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Astrokev

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Everything posted by Astrokev

  1. Hi I'm hearing good things about APT and am considering giving it a try. I have a Nikon D300 which I believe is supported, but I've seen on the APT site that it requires a serial cable to connect the DSLR to the PC. But, it also suggests that the serial cable is not commercially available, with some instructions to make one. I'm a bit surprised and confused by this. Does anyone else use a Nikon (ideally a D300!) and please could you advise what cabling I may need, where I can get this, and how it all connects together? Many thanks
  2. Looking really good Shane. Good luck with the rest of the build kev
  3. Thanks Michael and sorry for late reply. Yes it was reporting a 78 min error! No idea why it was so bad. Any ways, I’ve re done the PA using SharpCap and my guide camera and it’s now just about spot on. I’ve also increased my guiderate in EQMOD to 0.4 and my calibration is now fine. This hasn’t improved my guiding (still achieving between 1 and 1.5 arcsecs, so I need to look elsewhere. Balance is the first thing on the list. Even though I can’t get under 1 a-s, star shapes are perfectly round and not large, but sub a-s guiding may make the stars smaller.
  4. Thanks Paul and Craney. Good polar alignment is obviously a good thing, but could poor PA be a cause of the poor PHD calibration, or is it more likely to be caused by backlash? If it's backlash, how can I remove this before doing the calibration? I tried using the Manual Guide buttons, but couldn't tell if the mount was moving. The image in the camera image screen is too small a scale to show any movement (although I've seen a YouTube video which clearly showed this movement - it looked like the image screen was zoomed in as the green box around the star was quite large. Anyone know how to zoom in on this image to more easily see movement using Manual Guide?)
  5. Thanks Paul. That needs SharpCap Pro I think? To use Guide assistant, isn't this done after calibration? It's the calibration that I want to improve, and then go from there.
  6. Hi All I'm trying to better understand how to improve PHD guiding, and am having a few calibration problems. Can anyone please offer some guidance? I have an NEQ6 mount and am using an Altair 10 x 60 RACI finder with ASI 120MM mini to guide. Following the calibration instructions in PHD I've selected a calibration star near Dec 0 and just east of the meridian, using Auto-star selection. The Review calibration graph is attached. The West and North lines at not quite at 90° and the return East and South lines are not superimposed over the West and North lines. My mount was polar aligned using the polar scope and I think is OK. That said, PHD guide assistant suggests my alignment may be nearly a degree off, which is huge and I'm not sure is correct. Guiding after completion of calibration was all over the place, giving a Tot RMS error of > 3-4" So, please can anyone suggest what may be causing the poor calibration chart? Backlash may be part of the cause - I tried to reduce this using the PHD Manual Guide buttons, but this doesn't seem to have made much difference. Any suggestions would be hugely appreciated
  7. Mmm, that's a thought....
  8. Yep, sounds unlikely now I think about it! Not a major problem in the grand scheme of things. I can always try and pick up a used short FL scope. An achromat should be OK due to the narrow band I'll be trying to image, so shoulen't be too costly.
  9. I do plan to do imaging aswell. Maybe I should've posted in the imaging forum instead / aswell Doing the maths, I guess 2000mm FL is pushing it a bit for full disk imaging.
  10. Hi All Just playing with ideas to inform a decision - Has anyone used the Quark with a SkyWatcher Esprit 100 ? The scope is a 100mm f5.5 APO triplet. With the inbuilt Quark x4.2 magnifier, I'm wondering whether I'll be able to achieve full disk? From what I've been able to find, this could be a struggle? Also, I believe I'll need a UV/IR cut on the diagonal nosepiece due to the size of the objective. Any thoughts, experience, suggestions regarding this combo would be much appreciated. Thanks
  11. Excellent job. Looks really smart
  12. I imagine you'll find something suitable in your pile of old broom handles waiting to be re-purposed in the back of your workshop
  13. A while since I posted on my thread, so this is to let you know I'm still here . Eventually started work on the step and path. Not much to show yet, but think I've figured out what I want it to look like and have most of the materials. Just starting to prep some sort of foundation cement layer. Much easier laying bricks when what you're laying them on is level!
  14. Yes that looks very neat!
  15. My tiles expanded hugely when I was doing some solar earlier this week. It was like walking around on a bouncy castle. I need to measure the expansion and decide how much to trim.
  16. Like I said, I'm sure it's fine, but the weight of concrete is not the most important factor IMO, but the depth and width (and 70kg is not actually that great by "traditional" pier block dimensions). My pier block is a 75cm cube by comparison, with rebar going through the block into the surrounding ground, but I accept this may be a bit of overkill! Interested in your security solution. For interest, how strong are the sides of the blocks, as they look quite narrow? Would it be possible to crack the sides with a single blow with a lump hammer I wonder? Probably unlikely to occur of course, but there has to be a risk of leaving the EQ6 permanently mounted. If someone has a mind to steal your kit, they'll probably find a way. A friend of mine takes his mount off the pier at the end of every session, which obviously eliminates the risk. Looks very neat and tidy though and I'm sure will work fine. The new EQ6 mount is a nice design. Are you not tempted by imaging?
  17. Yes the weight shouldn’t be a problem. My only small concern is not with the weight, but the small risk of you accidentally leaning or falling against the pier. The height of the pier/ mount will create significant leverage and the block may not be massive enough to resist the torque forces acting on it, causing the block to loosen or the pier to move slightly. If you’re only doing visual this may not be a risk worth worrying about, but something to be aware of. So long as you don’t bash into the pier you’ll probably be ok!
  18. Re: the discussion a short while ago about floor tiles expanding, or not.... I said my tiles are laying completely flat and show no obvious sign of expanding. This statement clearly annoyed the observatory gods, as today I did some solar with a good friend. Once in the sunshine, the floor tiles buckled up like a bucking bronco. Hmm, me thinks I’m going to need to trim some off the edges!
  19. Looking really good James. It feels good to get the flooring down doesn't it! Looks like you've done a great job. The post support feet sound a great idea. I've seen these in a new housing estate near to where I live, supporting the posts used to construct front porchways. I wish I'd used them for my posts now, mine being embedded in concrete. I've resorted to painting the bottom of my posts with about half a gallon of creocote, so hopefully I shouldn't have anything too much to worry about regarding risk of decay!
  20. Good luck with that. Will you be pouring the concrete in direct contact with the ground in the hole? I would personally suggest this as the best approach. Some folks put shuttering around the edges of the hole and then remove this once the concrete has gone off and backfill with a vibration reducing material. I personally worry about this method unless the concrete block is very substantial. For your build I don't think the block is massive enough for this approach and may risk movement of the pier.
  21. What size hole are you planning to use ?
  22. Wow, only just seen this thread. Great build and those domes look fabulous. Good luck with the rest of the project. Looking forward to seeing the finished article!
  23. Good luck with the build David. You need to get those scopes up and running! kev
  24. Just noticed that my build thread has hit 40,000 views. That’s pretty crazy . I hope some have found it an interesting build to follow so far. But I’m not quite finished yet. There’s a current lull in activity at the moment while I focus on other needy things, but hoping to give it the final push in the near future. I’ve got the materials to start doing some exterior tidying up and path laying, and hope soon to be installing the electrics. So, if you can stand the suspense - please keep watching this space, and thanks for your interest so far .
  25. For what it’s worth, my rubber tiles are not stuck down, and they lay perfectly flat with no edges riding up to create trip hazards. I’ve not experienced thermal expansion of the tiles so cannot comment on this from experience but, if they do expand as many claim, it strikes me that sticking tiles down may inhibit tile movement to accommodate the expansion, which may cause the edges to buckle up slightly. This may actually exacerbate the risk/ problem.
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