Carbon Brush

Presumably the cameras bought from the Dwarflab site incur import duty and VAT? Anyone been down this route? Looking today the site is offering the deluxe at £424 incl shipping. 365 are asking £539 incl shipping. In other words very similar prices if there is VAT and duty to pay - then of course there may be carrier/importer fees. My interest is more daylight for moving wildlife - have already spent on astro mounts and cameras.

Rather than wasting clear nights - or having to wait for a clear night - why not use an artificial star? These do need to be placed a long way from the scope. Some are usable in daylight. I took a glance at FLO offerings and you can spend £19 or £117. Probably worth looking on SGL for others experiences and comments on these.

Anything you see and enjoy - especially something new - is worth a mention.

I think Peter has a valid point. The vertical artefacts differ significantly between intra and extra focal images. Skywatcher have a habit of fitting shiny drawtubes to their (dark grey painted) tubes. If this is happening, then black paint on the drawtube and/or tube flocking will help. An interesting trial would be to put a bit of black card on the drawtube - held by an elastic band.

Hi Steve. Yes easy enough. There are screws in the black paint just forward of the white ring. Shown in pic 8106. This is a 200P and there are 6 screws. Indicated by the screwdriver. Moving to pic 8107. This is a 250P. Same principles, just a bit more support for the mirror in the centre of the cell. If you look in the for sale section, I have listed a 300PDS tube. Again 6 screws. Slightly different again mirror cell centre. But the same principles. Usually the screws are M4. I usually put a tiny bit of silicone (clear) grease on the screws on reassembly. Work on the assumption (as I do) that the grease is made from a platinum/gold alloy and you are a miser😁. The grease won't melt and run out on a sunny day. It prevents binding from corrosion in years to come. You are of course leaving the scope out on dewy nights🤔. HTH, David.

Another easy enough test is to remove the mirror cell completely and check for mirror fit/clearance. Just a few screws to remove from the periphery of the tube. If you mark the tube and cell (masking tape) so you reassemble in the same orietation, it will minimise collimation effort. You should have sub millimetre lateral clearance to the mirror at room temperature. The clip screws should loosen the clips with a fraction of a turn. If not you are pinching the mirror. If in doubt, re-assemble with the mirror definitely loose. You may get an off collimation star test result - but no spiky bits this time will indicate you had mirror pinch. HTH, David.

I'm surprised no mention has been made of the temperature when checking, and the materials used in the mirror cell. Assuming a mirror glass has zero expansion with temperature. It is only the metal cell we need think about. Thinking about a 300mm diameter mirror, maybe 30mm thick. If the cell is made from (expanding with heat) metal, it needs to have a gap around periphery at room temperature, so it closes to near enough zero when cold. If the gap isn't there, the mirror is pinched when cold. Taking an aluminium cell, it needs to be about 300.14mm to hold a 300mm mirror at 20C, then grip with zero clearance at freezing point. In other words something like 0.14mm around the periphery indoors will be good for a cold UK night. That is 0.07mm on each clip, regardless of the number of clips. This sort of number is business card, recycled xmas card, rather than credit card. Obviously a smaller mirror can have lower clearance. Or if you set up the spacers when the scope is already cold, you can use a smaller clearance. Cast iron has about 1/2 the expansion of aluminium so requires less clearance. I haven't looked up aluminium alloys, or steel. But I don't see the numbers being hugely different. If you have thin cork, or similar squashy material holding the mirror edges, if you lose the thermal clearance, then initially the cork/sponge squashes in preferences to the glass deforming. As for the screws holding the mirror front to back. Being only around 30mm long, the numbers above can all be divided by 10. The pads are to prevent mirror scratching. In other words a mirror has bit of side to side movement when checked indoors, but almost no front/back play. Just my uneducated and ill iformed thoughts🤔 David.

I got into spending on a decent scope about 20 years ago. At that time motorised mounts had a big price penalty compared to manual. As for goto - if you need to ask the price and all that. Strangely I don't remember dob mounts being popular among the big manufacturers. Or is it my defective grey cells? I did own an ETX90 that on paper appeared to do everything, But experience with this, and other goto mounts led me to the opinion that goto was a faff. Having to set the date/time and align every time out. Some earlier Meade handsets used to corrupt memory if they got a dodgy 12V connection. Requiring throw away, or an expensive programming adapter. Today we see a lot of starter type scopes where the electronics cost means compromising on the mount and and optics. But when your mount has gps or talks to your phone, a lot of goto setup faff has been addressed. To the future. There is a huge amount of amateur equipment in the world. A lot with good optics. Will more people look at putting an old optically good scope on a new clever mount? Will the clever image processing get used more to correct for mount errors on a visual scope. We already see guiding used when imaging. Why not use guiding when visually observing? I have no doubt the visual enhancement aspect will move forward. A scope that knows what object you are looking at and puts the effort into enhancing only the parts of the spectrum relevant to you. We already fit filters on eyepieces for visual. This could done for an EV scope with it's own filter wheel. As we age, our ability to extract detail from dim objects diminishes. Electronic eyepeices of any sort can help here. No need to worry about dark adapting for faint fuzzies after viewing the moon. Sadly I think that increasing light pollution is going to restrict our UK experiences. I don't know if it is the rose tinted glasses with fond memories of the past. But I don't think we get the clear nights that we used to see. Climate change? I have not researched this, it is just an uneducated and biassed opinion.

A power tank/bank (whatever brand) that has a 12V lead acid battery will not damage the mount. Just ensure the lead to the mount is fused in case of shorts. A power tank/bank of unknown internal construction, except it contnis lithium cells carries risk. It can impose voltages outside of mount normal operation. Note the RVO offering is 12V 17AH = 204Wh. The amazon device claims only 99Wh. Unless you really need other than 12V, an easy decision really. HTH, David.

Looking forward to your reports. I have the older daylight only model.

Hi and welcome to SGL. Before jumping to the BUY IT button, a few words. Whatever you buy, get it from a speciailist astronomy retailer. He can provide after sales support. The specialist (in general) won't sell you the wrong scope - provided you talk to him. Check out the site sponsor, FLO (top of page) they have a beginners scope guide. Do not buy from the likes of Amazon, Ebay, Currys, department store, local selling sites, etc. If you don't know what you are looking for, you can easily buy a lemon or something only fit for landfill. Even if you buy a branded scope new from the likes of amazon, they can't help to resolve problems - only offer a return/refund in a short time. HTH, David.

They might be empty boxes. Just had an idea about the next astro items I sell😁 Sorry just looked at his listing on ebay - there do appear to be box contents.

Based on my experience of ebay inaction after reporting scams, I would not be surprised if they wait for someone to lose money, or them get 100 'dodgy' reports. Thank you Paul for posting.

To add.... USB2 is slower data than USB3. That makes it more tolerant of cable losses. If you are sending relatively few commands, like controlling a mount and sending a few camera commands, a slow data rate is fine. If you want to live stream high resolution video, you need a high data rate. Cheap cables often give problems when pushed to the limit. A 'known name' screened cable is essential. The cheap stuff is best regarded as OK for low power charging, or a short length. In the grand schemme of astrophotography spend, and few clear nights, why chance it? If you have spent >£1000 on a scope, mount and camera, why fuss about even £100 on decent cables? HTH, David.

Sorry to hear the mount has failed. I think the long service life shows the build quality. Should you decide it is scrap, then please let me know. I have one in (differently) non running order so am interested in making a package.

Ah but is there a grain of truth behind our tales of woe? Is there more cloud, or more water in the air, or more thermal instability (on long term average) now we are experiencing climate change? Or is it that when we bought our first scopes we would go out as long as there was a little point of light somewhere for a few minutes? Now we look up and don't bother unless it is something special?

There are a few objects that don't come around time after time, or are time limited. Comets are the obvious example. Halley is a predictable once in a lifetime. Others I have seen were on the first pass since telescope invention. Near earth asteroids we can ignore. If they get big or bright enough for amateur viewing, maybe it is time to take cover🤣 Anyone wanting a photo of the ISS with a shuttle alongside. Sorry, that photo opportunity has gone. But other craft do visit. I consider myself fortunate to have viewed both Venus and Mercury transits. Then the 1 in 400 years (I think) Saturn/Jupiter conjuction. There is always something to see. It is just a case of knowing what is around at this time of year, or how the planets are placed. Then of course if you are able to travel overseas to a different latitude, the sky is so different. I was completely lost on a holiday near the equator. Polaris was useless as a pointer, being almost on the horizon. But all those (unseen by me) southern constellations. Wow. I like to think about viewing plans based on what is going to be around, rather than having specific targets.

Last night I wanted to try my 'Talwatcher' hybrid scope with binoviewers. I had established the ability to focus without resort to barlow in daylight. But wanted to try night use. Rain showers all day and expected to continue in the evening. But some stars were visible. Venus was shining brightly in the west, nicely placed to view from in the conservatory, with the door open - I was ready for the rain. The seeing was awful, changing by the second. I could sometimes make out the phase. But the binoviewing worked. Advice to self and others. Don't try to view a low target when the sky is known to be unstable.😁

Well the company exists, as does the CEO. However, web page aspirations and projects that fly are often very different.

Solar panels from the like of Amazon are very much over sold on their abilities. In practice your home panel is fixed so it only faces the sun head on, once each day. At all other daylight time, it has lower output. Then there are clouds. Then they degrade with time - a few years. Then there is risk of seals failing and letting in rain on cheap panels. Whatever panels you buy, talk to a specialist company. They will offer you choices and know to avoid product that causes problems after sale. A bit like the advice about buying astro kit from amazon and the like, or an astro retailer.

In times before affordable lasers, I always used a cap/cheshire. These being upgrades on a 35mm film canister with a hole poked in the centre. These days I really like a laser on almost any scope. The dot movement is very useful when racking a focusser in/out to porve it runs true, or when applying gentle pressure to things. It shows you where things are not right, or wobbly, or loose. Then there is the question of whether your arms can reach everything while looking down the eyepiece tube on a big scope. All the tools have their place. Somewhere I even have a book (albeit a thin book) about collimating newts. Not just the single page, or even couple of paragraphs description we normally think about! As long as you get decent views, don't worry.

Come on sign up!!! https://petition.parliament.uk/petitions/632558 You may not agree with the exact wording, but this is an opportunity to get the ball rolling on a national level, instead of every individual having to argue their case. There are THOUSANDS of SGL members, and potentially millions of people insterested in a dark sky for other reasonas. But only 570 signatures at present.

You beat me to it😄. Another big lump passing close by, discovered only recently.

The link is https://petition.parliament.uk/petitions/632558 May help avoid searching. Signed of course. I am 213 - where is everyone?

Ref the B&Q trolley. Not recommended. We use this type at work. They all come from China with different badges. The handle folds down onto the base. so modification needed to free a dob. There two fixed, and two swivel castors. Not good for a restricted space. The narrow wheels and solid tyres are fine on smooth hard surfaces only. The base is made two steel sheets pressed together. It would be difficult to add jacking/levelling screws etc. without adding a base plate. Sorry to pour water on the enthusiasm of anyone who may be thinking of buying this product. If you want to carry some boxes. Or shift a heavy item they are fine.