h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Hi all,

My star diagonal prism is a little dusty- any advice on cleaning, i.e. if I can use anything I might find in the house to give it a wipe, or if I have to go and get something from a shop?

Also, does anyone know of any good UK- based accessory suppliers (online or whatever), preferably with various stuff for sale- I want to have a look at everything from mounts to books, so if anyone's found a good site, let me know.

Finally (for now), does anyone have any tips for getting the best out of a not-so-great tripod/mount? I'm getting on great with the scope itself, but my mount doesn't have any fine- tuning controls, so pointing it at things takes a while and is a little hit and miss, and there's a bit of vibration when I touch it- any tips on damping?

Thanks again,

TK[1]

Cleaning - probably best not to do it. Is your star diagonal a prism or a front surface mirror? If it's a front surface mirror then don't touch it. It can scratch and lose the silvering very easily.

For suppliers, it depends on where you are in the UK. There are a few out there, most advertise in Astronomy Now (a UK monthly astronomy magazine).

Thanks

TK[1]

I'm with Phil on the cleaning issue. If your star Diagonal is a prism you could try one of two things. Go to a decent camera shop and by an air brush for cleaning camera lenses. There are different sorts from a simple squeeze bulb and brush assembly to cans of compressed air that blow the dust away. (The latter would be relatively safe for mirrored surfaces too but only a blast of air and not brushing which will damage the surface.) For a prism a gentle wipe with a lint free cloth will also work but beware of greasy fingerprints which are much harder to remove. Please do not try and polish any mirrored surfaces especially if you have to dismantle the part to do so. You would need to be able to reassemble things to engineering tolerances to avoid spoiling your viewing experience. I once took two eye pieces apart to clean. They were never the same!

For supplies again Phil has got it in one - what he should have added in a BBC disclaimer stylie was "Other astronomy magazines are available". All of them have lots of ads from big and small suppliers as well as classified sections.

turvy

There are other astronomy magazines available, but Astronomy and Sky & Telescope are both US magazines and so the adverts are for US suppliers. Astronomy Now is a UK publication witha dverts from UK suppliers. If TK had said they were based in the US I probably would have suggested another magazine

On the tripod/mount issue, you get what you pays for and upgrading the tripod/mount could be a very expensive business. The telescope me and MC use (a 150mm reflector) came with an inexpensive equatorial mount and probably should be mounted on something a bit more heavy duty. It does the job but as you have noticed there are wobbles that take time to die down, focussing can shift the scope slightly. It's not nice or good but it's something that we've had to get used to given our choice of equipment we use

Thanks both of you I didn't think it would be a good idea to just dive in on the mirror itself, so I thought I'd ask first.

As for the mount... I don't really have any money, so I can't afford to invest in a new one. I was mainly wondering if anyone out there had attempted any successful botch- jobs that they could give me hints about.

TK[1]

What scope and waht sort of mount is it that you have?

It's a 60mm refractor, and it's a very basic alt/az mount.

TK[1]

Some instability comes from the tripod legs themselves. If they are flexible (wooden or light-weight metal) they will flex a lot. One simple trick to damp this flexing down is to tie a housebrick securely to some tough nylon cord and suspend it from the centre of the tripod. To prevent it swinging tie the brick to each leg as well!

If there is play in the Alt./Az. mount all you can do is tighten thing up as much as possible. you will get used to it and compensate!

turvy

Also don't over extend or even extend at all for the best stability the tripod legs. If there is an accessory tray to fit the tripod bracing arms then fit it also.