Carbon Brush

Hi Wes. Thank you for the compliment on my science knowledge. It is actually quite thin. I just know a few intellectual-sounding words and recount stories! It certainly seems that your 'space junk' sighting was accompied by a genuine sound. The time delay giving an approximate indication of altitude. Though whether it was a falling object, or a noisy aircaft it is impossible for me to comment. There are various possible explanations for the Anfield flaming star. A bright object yes. Could it have been an 'iridium flare'? Nothing to do with the element iridium. That is a sunlight reflection from one of the iridiuim sat phone satellites. There are a lot in orbit. They have a large (3M long I think) shiny slab of aluminium as part of the antenna. The orbits and attitudes are well known, and controlled, which makes prediction easy - if you know how. These are extremely bright reflections and usually last a few seconds to the static observer. In your case if it was an iridium sighting, cloud or water droplets, or pollutants, in the upper air could distort the image and modify the colour to you. https://www.heavens-above.com/IridiumFlares.aspx Another possibility is a high altitude aircraft carrying our fuel dumping. Miltary aircraft don't necessarily dump liquid fuel - they sometimes burn it. I have only seen this at low altitude. Once at an air display (RAF Finninglet, Doncaster) I saw an F111 (a US swing wing jet long obsolete) fuel dump during the display. There was a flame about one and half times the length of the aircraft, a roaring noise and I swear I felt the heat. The display commentator was not expecting this and was clearly flustered as he hastily explained what had happened. For the couple of seconds it was taking place I thought that a crash was inevitable. But being in a crowd of 1000 000 people, where can you run? From memory he said the fuel was being dumped at around 100 000 pounds (weight) per hour, almost a ton a minute! David.

A number of people are starting to use the Tracer lithium battery power packs for powering equipment in the field. These are well made and represent a huge step up from the (Victorian technology) lead acid batteries historically used for astronomy equipment. At about 1/3 the weight for a given capacity, they have to be worth looking into. The Tracer equipment is well designed and built. It is difficult to damage the batteries (unlike lead acid) though there are still a few considerations that the user needs to bear in mind. This should help to avoid problems that (sometimes unfairly) get blamed on the battery. The purpose of this thread is to pass on my experience of using a Tracer battery and charger in a non-astro application. The battery was a LiFePO4 module with 40Ah capacity and a buck-boost 12V charger. At around £600 + VAT it is not a choice that most would make for astronomy. Though the precautions and limitations for use are valid across all of the Tracer product range. The batteries contain a ‘battery management system’ or BMS. This is an electronics package inside the battery and invisible to the user. It provides the following functions: 1/ At a battery temperature of 65C (with +/-5C tolerance) the BMS disconnects power. This prevents charge or discharge when the battery is too hot. 2/ If the battery is short circuited, or subject to a high current overload, the BMS disconnects power. This protects against battery damage and possibly external problems like burning wiring or scope electronics. 3/ If the battery is (all but) fully discharged, the BMS disconnects power. The trip point is about 9V. This prevents battery damage. Though whether yourmount will work down to 9V is a different matter. 4/ When charging, if the charger voltage rises too high, the BMS disconnects to prevent battery damage. This happens at 14.6V. Note using the BMS in this manner is NOT a substitute for a correct charger being used. At first sight, the BMS appears to offer comprehensive protection. It is very good but does not cover all eventualities. Consider next the battery temperature limits. The battery may be discharged (used) from -10C to +60C. Charging is allowed between 0C and +40C. I have not been given a statement from Tracer about what might happen to the battery if it is used outside of the specified temperature limits. The BMS disconnects the battery at +65C only. There is no differentiation between charge and discharge. There is no low temperature shut off. Next is the charger. To the best of my knowledge all the Tracer supplied chargers work over a wide temperature range. They have no way of knowing the battery internal temperature and they do not use any temperature measurement input. The limitations of the BMS and charger mean that you, the user, need to ensure the battery is not charged or discharged outside of the permitted temperature range. This nothing new. Lead acid batteries and chargers allow considerable battery abuse and often contribute to failures. So how does this affect you in practice? On a cold night in the UK you might be using the battery at -10C. Albeit not very often. It is a good idea to start with a warm battery as performance will be a little better and you will have more time before the battery cools. The battery generates no discernible heat in use which means it can be placed in a thermally insulating case. If using the battery to power a solar scope mount, the temperature may rise due to being in the sun. Again, an insulating box will help slow down heating. Though it is hard to imaging a UK day taking the battery up to 60C – unless it is left in full sun. Recharging after use presents different issues as the permitted charge temperature range is more restricted. 0C to +40C. Fortunately, the nature of lithium batteries, and the BMS mean that you do not need to rush to the charger immediately after use. Unlike lead acid, they survive being left discharged for a time. After a cold night it is a good idea to leave the battery indoors for a time to warm a little before charging. After a solar session, if the battery feels warm to the touch, do not start charge. These are simple precautions that will help ensure you get the best possible life out of the expensive batteries.

Very interesting stuff. I have just ordered the book mentioned by Olly. A work colleague has recounted a sighting from 50+ years ago, when school age. It was seen by a friend as well. The location was a residential street in a small town The weather was thundery. But it was not actually raining. There was a sharp noise. A crack. The ball, about 1/2 metre diameter was on a house roof, near a chimney. The appearance was a white glowing ball. It slid (rolled?) down the roof and fell into the garden. A high fence prevented further viewing. It is thought there was crackling noise associated with the ball. Yet another mention of someone who saw something, rather than a first hand report. Surely now we can expect sightings to pop up on security cameras, or quick fingered phone users. David.

Do your research on any mount before you buy. Try to get hands on experience or comments from someone who uses the mount. Although things have improved, goto used to be 'go somewhere in the general direction of' unless you spent big money. The sales literature often gives the impression of 1/ plant on ground 2/point and go 3/ enjoy the view. All done in seconds. The reality can be: 1/ Plant on ground. Feet sink. Struggle to level. Try to point north. 2/ Power on. Set real time clock. Confuse US/UK date format. May need to enter latitude/long. 3/ Start mount align procedure using up to 3 stars. Some of which are not visible due to trees, walls, etc. Try different stars. 4/ Select an object to view. Scope slews. Nudge to centre and hopefully view. If you spend more you can get a mount with GPS added. This enters time/date/location for you. Or you buy a mount/handset that has a battery backed clock included. If you have a permanent pier, levelling is done once when you build. Please don't be put off goto. It can be very good. Just don't always believe the sales literature. Hope this helps, David.

I did some beach observing when on holiday. It got me away from the island light pollution. Wide field time exposures with palm trees in the frame were unusual holiday snaps to bring back. Standing on a beach lounger was a good idea as the crabs kept investigating my feet.

At work we are on the end of a long very old copper wire running in a ditch. No doubt well corroded by now and it has been repaired in many different places. It used to be a 2 mile run from the exchange. An upgrade to 'fibre to the green box' means that we now have only 1 mile of ancient copper! Download can be a few MB on a good day with upload usually a bit at a time. An option is to change service provider online. Take out a domestic user bargain internet price. They don't ask you about use. The only disadvantage is that you can't get a VAT receipt. Otherwise they will do you proud. A Plus for the interNet provider - enough of a hint? We have partly solved it by buying a 4G data package. Expensive, data is around £1/GB monthly. But much faster than the corroded copper wire. We certainly understand why some businesses will not move into certain areas, or decide to move out.

If I go down the WiFi route, what’s the best way to get the WiFi onto the PCs, as neither have internal receivers. If there only one observatory PC, then a simple method is to use a wifi dongle (that has an aerial socket) into a USB socket. Buy a length of aerial cable if necessary, and of course the external aerial. Pay attention to waterproofing the aerial and connectors. Such are the fashions in the PC marketplace, the kit I used is of course long gone so I can't show you a link! For multiple PCs you can take a different approach. Grab an old modem/router with several wired network sockets and has an aerial socket. Have your observatory PC and the router near to your house PC and internet connected modem/router. In the router setup (they are all different) configure the box as a wired & wireless router/switch box. The exact method varies with equipment type. Not just minor variations. Setups and terminology differ considerably. If you don't do this regularly, you will like me find it hard work and won't get it right first time. I sometimes think that a cauldron, eye of newt and toe of frog are useful when dealing with networks. This is why you have everything one place - you can easily jump from one box/PC to another. Let your main router (connected to the internet) have control over device addressing. It is DHCP. Having sorted out everything in one room, get a high gain external aerial and put everything into the observatory. I'm sure there are others on SGL who are more knowledgeable on networks and routers and switches. They can guide you on the software, firmware changes, hardware dependent incantations, spells, rune interpretation and whatever else is required.

They look fantastic. Your woodworking is in a completely different league to mine. I hope to see one of your scopes at some point. Wishing you every success. David.

The price rise notification from FLO prompted me to push the 'buy' and 'price match' buttons on a Solarquest mount that I had been thinking about for ages. It is really good that FLO had the consideration to let us know the situation and give us a last chance at the old price, rather than just let the increase happen. At work I buy a lot of electronic components. Their price is significantly influenced by the US dollar and the Euro exchange rates. In the past year or two, the price increases have been much more than the few per cent we are seeing on Skywatcher. It seems likely that all astronomy products, from lens caps to £10K scopes, are going to be similarly affected.

All powerline type routers rely on putting a high frequency signal onto the mains wiring. If the wire run is long, the cable capacitance absorbs the high frequency signal. If there are any filters (sometimes included with surge protection) in the line, then powerline data vanishes. Always fit an adapter on the unprotected side of any socket strips, UPS, etc. The cable run to my observatory (a long steel wire armoured cable) completely kills powerline signals. As it it was borderline range for the wifi I fitted an external high gain antenna to the shed. This is a 30cm square plastic housing on the shed side. The signal improvement means I get reliable fast connection to the house. While it is obvious that indoor aerials don't work as well as outdoor, sheds can be awful. Wood contains a lot of moisture. The radio frequency used by wifi adapters is close to that used for microwave ovens - chosen because it is well absorbed by water. Throw away the shed and buy a fibreglass dome? Or buy an external aerial? It is also useful to get a wifi signal analyser software package to see if you are in a busy wireless area. I use a free download on a Kindle so can easily walk around the garden detecting signals from neighbouring properties and measuring their strength. Hope this helps, David.

Interesting stuff. I have never been near enough to space junk or meteors to hear them. A comment on noises that I have been reported may be useful. If you hear a noise AFTER seeing the object, then it is a genuine sound wave (physical noise) created by the object passing through the air. For example on a calm day I often notice that high altitude aircraft are flying significantly ahead of their sound. There have been many reports of sounds from aurorae. Observed by multiple people in a group, but not necessarily all members. This is put down to an effect caused by the aurora generating low frequency radio waves that can be absorbed in the body, triggering nerve impulses. These sounds are of course co-incident with the visual effect. I know that the ionised trails left by meteors are active in the radio spectrum (not radioactive!). Radio amateurs sometimes try to bounce/relay radio signals off meteors. Whether the ionisation can trigger low frequency radio waves like the aurora, I have no idea. To wesdon1. Was the (probable space junk) noise behind the object, or coincident? To Alan. Are you able to say if your meteor noises are behind the object? Fascinating stuff. David.

If weight is important and you have funds, and you want a solution that works safely out of the box, use a Tracer power pack. If you want to save money then a lithium battery car jump start can be good. You need to arrange your own (low cost) fusing and connectors. If you have the skills this is a very affordable method. Lithium is typically 1/3 the power to weight ratio of lead acid and has good current delivery for power hungry dew bands. Hope this helps, David.

Apologies if I am missing something here skimming through the posts. Why not think about another mount for the bigger (probably newt) scope? If you are using the big scope (whatever it turns out to be) to look at (not image) DSOs, then you have some options. Is goto essential? Some sort of motorised tracking enough? Encoders on only on a dob mount? Even a push basic dob. What I'm thinking is for example, you can pick up (used) a SW200P, then a suitable mount like an EQ5, or similarly weight rated AZ or similar. This splits the hit on the wallet into two chunks and you could well end up with a good package for less than you expected. I have been very happy with high power contrast on the 8" newts I have owned (OO & SW). There is room for contrast improvement on the basic newt scopes by a bit of flocking. An older newt may have a basic focusser, but they are easy enough to swap. A Mak Newt with small mirror will give refractor like contrast. But they are heavier than basic newt. Hope this helps, David.

I would really like to try to grab a picture of a transit. Where do you get the path information? Thanks, David.

Sorry to say Makerbot are still extremely secretive about their printers. Filament detection is very good. You can walk away from a long print confident that the extruder will handle jams, slips and 'no filament' conditions most of the time without scrapping the model. We often leave our printers running overnight, with a UPS to handle any power cuts. But the secrecy means the printers do not use gcode or anything else open source. There is no facility to add (for example) a pause command at a particular line. If you to change colour, you have to be ready at the right place, hit the pause button, then change filament. The same goes if you want to embed a part (like a nut) inside a model. Once you set the printer running, there is no facility to adjust print speed, filament feed rate or print temperature. I very much doubt that our next work printer will be Makerbot. At home, my Colido DIY printer (around 1/10 the cost of the Makerbot Replicator) is completely different. The basic extruder means it will happily print 'fresh air' if the filament jams. However, it uses gcode so you can insert a pause at a particular layer to allow a filament swap. If you want to change printer settings on the fly, you can. I sometimes adjust speed, filament feed and temperature during build if I don't think the model is coming out as good as it might. Print quality is marginally down on the Makerbot. I really do mean marginal, not immediately obvious. But as I usually make brackets, jigs, etc rather than ornaments it doesn't bother me. Hope this is useful. David.

Thank you Stu for the excellent chart. Proof that my failure to see planets not entirely a consequence of trees and hedges growing around me! The chart gives me the incentive to ensure I have planetary viewing equipment ready. Or maybe I can continue to say sorting that mount, or scope, or camera can wait till next week, or month, or year!

At work we have Makerbot Replicators (yes one up from toys I know). The extruder detects when out of filament and pauses manufacture. We have the printers connected to our internal network, so the relevant person gets a desktop notification. Doing this means we don't have to worry about whether there is enough material on a part reel. I keep thinking about adding filament loss detection to the Colido DIY model I have in my garage, but never get around to doing it. A mechanism to detect filament loss is easy enough using a small optical detector either side of the filament. I have yet to work out how to pass this signal to the controller. It always seems easier to be pop into the garage and keep an eye on how much is remaining!

I have often seen geese flying over my home, in groups, after dark. Usually I have been alerted by their calls, then looked for them.

From a chronic equipment hoarder who likes choices, here are my thoughts. Lookout for a used EQ5 or similar size/payload goto mount. This will easily carry either of your existing scopes and the improved stability will hopefully let you get some longer exposure images. That is not just planetary. You could look for a bigger mount HEQ5/EQ6) but costs go up and if you have to do a lot of shifting and packing away, it becomes more of an issue. If you can have a permanent setup. Go for a pier and add the biggest mount you can afford. After doing this, if aperture fever is still diagnosed, look out for a used 8" newtonian. They are on sale quite often as a lot have been sold. You might even get something at a good price on a dob mount, so you just need some rings to drop it onto the EQ5/6. An EQ5 will even carry a 10" newtonian for visual use. But for photo use you will need a no-wind night. Enjoy choosing and using. David.

Good advice from Russ. My general thought on mounts is to buy the biggest mount you can lift and handle, subject to the size of your wallet. This gives you the most options on scope swaps or upgrades. The mount/scope combined packages are often based around the minimum mount the manufacturer can use. We tend to look more at optical specification than the physical details of the mount. Some years back, some manufacturers would offer an 8" reflector (think here SW200) on an EQ3 mount. This would be quite wobbly. Later manufacturers started putting this size scope on EQ5. Some people these days say that HEQ5 is a minimum size for astrophotography with SW200 size scopes. You have already established your viewing patterns. You know where you store kit and how many flights of stairs you have to deal with, etc. An EQ5 size/weight is OK for one person to handle. Beyond that you might want to split mount and tripod. Try to get a hold of and lift a few mounts to get the idea. Hope this helps, David.

Gutted to hear of your problem. As I don't know precisely what equipment was affected, and to what degree, I can only offer general advice. First remove all electrical power. Yes the mains is obvious. But you also need to remove any batteries. Even small (clock backup etc) batteries can start providing electrolytic corrosion. Anything electrical or electronic - dismantle it. Thoroughly wash out using a mixture of isopropanol and water. This will ensure you are left with a clean liquid that evaporates easily. Then leave covers off and let gentle and the dehumidifier do their stuff. Be patient (days if necessary) and don't worry about taking a hair dryer to electronics. It will survive 50C and more without issue. Mechanical bits. Bearing on mounts, etc. Wash out using isopropanol and water. Look at regreasing anything not sealed. Scopes and other optics. Wash the accessible surfaces as above. Dismantle on ly if there is evidence of water ingress. This is potentially more complex. Good luck and keep us posted. David.

If I had paid money on the basis of the web site, I would be worried. https://www.jtwastronomy.com/products/mounts/trident To produce the 3D rendered drawings, you only need a drawing package, not the actual product. If spending the best part of £4000, I would want to see some reports from users. There are also statements that worry me. Like encoders that the client can add for himself. Not for ££ extra you can have encoders fitted. This could well be an excellent mount. It all depends on whether you can wait for delivery. Then accept potentially the need for updates/upgrades all too often associated with new products. If I lived 100 miles from the factory, then maybe I would go and have a look. Then depending on what I saw, I might risk the money. But being in another country, I think I will play safe. My alter D6 still has life in it. Apologies for the negative sounding post. David.

Yes he influenced me. Even at junior school there was one of his books I read. Not mentioned here was the time that Sky At Night was on the TV. As a child, I wanted to watch the programme but it was always really late at night. I had to wait until I was little older. I'm talking here about programmes tranmitted for 405 line black & white TV. Pre colour broadcast. Pre VHS/Betamax videos. Never mind this funny interweb and BBC iplayer.

Los of good advice from the above. You are of course having lots of (possibly new) words thrown at you. Maksutov, Dobsonian and more. I feel information overload is impending. It happened to me when I first asked about an astronomy scope! Why not spend a couple (or more) evenings at an astronomy club? Members will usually be happy to discuss their choice of scopes. Maybe let you take a peek through. The club may have it's own scopes. There is (in my view anyway) no substitute for 'hands on' with any scope type and talking with owners. Hope this helps, David.

I wouldn't jump in to a new mount just yet. An important consideration is how and where you use a scope. Next is how much do you want to spend. As a general rule think of the biggest/strongest mount your back will handle for setup & packup. But size potentially limited by your wallet. For example I could recommend the D6 mount I use. It would not break into a sweat with a 180MAK. It will handle up to 40Kg of balanced scope. But at 35Kg for the mount + counterweights + 35Kg tripod, you can see why it is fixed in my observatory! Are you a back garden observer? Do you go to dark sites in a car? Have to carry down a flight of stairs? Having got a feel for weight and cost. Do you want to take photos? Sorry no instant 'definitely recommend' answers. David.