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Carbon Brush

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    Ollerton/Tuxford Area. Notts.

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  1. If you tell us what mains adapter you were using, that might give us a clue. Ref comment by @Elp Much easier than diving into all the other potetial problems.
  2. A contrail comprises water, carbon dioxide and bits of soot. As the carbon residues are tiny particles how long is it before they fall to the ground? While carbon is in the sky, it will seed cloud formation.. I'm sure someone somewhere knows about this effect. I remember reading a long time ago about Australian farmers making daily reports on pan evaporation. This was on the orders of the government. Agriculuture department maybe? Something that started in the 19th century and continues today. Sorry I don't have all the details. The evaporation rate had gradually changed due to the sky being less transparent. I took a quick look to see if I could find the article. But no luck. Again someone may know more.
  3. Thank you for posting the article link. It is a much debated subject. At home I have a good view of a major high altitude airway. On a good day I can see a contrail start west of Liverpool (over the sea) and follow it beyond my Nottinghamshire overhead. I know where I start viewing by timing to overhead and assuming cruising speed, or more accurately using Flightradar 24 to track. Most contrails dissipate in tens of seconds, maybe a minute or two. Though on a few days, they can persist much longer. Then there is the question of dissipating beyond unaided eye view, and dissipating beyond heat retention. Think back a few years to the aviation shutdown caused by the (very long unspellable name) volcano in Iceland. We had a period of no commercial flying. I remember looking at the sky on more than one day after flying resumed, seeing contrails that were all but games of noughts and crosses in the sky! It certainly made me think about how 'clear' our skies are.
  4. The 12V to 11V 'step' indicates one cell (of six) has shutdown early. Equal performing cells would give a gradual voltage decay. A bit of unexpected bad luck if it was a known brand. Definitely battery to the bin. You should find the lithium battery is good for providing high current. The other good news (given UK weather) is lithium performance degrades gradually with charge/discharge cycles. not the calendar. In addition, the self discharge is far lower than lead acid. A good choice for the replacement.
  5. Some years back I converted an old Prinz scope to take (modern) 1.25" eyepieces. The not quite 36mm thread and Vixen adapter ring a bell. If I can recall the details I will add them. I do recall that when the fit was not quite right (couple of tenths of millimetres on diameter) I used a screw thread gauge as a scraper on the female thread to make things fit.
  6. Methods vary between scopes, but I think this generic explanation of why you have to buy an expensive scope for Ha viewing is reasonable. The Ha solar scopes initially filter out unwanted wavelengths. Starting at the objective and refining further down the scope. Rejecting unwanted energy prevents scope heating. They remove the IR, the UV and most visible, leaving a narrow red region. The narrow red is passed to the etalon. This is a really really narowband filter that is necessary to view the filaments. In addition, the actual wavelength has to be tunable/adjustable to get best views. Doppler shift - another word to introduce. Adjustment is by tilting the etalon, or by altering the air pressure inside, or by altering temperature. Tilt and pressure are immediate adjustments, temperature is slower. To get the etalon bandwidth into perspective, it is typically 0.1 nanometres (nM) pass. Double stacking reduces to typically 0.05nM. A visual Ha filter for night use has 50-100 times the pass bandwidth. So even if the energy rejection was done, it would not show the filament detail. All manufacturers have to select their etalons from a mixed materials bucket containing research grade, to landfill quality. It is the way the material turns out. This means if you get a report of first rate views from a scope type, if you go to buy another, it may be better or worse. In the early days of the PST, I read about someone going to a retailer and setting up on the pavement. Selecting from the 3 scopes in stock, and seeing very different results. In the early Quark days a lot of people returned poor quality product. At a show I asked how the complete Daystar Ha scope could sell for less than a Quark eyepiece. The retailer could not (or would not) provide an answer. HTH, David.
  7. Alternatively set them up, widely spaced, in a field. Call it the (Astrosoc name) Very Large Telescope Arrary. Oops - has that term been used elsewhere😁
  8. If you really want to spend on Ha, look at the Solar Observing section around Jan 2019. There are quite a few entries about when I was trying to upgrade from PST. Various discussions mentioned Quark, Lunt, Coronado, etc. Some of it is still relevant today. If you are happy to stick with white light, a Herschel wedge gives a lot of enjoyment for the ££ spent.
  9. Bolting the Vixen to the Losmandy as described by @RT65CB-SWL would be my first choice. I have access to good drilling and tapping tools so it is easy. Not having sight of the Losmandy bar I don't know if there is drilling involved. The only contra indication is if your mount is on the weight limit. Option 2 (again drill/tap required) is a couple of short lengths of ali bar (1/2" sq?) on the old Losmandy fixings to space the Vixen bar off the OTA. HTH, David.
  10. I think that depends on the individual. Yes nice to watch the old ones. Interesting to see (incorrect) thoughts on what the lunar surface was like pre-apollo, and more. But just as fascinating to see first far side of moon images, first Mars close up images, etc. I remember when first pictures came in of Saturns moon Japetus. Though that may have been on the news and later discussed on S@N. Yes a dark side and a light side - but no sign of a 'Clarke' obelisk😁 The current format requires lots of planning, large film crews, travel to distant locations, etc. How do you produce a programme that can report on recent events? If the show had a section based around someone checking up on recent events, jumping on a train to the studio and sitting in front of a camera with minimal props.... Oops - been there and done that. Thank you SPM for your many short notice reports. How can the current production method provide an informed presentation about (for example) the recent toppling moon landers?
  11. Lithium battery performance does vary between manufacturers and models. The table below is taken from data poduced by samsung for one of their cell types. may be useful for reference.
  12. This is yet another thread where a member has asked for advice and not returned since posting. If I had real concerns about possible kit damage, I would not walk away from the thread. On behalf of the OP I am going to thank all those SGLers who have freely given their time to offer good advice. On Sunday when I first saw the thread, I was on the verge of taking the covers off my S50 to look into routes for water ingress and how best to deal with it. But I was out all day. I am glad that I did not make the effort. It also makes me think that in future I should check post history before taking time to offer help or advice.
  13. The programme title is somewhat misleading. It suggests 'these are things to see in the coming month'. Rather than the big budget global tour. Very affordable technology could be used to improve on the early presentations where SPM sat at a desk with cardboard cut out planets and the like. No need for travel. Though it has its place to show us the new large telescopes, etc. Given that very few people around today saw the first (decade or more) programmes, much content could be repeated for the 'newcomers' who have only got interested in the last half century. I missed many early years of the programme due to it being way past my bedtime and domestic video recorders had yet to be invented. Then again. Why not just put more of the old programmes on iplayer.
  14. Thank you @Oortraged for providing much useful information. Particularly the long wait. I would add that if you have electronic equipment in pieces, a rinse using isopropanol is very good for removing left over water that may in nooks and crannies. For scope lenses, Baader wonder fluid is great for getting stains off.
  15. Only just seen this. REMOVE BATTERY. This buys time. After this warm air, radiator, etc with other covers off. In a rush sorry can't go into detail.
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