Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.



Advanced Members
  • Content count

  • Joined

  • Last visited

Community Reputation

346 Excellent

1 Follower

About Alan64

  • Rank
    Proto Star

Profile Information

  • Gender
  • Interests
    ...astronomy, naturally.
  • Location
    Mid-South, U.S.

Recent Profile Visitors

1,915 profile views
  1. Alan64

    First scope

    For the record, the diagonal you purchased is a great find, but it contains an Amici prism, which is suitable primarily for daytime use. A star-prism, or star-diagonal, is best for use at night. But you can use the one you got for night, too, as well as during the day. The only disagreeable things about an Amici-diagonal when using it at night is that when viewing a bright object you may see a bright line running through the center of it; Jupiter, for example. Also, the field-of-view may be somewhat narrower, when compared to a star-diagonal, but I think that only applies to faster telescopes than yours. I have two Amici-diagonals, and I'll need to test them with my telescopes to know for certain. Nonetheless, it's a very good find, indeed.
  2. Hi John, But that image does not show the enormous distances between each planet; only the sizes in relation to one another. But you can see that Neptune and Uranus are a good bit smaller than Saturn and Jupiter. Earth is about 150,000,000 kilometers from the Sun. That distance is known as an "Astronomical Unit", or AU. Saturn is 10 of those away from the Sun, but we get a good view of it through our telescopes because it's so large. Uranus, being much smaller than Saturn mind you, is 20 AUs away; twice that distance. Neptune......is 30 AUs away from the Sun...4,500,000,000 kilometers; a staggering distance, three times that of Saturn's. Given Neptune's relatively small size and enormous distance away, it makes it very, very difficult to observe it as large as we see Jupiter and Saturn, under high magnification, and with our relatively small telescopes. I'm thinking that you'd need an observatory-class telescope to see Neptune as up close as you would like... The mirror of that telescope is 5.1 meters in diameter. Yours is 200mm, I gathered. To see Neptune as large as possible with your telescope, the telescope must be collimated to near-perfection, the mount's motor must be turned on, tracking the planet, and with a 1.6mm eyepiece in the focusser... https://www.firstlightoptics.com/vixen-eyepieces/vixen-hr-planetary-eyepieces.html ...and for 625x. It wouldn't be impossible to accomplish.
  3. If you get the 9V-battery motor for the RA-axis of the mount, to automatically track, you will be able to increase the magnification, and up to the resolving limit of the 90mm aperture. With the motor tracking, the mount will not have to be adjusted and touched so often. It will make for steadier viewing... https://www.teleskop-express.de/shop/product_info.php/info/p395_Skywatcher-Tracking-motor-for-EQ-2-mount.html Then there's the deluxe motor kit with a hand controller, but I don't recommend it as the speed cannot be adjusted whilst tracking... https://www.teleskop-express.de/shop/product_info.php/info/p2934_Skywatcher-Quartz-controlled-RA-axis-tracking-motor-for-EQ-2-Mount.html It can be adjusted on the 9V motor, to fine-tune the speed whilst observing; keeping an object perfectly centered and standing still there in the eyepiece, and for matching the speeds of the Sun vs. the Moon vs. everything else. You did well in choosing a 90mm over a 70mm... Enjoy.
  4. I watched the video; not a bad kit. The eyepiece appeared scratched-up, and with debris on the lenses. Is the mains lens, at the front, similar? That could be your problem. The diagonal of your kit probably contains a mirror. Check the mirror inside as well. I've taken eyepieces apart before and cleaned them; the main lenses, too. Do you feel comfortable doing that? The main lens at the front could be very good optically, but I would upgrade the diagonal and eyepieces, if it were my own, and then go from there. Here's a good star-diagonal... https://www.rothervalleyoptics.co.uk/celestron-90-degree-star-diagonal-125.html Eyepieces, diagonals, etc, are fully one half of the telescope kit. You can't use a telescope without them, and you can use those items without a telescope. Therefore, if the mains lens, the doublet, is of good quality, or better even, you want those items to be as well. Here's an achromatic-doublet, like your own, that I cleaned up a while back... But that's from a much older kit, early '60s I think, if not the late '50s. I can't stress enough the need to check out the doublet. If it's of good quality, then the only way to test it is if the eyepieces and diagonal are in good order.
  5. I have the little brother to the kit in question, the Celestron "Astromaster" 70 EQ... But I was after Synta's deluxe version of their copy of a Japanese EQ-1, a Celestron CG-2, primarily if not solely. The refractor, to me, was thrown in as a bonus. In any event, you cannot purchase the mount separately I've been improving the refractor; and will soon be improving the EQ-1, taking it apart, cleaning it out, regreasing it, and perhaps to add some vintage wooden legs for the tripod, depending. I've got a new old-stock set of them from a kit I picked up off of eBay. The EQ-1 is too small, however, to carry about a 70mm f/13 achromat. Instead, I'll be placing my vintage 50mm f/12 achromat on it, and what I call "The Floating Achromat"... I even got a wee 9V motor-drive for it, too. Your mount is the Celestron CG3, an EQ-2. A bit larger than the CG2, but capable of carrying larger and heavier telescopes. Yours will be more versatile than my own, in that regard.
  6. Alan64

    First scope

    I found an image of the kit during the interim... I'm most familiar with that type of mount, a yoke-type; not bad, not bad at all. It is possible to replace the focusser, and one that would accept 1.25" oculars. If it says "Japan" on the focusser's specs-label, then the main lens should throw up rather sharp images.
  7. Alan64

    First scope

    To see any object in the sky at its largest, the shorter the focal-length of an eyepiece required. The magnifying limit of a 60mm aperture is about 120x, but under a cooperative atmosphere you might be able to push it up to 150x, perhaps. The telescope's focal-length: 800mm... 800mm ÷ 150x = a 5.3mm eyepiece, or a 6mm for 133x. The steadier the mount, the easier it will be to keep the telescope aimed at the object at high powers. What's the mount like? Take a snapshot of it and post it for us to see. We may be able to help you with it.
  8. You may need to back off the locking-screw(s) to insert an eyepiece, and don't tighten the screws too much after it's inserted. That's a very nice kit to receive out of the blue; congratulations. The mount, the EQ-2, is an equatorial, and for tracking objects with the slow-motion controls. You can track objects automatically with a little 9V motor attached to the RA-axis... https://www.rothervalleyoptics.co.uk/skywatcher-ra-economy-drive-for-eq2.html It takes just one wee 9V battery to power it. With the motor attached, you can keep any object centred in the eyepiece, standing still, and for however long you'd like.
  9. Alan64

    First scope

    I have a Zhumell Z100, which is the same as the Orion. They're all made overseas, then branded with this name and that once they arrive at market. It's a 100mm f/4 Newtonian, and with a 400mm focal-length. I got mine as a specialty wide-field telescope, for low-power observations mostly. It would be rather difficult to achieve the higher magnifications in order to observe an object up close, like the Moon and planets. You'd need roughly a 2mm eyepiece to view an object at 175x, for example. The consensus' 130mm f/5, the Sky-Watcher "Heritage", has a focal-length of 650mm, a bit longer, and where a more realistic 4mm eyepiece, or a barlowed(2x) 8mm, would result in same: 175x. With the 130mm, it would be more well-rounded, and for observing most everything in the sky, at low-power and high-power, both. That's why everyone is recommending it over the Orion, and I can see their point. Also, the Orion 100m f/4 cannot be collimated, aligned, in a conventional manner; whereas the 130mm f/5 can be, which makes it much easier to get the best images possible. I had gotten my 100mm f/4 mainly for observing one and only one object: the galaxy in Andromeda, and with a 30mm eyepiece at 13x. But even at that low power, the galaxy still cannot be viewed in its entirety, as a whole. I will tell you this, though: the Moon at 13x, with the 30mm in the focusser, is breathtaking.
  10. Alan64

    Should I buy?

    Sounds like a winner, tiger.
  11. Alan64

    Should I buy?

    Sounds to me like a 40mm-aperture telescope with a maximum magnification of 40x, made in Japan possibly, and a zoom-'scope to boot; a bit vintage. I take it you've seen one advertised. You'd see even less with it than you would with the National Geographic 76/700. How much have you budgeted for your introduction to astronomy?
  12. Alan64

    The Synta Wonky, Plastic Focusser Fix

    For this fix, six strips of PTFE were used. Before I cut the strips to size, I treated one side of the long strip with a flame from a mini butane torch, passing the flame over it, back and forth, for a few seconds, and in the hopes of increasing the surface tension for the adhesive, in this case the double-sided tape. I tried the 0.020"-thick PTFE out first, and with scraps of that inserted loosely between the drawtube and its supports... But I could only insert those for two of them, not all three. So then I knew the PTFE would need to be thinner. In went the 0.015"-thick next. Success... The three supports on the interior required just three strips of 0.015"-thick PTFE, and the double-sided tape, as did the two of the outside supports and marked with green arrows... The outside support at the top, the oddball, required a strip of the 0.020"-thick PTFE, the double-sided tape, and two strips of the aluminum tape, stacked. It required that in order to bring its level up to the level of one of the interior strips just behind it... I placed the strip in between the molded runners, and above them in the process, thereby eliminating same. Now, the drawtube racks in and out, smoothly, straight-and-true, and with no slop whatsoever(as there was before the fix)... Afterwards, I checked the collimation; not bad, I think... But yes, it could be better, of course.
  13. Alan64

    The Synta Wonky, Plastic Focusser Fix

    On the side, I thought that the interior of the focusser's housing was a bit too reflective, so I blackened and dulled it with a rattle-can of ultra-flat black paint, whilst carefully masking off the surfaces of the supports and the channel for the drawtube's rack. I used the blue painter's tape for that. You also want to ensure that no paint lands on the outside areas of the focusser, the supports, and in general... I also went ahead and spritzed the inside of the drawtube, as well as blackening the bevelled end of the drawtube which points towards the doublet-lens at the front of the telescope... The tip of the rack was blackened, too, there at the bottom of the image. *NOTE: In addition, you want to clean out and away all of Synta's original "glue, and what they try to pass off as lubrication, on the rack of the drawtube, between the teeth even, the gear of the pinion-shaft, and everywhere else, throughout. During this project, I replaced the "glue" with Super Lube , for example, a Teflon-based lubricant.
  14. Alan64

    The Synta Wonky, Plastic Focusser Fix

    On the flip-side of a five-pence coin...<flip>...we have Synta's wonky, plastic focussers equipped on the refractors, too; gads. The Celestron "AstroMaster" 70 EQ, a 70mm f/13 achromat, and seen here perched upon my AT Voyager I alt-azimuth... ...and brimming full of promise and devil-may-care; more of the latter I expect. It all started when I had wanted an EQ-1 mount, and for my vintage 50mm f/12 achromat. I could have gotten the bog-standard EQ-1, in black and silver, but the mount's interfacing with a telescope is not up to current standards, but doable if one is so inclined. Standing out from that was Synta's zooted-up version, the Celestron "DeLuxe" EQ-1, which comes equipped with a Vixen-type mounting interface; and about time, too. But the deluxe version is not sold separately. If you want one, as I did apparently, you must include one of Synta's Celestron telescopes along with it. I didn't want one of Synta's Jones-Bird simulations, as I have enough work to do, so I chose said refractor instead. Much simpler, no? No, not actually... The refractor's focusser... This is not your typical plastic focusser for an imported refractor; the focusser's housing... It looks like a spaceship, and one of those 3D printings to boot. What will it take, I wonder, and for a smooth, slop-free, straight-and-true racking motion. The interior... There's another one of those pitiful, plastic, self-adhesive glides, and the only one within the entire focusser. Note the three drawtube supports. On the outside, we have these three supports, in addition... The top outside support is unique, in that it has molded runners... Next, the fix...
  15. Alan64

    The Synta Wonky, Plastic Focusser Fix

    Said experiment resulted in no difference between using the epoxy or double-sided tape for the adhesive. Again, when the PTFE was pulled parallel to the substrate, it wouldn't budge. But when pulled straight upwards. it peeled right off. I am now looking into the possibility of increasing the surface tension of the PTFE, by passing a flame over it, and from what I had read online. In that case, scoring the surface of the PTFE might not be done, unless I scored the PTFE before the flame treatment.

Important Information

By using this site, you agree to our Terms of Use.