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alanjgreen

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About alanjgreen

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    Cumbria. UK

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  1. NOW SOLD to Hadyn
  2. Now reduced to £35 plus postage
  3. Now available for £1750. Great price for a great scope
  4. Paz, I too see the collimatiion shift if I rack out the focuser with the laser & tublug still in (after I have completed collimation with it racked in). I have a 2.5 inch travel focuser which is about 2 inch racked out under normal cyclops (one eye) viewing. Maybe I will try collimating with the focuser racked out at this position to see if there is further improvement to be had. I was worried about sag due to the weight with the focuser racked out plus paracorr2 plus tublug plus glatter 2 inch laser. I have a feathertouch focuser so maybe it will take it? Only way is to test it out... Alan
  5. Grumpy, plan to add a Nexus from AstroDevices, then add some encoders and a powered ground board. Then you have a push-to system to enable you to find objects. The nexus device creates a wifi network at the scope which you can connect phone or iPad and then use SkySafari to see the sky. after 2 alignment stars, as you move the scope, SkySafari moves with you. if you don't fancy doing this yourself then contact David Lukehurst and get him to make you a lovely dob to your specification it will cost more but it can be exactly what you want ! see www.dobsonians.co.uk or give him a call, he is a really nice bloke. Alan scopes can take 4 months to make, fyi
  6. See post from DRT in this thread, seems it just unscrews
  7. As you may know, I purchased a 20" f3.6 dobsonian earlier this month and I have now had a few short sessions with the scope. My initial findings were that I was getting better stars with the Baader MarkV binoviewer using a Baader x1.7 Newtonian glass path corrector than I was getting with the Ethos and Paracorr2 combination. I was getting on okay with the Ethos21 but the stars were really hard to focus with the Ethos 13 and Ethos10. The brighter stars did not come to a focus with four nice diffraction spikes. I did some reading up on the internet after my last session and found this useful document: https://www.cloudynights.com/topic/373440-collimating-a-fast-newt-with-paracorr/ It talks about performing collimation with the paracorr in place. I also found several contradictory articles saying that the paracorr should not be in while collimating. Anyway, as I own a Howie Glatter laser (with 1mm stop adjuster) which can be used with a paracorr, I decided to give it a go… I did some testing with the laser and a nicely centred laser without paracorr moves about 1cm when the paracorr is added. WARNING: If you decide to follow me then make sure your paracorr is not in position “A” when inserting the laser as the 1mm stop adjuster with hit the lens of the paracorr. I decided to use the mid-position “E” for my collimation as E21 uses “A” and E13 uses “H” I had the focuser racked fully in for stability then added the paracorr which stays in place for the whole collimation process of secondary AND primary adjustment. The laser dot is made larger by its journey through the paracorr but still shows up nicely on the primary. I adjusted the secondary to centre the spot then added the Glatter Tublug and adjusted the primary. I went around the loop again and made some more minor tweaks until all was stable with a good result coming from the secondary and primary. RESULT: I am happy to report a positive outcome, there is a marked improvement in stars and I am able to get good focus with the E13 & E10. M13 globular was much better. Much sharper image of Jupiter than I was getting before. Thoughts & Questions: 1. I do not know how many Dobs are out there of similar or faster speeds than my f3.6 and how many of those scopes are using a Paracorr2 with Ethos 100 degree eyepieces, but I would be interested to hear from anyone who has had similar issues with collimation (which is critical at these fast speeds) being affected. 2. This seems another reason to go for Glatter collimation tools as they are capable of working through a paracorr2 coma corrector. 3. It’s interesting that the Baader x1.7 Newtonian GPC did not impact on collimation the way the paracorr2 seems to ! Comments welcome, Alan
  8. I have the both skywatcher & astronomik UHC filters. The skywatcher UHC was my first purchase due to its cheaper price and it gave me good service. I can now compare it to the much more expensive astronomik and here are my thoughts. 1. the astronomik UHC is better than the skywatcher (you can see it at the eyepiece!) having a better pass through of non-UHC blocked light. It makes a better all round view. 2. the skywatcher UHC is good value for money. ( Note that I dont feel the same love for the skywatcher O3 as it is blown away by the astronomik O3 !!) So I say, buy with confidence - its a good filter and works well on UHC targets. If you want the best then buy Astronomik. HTH, Alan
  9. Here is a pic of my wheels & track. I have 5 wheels on both sides, riding on the galvanized track. Make sure your wheels are galvanized and have ball bearings inside for smooth motion. Purchased from "fhbrundle" (linked in a post below)
  10. Tim, i had one of these as my first scope, it was a great starter scope but now it is out of production I would go for something different if you are buying new. The starsense camera is the main bonus of the sky prodigy and makes setup a breeze. But doing a manual 2 star alignment is quite easy, so do consider the 150p star discovery. https://www.firstlightoptics.com/reflectors/sky-watcher-star-discovery-150p.html its much cheaper and has more aperture. The motors and tracking are there too, you just need to manually align it yourself. if you can get the sky prodigy for the same price then go for that otherwise save some cash and get the star discovery instead! Alan
  11. Version 4 manual http://www.nexstarsite.com/download/manuals/NexStarHandControlVersion4UsersGuide.pdf looks like you have to go into the alignment option BUT press UNDO to not accept the location. Then it should go into an amendment routine so you can change the location. try this twice, entering your location in both of the formats suggested. There seems to be some test alignment tips on page 11
  12. What you describe is a location issue! The scope thinks it is somewhere else on the earth. Northampton gps = Northampton, Northamptonshire, UK The latitude of Northampton, Northamptonshire, UK is 52.240479, and the longitude is -0.902656. Northampton, Northamptonshire, UK is located at United Kingdom country in the Cities place category with the gps coordinates of 52° 14' 25.7244'' N and 0° 54' 9.5616'' W