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calibos

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About calibos

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    Star Forming
  1. What I did was pluck the shape down to the base of the case. Pull out the whole piece. Cut piece in half and place that half back into the empty space. I then used some black baize I had lying around to cover the foam with. I'll eventually replace with Black Satin.
  2. Cool. One thing I realised about all this future tech never mind current tech like smartphones and iPads etc is that I will feel like I look like a **** using it until its ubiquitous and won't feel safe until it is cheap as chips and ubiquitous. What I mean is that like bluetooth earpieces where I couldn't wait till this 'Star trek Uhuru' tech became a reality, when it actually came, the 'reality' was I felt like an idiot talking to myself The safety aspect would be where as cool as it is to be able to watch video, read an ebook etc on public transport on the commute to work with an iPad, I realised I would never do it for fear of being mugged. So until these gadgets are cheap enough and ubiquitous enough that they are not worth mugging you for, then I am afraid that as cool as they are, I will probably never use them to their full potential.
  3. Unless you know something about the OP's requirements that I don't this could be incorrect advice. Can the OP control a fancy Temperature controlled motorised focuser and filterslide, guide cam and capture video/subs from a CCD cam to his tablet?? NO. He would indeed need a laptop for any and all of that. Can the OP wirelessly control his Synscan mount from Planetarium software that is as fully featured as the desktop version, on his Tablet. YES! The advent of fully featured planetarium software on a handheld device with large screen is a game changer. Yes, we've been able to control our mounts from such software on a laptop tethered by a cable to a laptop for years now. Finally however, we are liberated from the cables and the bulky laptop and can intuitively control the scope with a touch interface on a screen that is big enough to be usefull but not so big that its a chore to carry. OP should also search youtube with the terms: iPad Sky Safari for several more videos.
  4. I ended up buying them all last year after a confluence of events made it possible. I happened to have spare funds at the time. Televue were doing a 20% Sale. A particular US vendor had an active 11% online discount code doing the rounds. The Dollar/Euro exchange rate was $1.45/€1.00 I had relatives in the states that I could have them shipped to, who would forward them on to me. I got them all for half the price they are over on this side of the Atlantic. Still a lot of money but I reasoned that at that price, they were actually a safe investment and if needed I would be able to sell them for more than I paid for them for years to come, so effectively the funds were just sitting in my eyepiece case and available to look through rather than sitting in my bank acount and available to look at (as a bank balance on my statements) That said, I only bought the full set because it was an 'investment'. I didn't need the full set and even Televue themselves don't really expect anyone to buy the full set. Al Nagler himself recommends buying 3 to cover a range of magnifications/TFOV's. Which 3 you should ultimately get depends on the focal ratio of your scope. For some that would be the 21mm, 13mm & 8mm and for others it might be the 17mm, 10mm & 6mm.
  5. Have a look here. http://www.cloudynights.com/ubbthreads/showflat.php?Cat=0&Board=reflectors&Number=5028653&fpart=&PHPSESSID= He used Moonlite clamps and ball and socket clamps for the top of the struts. I'll be converting my 16" Lightbridge from its current truss system to the collapsible 3 strut system. However with the greater Focal length and shorter height of my Lower OTA I'd be pushing the flextube type system (longer struts) beyond the point where it would hold autocollimator precision level collimation un-aided. As a result, I'll be adding a steel cable string tensioning virtual truss system. with a threaded bolt system in the struts so that I twist the 3 struts to tension the strings.
  6. It was and is my choice. ie. 16" Lightbridge with Servocat Goto Drive. I've had the scope since late '08 and the Goto since late '09 but life has meant the latter hasn't been fitted to the former even though its 2012. Have only had the scope out 3 times in that period. The reasons matter not. In the intervening 3 years I have seen the advent of the 16" SW flextube and wondered if I had made the right choice and seeing as I never got to use or finish the modding of the scope, I might have been better off having the money in my bank account for those 3 years and then bought the already put together SW Goto. Well, I've thought about it a lot and after I saw the Youtube video of the SW16 goto which showed its true scale, I realised that I had not infact made a mistake. From the getgo the LB16 is a smaller more manageable scope and more easily broken down for transport. With some reasonably simple mods it can be made even lighter and more managable. I am even modding mine with collapsible struts so I get all the pros of the SW Flextube without the downsides. So I would say LB16 with servocat just from the point of view of the scopes as they come from the factory. That combo isn't much if any more £££ than the SW16. If you think you might enjoy customising the scope, then it is a total no brainer. I'll end up with a scope with all the pro's of all the equivelent scopes with none of the cons of any of them....and I shouldn't be allowed near a jigsaw!! Watch this space in a few months. Plan to do all the mods over the Spring/Summer.
  7. I am not usually inclined to defend Journalists but maybe its their proofreading skills rather than ignorance of the non interchangability of these terms thats the problem. ie. Maybe they typed astronomers but he infernal spellchecker changed it to astrologist without them noticing.
  8. calibos

    I give up!

    Fog at Heathrow this morning delaying her Dublin flight meant my Mother missed her 11am connecting flight to Kuala Lumper on her way to Perth in Oz. Stuck in LHR till 10pm as they rebooked her LHR to Singapore and then onto Perth. She was not a happy camper on the phone. We've no idea where her luggage is. Someone told me they often send luggage on the previous flight, so her luggage could be sitting in Kuala Lumpar. She's not even going there now As for the Fog. Same here in Ireland. With the High pushing the Jetstream to the far north I knew the seeing would be good for the Jupiter Venus conjunction. I just thought that a high at this time of year meant clear skies too. Looks like the group observing seesion for the conjunction will probably be called off. If its not one thing its another. It takes a special kind of person to be an astronomer on these islands
  9. See here: Buy 40" New Technology Telescope (Alt-Az Folded Newtonian)
  10. The problem with Lead Acid batteries (SLA's) usually found in these is that they shouldn't really be drained below 50% or they start to lose capacity. So one may as well divide their rated amp hour capacity by two. You'd be much better off with a gel cell which can be drained empty without negative affects. I use a 20ah thats only about 3x7x8 inches IIRC that fits inside my rockerbox. Its also a bad idea to run a laptop off one unless one owned one of the behemoth 120ah leisure Caravan/boating types. The DC to AC back to 19v DC convertor needed to power a laptop off a 12v wastes a ton of power as if the voracious apetite of a laptop wasn't enough. Drain the battery and not only can't you use the laptop anymore but you can't use the goto on your scope either. Best to use something like a scope mounted 20ah for the scope drives, dew heaters etc which will probably last a few nights observing and won't suffer cord wrap by virtue of the fact that this battery without the Lamp, tyre pump compressor casing of these jump start types will actually fit on your scope base and not trail a cable. Then have a spare laptop battery instead.
  11. I'm pretty sure you are both talking about differrent things. M.Tweedy talking about dewshields to slow down dew formation on corrector plates and Haggis talking about the idea proposed by the OP which is wrapping the whole Metal OTA. The fomer is a good idea and the latter not so much. I don't think Haggis is necessarily in disagreement with you Michael. I understand Haggis' frustration though. One can't help but raise ones eyes to heaven a little bit when one reads something that one knows to be wrong written in an authoritive tone that may be taken as gospel by others. I too would research something comprehensively before wasted my time trying something never mind posting about it. However, I think you could have been a little more tactful Haggis' In the conventional Newtonian world its a good idea to insulate the inside of a metal OTA. Not to prevent dew on the OTA. Who cares about dew or frost on the outside of the tube. It affects nothing. The affect a super cooled metal OTA has on the scope are tube currents inside the tube. The cold OTA chills the air against the inside wall of the OTA below the ambient temperature of the rest of the air inside the tube and eddies of this colder aire roll off the inside of the tube into the lightpath causing bad 'Scope generated seeing'. With our open ends we don't have to worry about the whole airmass inside the tube going below ambient, just the eddies rolling off the inside walls. Insulation thus works for us without any negatives. For a sealed SCT its not so simple. The inside of an SCT can't reach ambient quickly with air exchange like an open ended newtonian (Putting aside the issue of primary mirror cooling, primary fans and boundary layer effects). The air inside can only cool to ambient (putting aside the lymax cooler solution) via conduction with the corrector plate and metal OTA (and from the outside of the corrector plate and metal OTA to space via radiative cooling). Insulating the inside or outside of the metal OTA prevents one or the other, leaving only the corrector plate to conduct/radiate, hence a longer cooldown and longer time till scope generated bad seeing is gone. The carbon fiber OTA's are not about insulation but to minimise expansion/contraction which can affect focus. Not much of a problem for visual observers but a big problem for imagers. Thus you are more likely to find imagers with carbon fiber SCT's. you will also find that these carbon fiber OTA owners are also aware of the insulation/cooldown problem of carbon fiber OTA's and 99 out of 100 of them will own a lymax cooler I'd wager. You do indeed run into the problem of the OTA and air inside cooling below ambient which can be as much a generator of bad scope seeing as the opposite, but the solution to one is not to invoke the other. Dew on the outside of the OTA is not a problem. Dew on the corrector plate is. A temp controlled dew controller like a Dewbuster, dew strap and dewshield is the best solution for dew on the corrector to keep it just above ambient. If I owned an SCT I would own the above. I would actually insulate the inside of the OTA as contradictory as it sounds with a thin layer of flocked cork(kill two birds with one stone)....but only if I had a Lymax cooler. ie. Be able to cool the inside air quickly to ambient bypassing the negative affects of insulation of an SCT OTA at which point the insulation becomes a benefit rather than a negative. It prevents further radiative/conductive cooling from chilling the inside air below ambient.
  12. The Spanish have forgotten what clouds look like. I check Sat24 every day. Haven't seen cloud over Spain since the big freeze they had.
  13. 'fraid not. Closer, but not 'Much' closer. 92 million kilometres as opposed to 102 million kilometres. 15.2 arc seconds across as opposed to 13.8. Not enough to really notice. in 2016 its enough to notice at 18 arc seconds across but unfortunately its in the southern ecliptic and only gets to 15º above the horizon for us. In fact all the apparitions where Mars is big have it at a low alt for us in the northern hemisphere. As always, the Aussies get the best views. ie. Large and high
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