm) version of the same scope, which I think cost me £199 in 2007 when I bought it brand new. As far as things to look for, I would suggest a few tests if your friend will allow you the scope for the evening.

(1) How long will it track an object for? Mine will keep an object reasonably centred in the FOV for at least an hour, providing my motor batteries are fresh and I've done my polar alignment accurately.

(2) Look at a field rich in stars, such as the Plieades. Do stars get blurred or pointy towards the edge of the field? This may be an issue with collimation.

(3) Does the red dot finder work - this will be invaluable!

(4) Can you see the shadow of Saturn on its rings?

(5) Does the ring nebula actually look like a ring and not just a blob?

(6) Can you see dust lanes in the galaxy M82?

(7) Can you resolve the trapezium in the Orion Nebula?

(8) Can you make out any surface features on Mars?

(9) Does it come with at least the 2 eyepieces it was supplied with (probably a 10mm and a 25mm)?

If it passes all the above questions, and the telescope visually appears to be in good condition, then £100 would not be a bad price to pay for the scope.

Regards, James

[rowan46]

check for scratches on the mirror, any big dings on the body no missing bolts or stripped threads on the mount, did he use it much. I tend to find that people who use their scope tend to respect them it's the ones that have been stored away and forgotten that often get knocked about. as to collimation a badly collimated scope needn't be a deal breaker but do make sure that the screws on the secondary aren't mashed check the focusser racks in and out smoothly. james has already mentioned the motor and red dot the motor takes I think 4x d cell and the finder uses 1 or 2 cr2032 I can't remember which. I get my mates to take some batteries with them when they look at a scope just in case. as to what you can see that depends so much on seeing and light pollution I have a perfecly well collimated c5 and I can't see dust lanes in m82 from my site in birmingham.bit if you can my guess is it's a good un

[dtr42]

thanks guys ,

the guy seems quite happy to show me it in use [he stays outskirts of glasgow so has less light prob than me] he's going to set it up on the next clear night and let me have a good look [hopefully in next few days ,thanks for the help

dave

[JimStan]

Jupiter is still up in the evening sky. You should be able to see the cloud bands on the planet, and the 4 moons should be tiny pinpricks of light, with maybe a slight indication of size to the largest one. But my main point is that the focus should be sharp, and the contrast good enough to distinguish the surface markings.

Good advice has been given, and it is great that the seller is willing to show you around the sky a bit. Good luck!

Jim

[dtr42]

bah bumhug.

got to meet mate's mate set up his scope [polaris alignement??] scopes to jupiter and

and

and

nothing blurry blob and a whining from the ra motor as it tracked for 5 mins then stopped[from a "boost pack 12v from halfords] he says collimation of. i say get better from my 10x50 and it degenarated from there so Im back to square 2 [gave up on 1 lol]

[kernowstargazer]

I think some of the good people of SGL should get a Sticky in the beginners section about what to look for in a second hand scope so people dont get ripped off as us newbies havent a clue what to look for to see if the scope is any good or a complete pile of rubbish. Good luck with your scope quest.