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AlentejoSkies

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Everything posted by AlentejoSkies

  1. Nice write-up. Enjoy your new focuser. I think you will be delighted with the difference!
  2. Great thread. Thanks. As I will soon have a nice 8" f/6 mirror set in the post thanks to @Stu, I've been giving a bit of thought to putting together a dob optimised for binoviewing, and was out again last night trying a few eyepiece combinations with the kit I have to see if this is the way to go. Here's a few rambling notes from last night's testing... Targets: Jupiter and Saturn. Site: Alentejo, Southern Portugal. Scope 6" f/8 homebuilt dob, WO binoviwers, a couple of glass path correctors (GPCs) In the last four years I've put some effort into learning about and using astronomical optics - and I already had a good professional background in optics. I've learned a lot, but what most amazes me is what I see through the eyepiece now using actually the first equipment I bought and made. When I first built this scope I was impressed to see faint lines on Jupiter. Now I see swirls and patterns, a wealth of colour. The question is not whether I can detect the GRS, but how does it look tonight. The globe is full of features. What once looked like an aspirin now looks like a photo with character and characteristic. I have acquired quite some equipment since those first days, but I'm talking about using exactly the same setup as I started with. The only thing that changed there was me. And a lot of that had to do with getting comfortable and using binviewers. Anyway, I was actually checking a few eyepiece combinations, bino versus single. First test: Televue 15mm Plössl on one eye, Vixen 15mm NPL on the other. 2 X GPC correctors for a total magnification of about 220. I can only reach focus with stacked GPCs at the moment. Next scope should be different. Hence the experiments. These two 15mm Plössls are not parfocal, but with a bit of fiddling around, I was surprised to find it works. The difference between the two eyepieces was minimal center and edge. I could convince myself either way which was better, and will keep that question open for now. What was obvious is that the Plössls were way better off-axis than the WO 20mm pair that came with the BVs, that I usually love. On these planets, I just love the immersive view of two eyes. I can watch the planet move across the field of view again and again. One-eyed viewing for me seems technical in comparison. But then just as I was convinced again that nothing beats binoviewing, I did try a nice little 9mm volcano top ortho with one GPC srewed directly into the bottom to more or less match magnification to the above pairs. And then I had to admit that there was clarity and detail there that was not with the combinations I have available for binoviewing. Tried to see if that still held true if I just used half the binoviewer and my one ortho, but the need to stack GPCs gave too high magnification - horrible. Not a super-fair test as the unmatched magnifications makes a big difference in itself. But this morning I couldn't resist buying that second 9mm Ortho that's been on ABS for a while! Let's see what happens with two! And the next scope will definitely be built with some way of setting up for binoviewing with and without GPCs. Will try tonight with the ETX-105. Totally different beast, but it has a much larger range of focus and can handle binoviewing without GPC.
  3. I tempted too - by the mirrors. Local school has been asking me to build a telescope with them for a while, and I'd have a good reason to try printing a focuser. Let's see if we can work something out...
  4. Thanks for the link. I may very well do that at some point. But somehow the psychological price border for something I don't really need (had never considered it before yesterday) seems to lie around the 20 pounds mark today!
  5. Just missed the one that Mark was selling yesterday, but already got interested. Anyone else out there selling a Ronchi eyepiece? Thanks, Douglas
  6. So, to follow up: This thread can be closed. I did the job - dead-easy, thanks John - but immediately realised that the focus rod is stiff. I'd never noticed before, but now it was obvious. Torsion would build up in the cable until it was enough to overcome stiction and then suddenly it would make a half-rotation in one jump. Gear cable wasn't even strong enough not to uncoil in the one direction. The brake cable fared better, but I think flexifocusing is out of the question until the focus itself is smoother. I'll see about stripping down and regreasing sometime soon. Looks like the back of the OTA will unscrew once it's deforked. But that's getting a bit off-topic for the classifieds.
  7. Thank you John, that helps a lot. I was wondering if brake or gear cable would do the job. I'll get the cable cutters out tomorrow.
  8. Looking for a flexifocus for my ETX-105. Thanks, Douglas
  9. Down here in the southern Alentejo, Portugal at more or less 37 degrees compared to southern UK 51 degrees North, Sirius is way up high right now, and sparkling like crazy anyway. I love the interaction with the atmosphere, with or without a telescope, but most of all through a telescope way off focus, like a plasma ball, so beautiful!
  10. I can't stand the suspense! How come it's still for sale? I just want to look after this lovely little scope but I'm not so often in London. I'll send you a PM in a bit with some ideas how I could get hold of it. At least then I can rest easy one way or another...
  11. Hi, Looking for a vixen (or other) 36.4mm to 1.25 inch adaptor please - to fit to a Prinz 660 drawtube. Thanks, Douglas
  12. So, if anyone one day needs to know... I'm pretty sure it's actually a B50K 12mm radio potentiometer. About a dollar including post from Aliexpress. Will only know for sure if it fits when it arrives by China Post in a month or so.
  13. Hi, Does anyone know where I can find a suitable potentiometer to replace the brightness control on a GP-DX polar axis illuminator? It's an 850k ohm pot according to the text printed on it - I guess logarithmic - but it needs to be the same size as the original to fit on the PCB and I just can't find one... If someone can tell me what this style is called it should be easy, but they come in a bewildering range of sizes and forms! It needs replacing as a previous owner of the mount left a leaky set of batteries in it for too long. Thanks in advance
  14. Hey welcome Eduardo! I'm also in Portugal - near Odemira, Alentejo. Not into astrophotography though, purely visual. So far I didn't find many amateur astronomers around here. Might help if I spoke a bit better Portuguese! Anyway, welcome to the forum.
  15. Only have a 15mm. And I'm keeping it! But 40 pounds sounds quite fine. Will pm you tomorrow morning for payment details if that's okay?
  16. PM'd you. I'd like this eyepiece please. Douglas
  17. Looking for Bob's Knobs for a C8 (standard 6/32 for Fastar compatible C8 with silver phillips factory screws) 29 dollars seems a bit much for 3 screws, and so does 23 pounds. On the other hands, they would make life so much easier... Anyone have an spare set hanging around, before I checkout?
  18. Looking for a Telrad and/or 9x50 RACI finder for my C8.
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