Carbon Brush

The photo from @AstroNebulee clearly shows an Intertek PSU, with model number. A brief search of the Intertek web site did not produce a hit. Maybe it is obsolete? However, you must keep the documents available for time after last shipping. Forget now if it is 7 or 10 years. Maybe you need to contact them directly to get the test certificates? I have seen this company name around on internal (PC type) and desk top power supplies. But I have not included their products in anything I have designed/built/specified. The amazon listing images show two different power supplies. One Intertek, the other unbranded. So what arrives if you buy? Absence of the maker/importer details on a product (which is large enough to mark) is a compliance fail. The amazon offering looks to me like the usual case of 'it looks the same'. I have seen this on everything from hobby lathes to dubious semiconductors! HTH, David.

I would apply the same precautions to this device as many other devices of little known provenance. In this case risk of wrecking a camera that is 10x or the value of the power supply is added to the usual performance and shock risks. The amazon description is, like that of many of their offerings, a fairy story. Is that rosh or rohs approval🤔There is a lot more! By all means buy one. It is after all a free return if it is obviously not right. Once you have the kit in front of you, the manufacturer is identifiable. Check out the (claimed) approvals on the manufacturer web site. The test reports allowing production of compliance certificates may be downloadable. You may have to ask for them. Basically to meet the approvals they claim, the test certificates must be immediately available. It is far from unknown (even in the UK) for end user sellers to say to a manufacturer 'just put a CE label on it for us, you don't need to test'. That has been said to my work more than once. The response is always (insert as approriate) off. I once asked about approvals for a mains powered product I had purchased from amazon. Basically the mains cable was too thin for the fuse and the fuse rating was far too high for the equipment power. The manufacturer sent me a 'test certificate'. Actually the certificate was a page listing cable/fuse sizes (extracted from an EU standard) confirming my assertion on incorrect cable/fuse! Another mains powered product had a fake mains fuse. Another had a piece of printed circuit track as a mains fuse! This product may well be pefectly good. But history is not on the side of 'never heard that name before' products sold by amazon. I would look for the approvals proof before even thinking of powering an expensive camera. Do let us know how you get on. HTH, David.

Assuming you have a handful of small drill bits... Drill holes in a piece of scrap metal or plastic. Drill a 4mm hole and a 4mm screw should just go through. Works for all sizes of metric screws. If you start asking about imperial screws things are different. Looking at your photo it looks like you have M4 & M5 screws. HTH, David.

Thank you for posting. An amazing sight. I think if I had that view it would be specs cleaning time. Or if imaging, looking for lens problems😄

These comments are valid for a lot of mounts. There are a lot of threads on SGL talking about mount power connector problems. We have to remember that these DC connectors are the definition of cheap and cheerful. The contacts are not precious metal plated. Contact pressure is not well controlled at manufacture. After a few years what bit of bright plating they did have has worn away - or corroded. The spring contact pressure may well have relaxed. Then the very flexible power cable may have broken strands inside the (by now hardened) PVC sleeve. A new (quality not cheapest) power lead is plug and play, and a few quid. If you have the soldering skills, replacing the PCB connector by new will give a good solution. If you are going to the bother of dismantling the mount to replace the power connector, consider an alternative connector type. Something with proper strain relief and good contact materials. Just add (thin) wires to the PCB running to your new connector somewhere on the mount housing. No need to desolder the old connector. HTH, David.

Another 'good choice' comment. Don't spend on accessories yet. OK maybe a low cost collimation tool in case the scope is 'off' when it arroves. Note low cost. Don't bother about eyepieces, filters and more until you have looked and found limitation with the kit you use. It is very easy to buy loads of accessories that you rarely use. Enjoy the journey. David.

With ABS look at the post history. What kit has the seller sold in past year for example. If it is a scope a week, he is an unregistered dealer. If it was a different scope 6 months ago, he can tell you about that. Talk to the seller by phone - not just email. Don't forget there is a lot of overlap of ABS & SGL members. You can look up the seller SGL name and find his post history on here. A good contributor? That is a positive sign. You can also message him on here as a 2nd check on identity. For example, I have an ABS username but can't remember last time I was on there actively. Anything could have happened.

When looking at focus issues in general I try to do it in daylight, looking at a horizon or distant object. Far easier than fumbling in the dark, or squinting at a bright sun. Gradually back away from the scope, holding the eyepiece on axis, as if using a long extension tube. That gives you a good indication of what length extension tubes may be required. If you have the opposite problem, depending on the eyepeice, you can sometimes remove the bottom part. That sometimes gets a few more millimetres into the eyepiece holder. With any scope, using the above with and without a diagonal may help establish what is going on. Scopes that come with a diagonal often focus well away from the tube when the diagonal is omitted. HTH, David.

Running the dew straps at a low PWM setting won't harm them. However, the high pulse current may cane the power supply if they turn on together. Now if you told us the resistance of the straps and the PSU capability..... An easier fix? Why not wire the two USB dew straps in series and connect to a 12V supply?

A point not yet raised is cell (battery) construction. Think about NiCd or NiMH packs in power tools - yes 10 years back. They are lithium now. When constructing these cells, the maker has to juggle the capacity (amps x hours) against their ability to retain charge when left. The internal construction is a roll of metal foil with blotting paper on top soaked in clever chemical, then another metal foil. Fasten a wire onto each metal foil. Roll it up tight put it into the can. You have a cell. OK there is more to the chemistry and construction but the simple explanation works for me. If the blotting paper is thin, you get a cell that will deliver a high current for your electric drill - it has low internal resistance. It has high capacity (amps x hours) for a given volume so you can drill lots of holes between charges. Great so far. Unfortunately this construction leaks charge away quickly. After a year or two of use, you find the battery goes flat in a few days of storage. If you had cells with thicker blotting paper, the drill wouldn't perform as well. But it would be charged when removed from the tool cupboard. Another useless snippet of information.😁

A thought on the door - if it is not too late. Just how big does the door need to be? Shed doors let you get wheelbarrows and big mowers through. For convenience they often go full height. For an observatory you don't need it very wide and it doesn't matter about ducking your head. Doing this can leave more strength in the wall. On my build, I did wonder what size I might have to get through the door. Then I realised that even if I bought a 30" reflector, it could be hoisted in with the roof off😆

Echoing comments from @Stuart1971 Basically if you have to be told how to do basic soldering work. If you don't understand how volts & amps work.....What are you doing opening the box? I started following this thread (and contributing) hoping to help. This is my last post in this (extremely frustrating) thread.

Another vote for aircraft contrails.

It would be a big help to provide a link to the particular battery you are using. A quick glance at the Eco Flow web site for the Uk did not show a 240WH product. However, as 240WH is of course 12V/20AH. Igt is certainly not excessive for a mount & computer & camera(s).

Perhaps an element of fixing the lock on the stable door after the horse has gone. But perhaps something of use to others contemplating modifications to equipment. First of all I agree with the idea that the DC plugs used on the popular mounts are awful and unreliable. However, a cable tie fastened to the body to take the strain relief is very easy to arrange and fixes 99% of issues. In addition it still allows checks on different power supplies, etc. when fault finding. Second. As a general rule, printed circuit boards are expensive and easy to wreck. Components are often cheap. If you do insist on removing a component like a connector, or a chip with lots of pins, think about preserving the board before you start. For example take a modelling grinder (Dremel) to the connector so only the pins remain. Or you can nibble it using fine side cutters. Then remove the pins from the board one by one. Heat with the soldering iron and GENTLY pull using fine pliers/tweezers when the solder melts. For a chip, you can cut the legs using your fine side cutters and body falls off. Then you remove the legs one by one with minimal PCB heating. Third. Think about your choice of solder. Nowadays boards are built using lead free solder. In an earlier century, it was a tin/lead alloy. Try to get hold of the traditional electrical solder for your repairs. The old solder melts at a lower temperature and often tins wires and flows more readily than the new stuff. Especially in the hands of a less than frequent board repair person, it is more likely to give a good outcome. Finally, after soldering, clean off the flux residue. There may not be much - it all depends on the solder you use. However, the more active/aggresive fluxes can mean corrosion a few years (or sooner) after exposure to the air. Hoping this is useful. David.

Depending on where in the garden, you might consider a scope cover disguised as a garden feature. I have seen photos of a fibreglass pretend dovecote. In reality a weatherproof cover for a mount. The scope went indoors. I have seen a tardis. Open the doors and slide back on rails to reveal a complete imaging setup. When considering my observatory, I was told that a bottle recycling bank in a prominent location would not go down well. Hence the decision to go for a shed with roof rolling over a pergola.

Thanks @Louis D for bringing up astigmatism. In simple terms, if you don't need astig correction, forget the specs and rack the focus in/out to compensate.

In the ratio of launch cost/revenue/fine. It is a bit like us getting a 2p fine for littering. Perhaps it sets a precedent? Next year the fines will be larger.

The obvious questions that have not been asked.... Does the mount/handset work? By that I mean you press buttons to accept time/date/location and it should then be able to be slewed. If so, it is a display problem. Does the display pattern change if you push the buttons you normally push after a power up? A changing pattern suggests a ribbon cable connection issue as described above. However. Some old Meade handsets could get their memory corrupted following a dodgy power connection - like a loose power plug. This requires specialist programming kit for recovery and unless you know someone who has the kit, the handset is best considered scrap. Good luck and keep the information coming in.

If you look at someone like Interparcel you will be able to get quotes from multiple carriers. Often at lower cost than contacting the carriers directly. You can download labels as PDF to send to your seller so there are no addressing errors. As for insurance. You are best regarding it as non existent. There are various SGL threads covering carrier avoid payment techniques. Just select a carrier who you think is going to be trustworthy. As a general rule, I use UPS for work. Though other big names offer good service. A lot of carriers (DPD, Hermes/Evri for example) use a lot of agency drivers at the delivery end. They may not take the same care as a full time employee.

Good advice from the above. This thread also contains some useful comments.

Certain scopes (and related items) are not handled by the retailer. Items are often drop shipped from a central warehouse. I believe a significant number of Skywatcher products come direct from the OVL warehouse. Then of course if you buy from the 'long river company'.....Well there are threads on SGL about that.

The same pier construction & vibration isolation that I did in 2007😁. Thats 2 of us at least in the UK😆. It looks like well a planned and constructed observatory. Following with interest.

I would add a low cost collimation tool. Maybe you won't make much use of it. Alternatively is there a nearby person who could show you collimation? Once learned it is quite easy and not often required. Then use the scope and see how you get on. Stick with low magnification (longer FL eyepiece) until you gain confidence. Sometimes the supplied short FL eyepeices are not that good. Finder scopes are a personal choice. Straight, 90deg, RACI, red dot. See how you get on. Dew shields can be cut up gym mats. A hair dryer will get rid of dew until you get a feel for the issues. A cheap garden furniture cover will keep the dust off when stored in the house/shed/garage. You may get the impression I am a bit of a miser😁 After a bit of use you will have a much better idea of a wish list. HTH, David.

As someone who has owned 8", 10" and 12" reflectors, may I suggest an 8" for a first scope? It is much easier to handle and will provide mind blowing views. In the UK, you are going to be more limited by sky clarity and light pollution than light gathering ability. Keep asking the questions😃