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wulfrun

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Everything posted by wulfrun

  1. It's a quick-blow fuse. I was about to ask what was on it but beaten by @Carbon Brush The F means fast, so it blows quickly on any surge/overload. I'd get a slow-blow/anti-surge type, it'll be marked T5A not F5A. EDIT: we may have found the problem!
  2. Ah OK, that adds to the confusion then! If the mains power supply works fine, then the mount must be OK with no power shorts. No need to start messing there. In that case, logically the 5A fuse is inadequate. It's not unusual for electronics to have a current-surge at power-on but I'd be very wary of just upping the fuse rating. What exact type of fuse is the one that blew? Is it definitely the recommended fuse?
  3. OK, kind of not unexpected. Next step is to get at the power leads inside the mount and trace back then. Once inside I'd expect an obvious short somewhere since you know the mount works. Sadly, it's not my area of knowledge and you'll have to wait for someone else to guide you on it. Before doing so, just double-check if the fault is present with mount switched OFF as well as ON. If it's still there with the mount OFF it pretty much narrows it down to the mount's power socket itself. If you power it from mains, are you still using the same 12V socket on the mount? Just realised that that would be puzzling if it works OK that way.
  4. Next step would be to take meter readings on the mount then (no power applied). Use the Ohms range and test both ways with the meter leads. If you can't easily get at the mount socket terminals, use your lead and test the cigar-end. Just to repeat...the powerpack is NOT used or connected at all for this bit.
  5. No, you're completely right, the mount draws what it needs (provided there's an edequate supply).
  6. OK, so everything was connected up before switching on at the powerpack? I'm not familiar with the mount, it'll have a rating marked on it...is a 5A fuse enough (I'm guessing it's plenty)? Use your test meter to check the lead first of all then. Continuity along both conductors, the polarity can be verified and no short between the conductors. If that checks OK, replace the fuse, plug the lead in and don't connect the other end to the mount. Switch the powerpack on and the fuse shouldn't blow. If all's well up to then, the fault is in the mount as some disassembly will be needed but let's see.
  7. First off, do you have or have access to a multimeter? It'll be pretty indispensable to have one and you don't need an expensive, all-singing one. Are you sure the lead delivers the correct polarity? When exactly did the fuse blow? Was it when you plugged it into the power pack, when you plugged the other end into the mount or only when you switched the mount on? What's the rating marked on the blown fuse? (Not what it should be, but what it actually is). You need to troubleshoot methodically to find the fault and the first thing to note is NOT to keep replacing the fuse and blowing it again, you may well do (more) damage.
  8. Well founded scepticism, I suspect. One problem would appear to be generating enough electrical power, which got no mention. I'm not convinced it'll work in space on "virtual particles" either. The video seemed very fanciful with too much dreamy music and too many cgi, futuristic-looking ships and no demonstrations of any working reality.
  9. MHD is a thing, it's been been known about for a long time. Nowt wrong with that aspect from a science point of view. Whether it's useful & practical in this application is a different matter. Seems to me that all our ideas so far involve throwing "stuff" out of the back, at as high a velocity as possible. I'm aware that we don't know of any alternatives but it's a severe limitation since you have to take said "stuff" with you (on a practical basis and at least to start off). Perhaps this is where the next leap will be, with either new physics knowledge or lateral thinking. I can't see how serious speeds can be attained without a new concept, which means we're stuck at the not-yet-practical stage for covering astronomical scales of distance.
  10. Guilty as charged...one of those instances of engaging fingers before brain!
  11. No problem, I'll go hang my head in shame 🙂 Even more so as I also use a full-aperture filter!
  12. Yes, I realised what I'd put and removed it. Too late, you quoted too quickly!
  13. I spent best part of three hours looking (mostly) at Saturn and Jupiter, I got the best views so far this year. I had the 150PL out. Started on Saturn since it was further south, higher and nearest towards disappearing behind the neighbour's roof. I used a 9mm to start with, in which I could just make out Cassini and what looked like the ring-shadow or banding, not sure which. Titan was easy and at least 4 other moons were visible, either directly or with averted vision and at least some of the time. I upped the mag with a 6mm planetary EP, which pretty much lost me the smaller moons but made the Cassini division a doddle, if a little wobbly, though it took the power pretty well (x200). Moved on to Jupiter and went back to the 9mm, which just got me all 4 of the galilean moons in the FOV with some spare framing. Banding was obvious but no sharp detail and no GRS around, sadly.I did try the 6mm but the view got worse so I stuck to the 9mm. I noticed one moon getting (visually) closer to the planet, assumed it was Io but nope, checked later and it was Europa. Carried on watching and eventually was rewarded by what I thought was a black dot on Jupiter, the moon's shadow, around 12.30am. By 1.30am it was unmistakable, maybe 1/3 of the way across and Europa was about to be swallowed by Jupiter's glare. Getting a bit late so I thought of packing up but then realised Mars was well over the rooftops so I had to look. Sadly it was still in the "mush" zone so not really anything to see beyond a red blob. I fancied the colour wasn't even north/south but that might well just be atmospheric effects. I consoled myself with a quick look at the Pleiades and Hyades, above and below Mars and then packed up.
  14. Interesting that they've gone for AAA batteries rather than AA, although the Telrad's AAs last so long there's a risk they'll leak before you actually run them down. Can't say I like the styling (personal opinion) but if it functions well you don't have to see the styling in the dark! How does it compare on price? And does it have built-in flashing mode?
  15. Ask @DaveL59 where he got his copper tape for his lens repair, covered in this thread. There may be thicker/wider grades available (what he used is probably too puny for your idea):
  16. I'm not 100% sure of this but you can probably get copper tape, maybe even adhesive-backed. As long as it's a suitable size for the current involved. You could put it on something like pvc water pipe to make the support & diameter. Then you'd just need a spring-copper strip to make a contact brush. Just some ideas to throw at you.
  17. It'll probably work moderately well (at first) from an electrical viewpoint, other than some voltage loss. However, aluminium with steel balls? What was the designer thinking? No! Any damp (a bit inevitable with astro gear) will give you pretty nasty galvanic corrosion. Add in power transfer making things worse. I predict a short life, sorry, hate to put a downer on an otherwise neat solution. Why not knock up copper slip-rings with spring-copper contacts?
  18. Just spent a couple of hours on the planet's (mostly). Somewhat impromptu since the forecast wasn't promising, so I only had out the Heritage 114P Virtuoso. Saturn looked better than of late and I bagged more moons than ever before. Checked afterwards and it was Titan and Hyperion that were easy spots but maybe three others were popping in and out of visibility. Stellarium showed them later to be Rhea, Dione and Mimas (if I didn't imagine that one*). Hints of Cassini division at times, which was equally as unexpected in the little dob as the moons I seem to have ticked off. Jupiter was accommodating too, three moons with what I thought would be Io hiding but Stellarium put me right that it was Ganymede. I thought I might have *just* detected the GRS and once again a later check confirmed it in the right place, another first even if it was rather vague. Next I put Neptune into Synscan and was rewarded with a tiny blue dot. I adjusted in and out-focus to confirm it wasn't a random star. Pushed my luck with a 5mm + 2x FE and got a bigger and blurrier dot, not unexpectedly! Still, I've seen it. Lastly I stuck a 16mm Nirvana in and had a look at the double cluster, amazing as ever. Then the inevitable, gobs of wispy and not-so-wispy clouds came over. Mars was just coming over rooftop level but the little dob wouldn't have made much of it and the conditions (and time) were against me anyway so I came in. * edit...further checking suggests it probably wasn't Mimas, hey ho.
  19. Section 102 of the Clean Neighbourhoods and Environment Act covers light trespass. If the light intrudes into your bedroom, you probably have a better case, so mention that before mentioning astro.
  20. Another star? Looks like it could be. What star did you use?
  21. I was in my mum's garden, set up with a film camera, the longest lens I had (probably a 210 and maybe a 500mm) and a welders glass gaffer-taped over the objective. Shot most of a roll of slide film, something like 2 or 5 minute intervals, can't recall. Yes, I did peek through the glass (didn't know any better) to determine when to start shooting. In my defence, it was a film SLR with a metal-bladed shutter so worst-case I might have melted the film if my "filter" failed. We weren't quite in totality here but it was a warm, cloudless day (unlike Cornwall!). At maximum eclipse it went really dull and was distinctly cooler & had a very eerie feeling.
  22. Nice find. I used to collect former-USSR rangefinder cameras (yes, niche maybe!) and still have several. They often get slated for poor production quality, sometimes justifiably but their optics were always good designs by the contemporary standards. I still have quite a few lenses and they produce excellent images. Your bins possibly won't be multi-coated but I bet they perform really well. Enjoy!
  23. There are several similar designs and I haven't noticed complaints about lack of stability. Personal experience with mine suggests the mount is quite adequate, provided it's placed on something substantial. On a wobbly table, well no surprise it'll be wobbly.
  24. The mount is pretty solid board. I've just weighed mine at 7.45kg total, with finder but no EP. Just the OTA + finder comes in at 4.05kg, so the mount must be 3.4kg. Add a hefty EP and it's pushing the limit.
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