Carbon Brush

Great news the muck is shifting. I would be wary of using neat IPA. I (and others) have known it damage the coatings on spectacle lenses. Yes plastic lenses so different, but better safe than sorry. An IPA/water mix is less risky. A big thumbs up from me for Baader wonder fluid. I had a really filthy mirror. After some time in the washing bowl I finished it with Baader fluid and no streaks. Good luck with the clean. David.

Yes John. A decline in night vision generally with age is well known and documented. I should have got more into visual astronomy years ago - sigh.

Our eyes cannot see colours at low light level. On a rural road without street lighting (there are a few left) there are no colours, but turn on a car headlamp and the colours show. A simple test is to look at the plain boring colours in a dark garden, then take a photo with the camera shutter open for a few seconds. The grass is once again green. Or fix your camera, with a wide lens, to a tripod pointing to the sky. Leave the shutter open for 30 seconds and you get see some different colour stars. Hope this helps, David.

If you are worried about the hole size & shape there is possibility of shaving the sides using a spade,while standing in the hole. Overdo it and you have bell mine. But you do get a bigger lump of concrete deep down. Definitely hire a cement mixer. An all day job becomes a one hour job. It is also much easier to produce a consistent mix.

Great phrase ' he may have been chemically confused '. I think I would have been there with a kitchen knife to confront him. My crowbar and hammer are stored in the garage so would not have been to hand😅.

Around 10 years ago I remember checking for mag 6 (I think) or brighter orbiting objects in my bit of the sky for a 3 hour slot. There were more than 200 objects listed. I very much doubt the sky is any clearer now. Off topic. If you are wondering on the checking..... I had invited some friends to view the Perseids. There was an after sunset ISS pass but I wondered if there was something else moving in case the Perseids were slow to get going. David.

Good advice from Rob. Much of my kit was bought secondhand, or even multiple owned. If you want to ugrade again later, or don't like the mount, then you won't lose much on resale. If you sell on a new mount think in terms of 2/3 price if it is in really good condition, otherwise 1/2 price. Then of course if Messrs Celeswatcheade have brought out something better in the meantime, do people want to pay much for your 'last years model'? As a general rule I apply the following: Get the biggest most solid mount your wallet will allow. Don't forget your back if you have a long way between storage and setup - all mounts look the same size on web pages! Hope this is useful. David.

My civil engineering skills and knowledge can be written on the back of a postage stamp. My free advice is therefore worth every penny. When digging the foundation, I found conflicting advice. In the end I decided to err on the side of caution. If it is too big, it is just a bit more spade work for a day, and another barrowload of cement. If it is too small then I have to dig again, break out the hardened concrete, maybe dismantle and move the observatory shed...... In the end I dug about a 1 metre cube out of the ground. My pier took more thinking about as it was concrete, an extension of the foundation. So I had to get the height nearly right. In your case just start by using the full height of pier. If it causes problems, unbolt it and cut it to length. It is just a bit of grinding and welding to 'adjust' it. Hope this helps, David.

Totally agree with Cosmic Geoff. The RJ11 & RJ45 (handset/guide connectors) tend to have good life. The flimsy DC power connectors are always the achilles heel. I don't know why the manufacturers continue to put them on scopes. Besides the connectors failing, they sometimes put strain on the soldered joints on the circuit board, causing failure here. My recommendation is for the power connector to be left plugged into the scope. Add a cable retainer of some sort to keep tension off the wire. This can be anything from sticky tape or elastic band, through to a cable tie base drilled into the nearby body. All your power disconnect is then done at the power supply end. I have lost count of how many astro and other items where I have opened the box to solder wires and fit a different reliable connector. Hope this helps, David.

Hello Dogwatch. Welcome to SGL. The best astro forum - well I think so anyway. Excellent advice from all of the above posts. I would only add that if you tell us exactly what scope & eypieices you have, then we can do the sums quickly on image size/magnification and give you better pointers. David.

Ref Cloudsweeper: Yeah Stu - could be better - while Mrs. Sweeper is watching soaps, I keep going to the window hoping for something worth going out for. Restless astro-optimist or what!? Given the standard of many of the TV offerings, even a plain grey sky can be more interesting. David.

An interesting purchase option/price reduction. I'm sure lots of us already have a collection of quality tripods.

Yes that is a 'fail safe' solution. I can confirm its effectiveness from my experience!

I have successfully used an ultrasonic cleaner, intened for jewellery and other small items to free stubborn parts. In this case you would either hold the tube in the tank, or arrange to suspend it. As the cleaning fluid is water, and may alcohol or soap, if you choose to add this, there is little risk to the item. I'm not saying it would unscrew itself (Dr Who sonic screwdriver style). But it does sometimes make things less tight. It might allow you to tell the difference between decorative grooves and joints by getting rid of grime. Good luck, David.

I won't get into the prism type and maker A vs maker B discussion. Or the resultant exit pupil discussion. But as someone with long term chronic aperture fever in the scope dept, I would look at 50mm objectives. Generally 50mm binos are not too heavy or bulky and give brighter views - or let you see dimmer objects. David.

Another ditto. 12 years since planning and 11 years of inhabiting. Just in case you move house, or get few up of staring at the sky........ An ROR design lends itself to use as a general garden shed. A dome observatory looks like a bottle bank - not something for the garden! I got told that when thinking the ROR/dome choice! David.

Perhaps Wales is nearer to Jupiter than England? That would explain why I need a telescope to see the stripes! Unless of course Jupiter is now very close to the earth. A bit like the newspapers talking about Mars getting really near every few years and being full moon size. I always seem to miss that! Perhaps it is the turn of Jupiter this year? David

I use Baader wonder fluid (available from all good astro retailers.....) and the associated cloth. Not cheap. But a bottle goes a long way and costs a lot less than a new eyepiece. Shifts most stains and evaporates reasonably quickly to remove smears. The spray on the bottle ensures even coating with economy.

I think it would be a good idea for your friend to join the forum and ask questions himself. The SW200 dob is a good scope and I fully agree with the earlier posts. But if your friend has to carry it down 3 flights of stairs from a tiny flat and he tips the scales at 40Kg, it is not a good choice. He would not be the first one to say 'oh dear' when he realises just how big it is in front of him, rather than on a screen and has to think about storage and handling. When your friend has a read through some of the many 'first/beginner scope choices' threads on SGL, he will be able to make an informed decision. David.

Well we haven't fixed James' power supply. But we have talked a lot about power supplies in general. Excellent comments on construction and reliability from other contributors. As for PAT for reassurance. Be very wary. Often this work is carried out by people who have been trained to push the butons on the test equipment and look at obvious external damage - nicked cables, broken connectors, etc. They do not have any electrical or electronics knowledge, training, experience, qualifications. If you are concerned about safety remember this. A PAT test box will check the insulation at high voltage, and ensure the earth bond (if present) is able to provide continuity in case of fault. It will not tell you about spiders in the box, old components that are at risk of failure, etc. It will not tell you if the design might fail to put 24V on your 12V kit. 24V won't electrocute you so is of no safety concern. Part of my job is to supervise or participate in PAT testing the company's equipment. Basically if the tester doesn't open the 13A plug and remove the cover from the equipment to look inside, they have only done half the job.

Having seen the general construction standards vand condition, I recommend earthing. That is dig a hole in the garden and bury it. New power supplies aren't that expensive.

A recognised problem with aged electrolytic capacitors is that they dry out if they have had a long hot life. You don't see electrolyte weeping out. This happens when you put capacitors in a box with heat generating components like transformers, bridge rectifiers, etc for a long time. David.

Hi Gary. Another caution based on experiences with 'Made In China' products sold on Amazon Marketplace.. No way is this a 60W LINEAR power supply. At this power/volume ratio it has to be switched mode. If the seller gets this wrong, what else in specification and performance can you trust? When it arrives, before plugging in...... Open up the mains plug and check the fuse. Often 13A fuses are fitted by default. Something like this PSU should use a 3A fuse. I have even seen fake fuses in products sold by Amazon. If in doubt swap for one from an assured source. Use a voltmeter to measure the voltage it produces without a load connected. It should 12V, or only slightly more. Now connect a car headIamp bulb. These tend to be 55W or 60W so will load the supply to its claimed capability. Measure the voltage driving the bulb. It should be similar to the 'no load' value, only slightly lower. Leave the supply running the headlamp bulb for an hour and check for overheating. If in doubt buy from the likes of FLO. They know how you will be using a power supply, so should not sell you something unsuitable or unsafe. Just my two pennorth based on experience. David.

At risk of diverting away from the OP question. Ref Zakalwe. Correct - The Lunt & PST issues are not fungus. But the failures were (to the best of my knowledge) never explained by the manufacturers. The approach was simply to provide a replacement that should be OK. Reports from numerous users do not identify cleaning fluid, damp storage, etc as being to blame. The most obvious usage difference between astro and solar scopes is the amount of light they receive. It is far more than 'day use' optics like spotting scopes. Degradation of various plastics and rubbers from UV is well known. As is paint fade and the like. The Lunt experience suggests optical filter coating can be damaged. For these reasons I wonder if excessive UV into an astro scope might do harm. Obviously a few minutes of unfocussed sun does no harm to the scope. But a scope left all day? What about taking the scope into the suntan lounge with you to kill fungus? 5 minutes here browns your skin more than most UK days. I await an informed comment. Preferably from a manufacturer of optical equipment. As a precautionary step, I have made a lens cap for my Lunt scope. A simple push on cap instead of the fine pitch screw on cap. If I walk away from the scope, the cap goes on. That way the scope optics are only subjected to the sun only when in use, rather than all day. My preferred use of the scope is to set up in the garden early morning and leave it on a tracking mount all day. When (if?) there is a 5 minutes gap in the clouds, or I get a chance to take a look, it is immediately accessible. David.

This thread may be of interest. Given the recent threads about filter damage on solar scopes, I wonder about the wisdom of intense UV for long periods. In all the solar scope damage, the offending glassware has been replaced, often at no cost by the scope manufacturer. But no definitive cause or explanation provided. David.