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almcl

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About almcl

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    Proto Star

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    Telford, Shropshire
  1. I had to replace my QHY5Lii mono when the rear USB connection became intermittent and then failed completely. The very inflexible, heavy, supplied USB cable was probably the main culprit. I replaced it with an ASI 120 mini which seems to be just as sensitive, has a better USB connector/cable and, colour apart, is pretty much identical in appearance to the QHY item. It has proved more durable and has never failed to provide a selection of guide stars when used with an OAG.
  2. While that's quite true, it may still be possible that the ripples on your star trails are in part caused by periodic error. There is almost always more than one component to PE and the periods are often not harmonic with each other. Here's the unguided appearance of my EQ5 (stepper motors rather than SW motors): It's not that regular, but it is largely down to 5 or 6 quite large but independent frequencies superimposing on each other, the largest being the worm period at 300 seconds: The good news is that with guiding, most of this can be smoothed out (it wasn't a night particularly good seeing so some of the short term random movements are still there):
  3. Yes, a piece of aluminium plate off eBay (I think) and a spare Skywatcher small dovetail with some suitable bolts and countersunk set screws. Wasn't too expensive.
  4. Although it is not stated here, the OP isn't guiding, just tracking, so yes, it does look like PE, but PHD2 isn't on the agenda just yet.
  5. You've captured stars down to Magnitude 15, which is pretty good, and it seems quite close to focus as there are diffraction spikes on Phi Per (the brightest star). When stretched there's some nice colour in the stars, as well. Here's a quick stretch to show:
  6. I think that should guide out reasonably well. BTW you have a PM.
  7. Here's how I mount and guide my Canon + 200 mm lens on my EQ5 (ignore the stepper motors - my EQ5 was a manual at the beginning) The finderscope has an ASI 120 mini mono and regularly guides at around 1 arc sec
  8. Not sure if this is relevant but are the guidescope focal length and guide camera pixel size entered correctly? Some have reported finding these changed for no readily identifiable reason. Can you post a guide log with one of these failed calibrations?
  9. If only that were the case! My SW200P has had several cases of dew on the secondary and some of dew on the primary - this seems particularly the case when we have a clearance in the evening after a day of rain. The outside of the OTA is often running with water by the end of an imaging session. The angle of the target doesn't seem to make much difference. I now use a dew shield on the front end which has helped somewhat (it also improves stray light rejection) but on occasions have had to resort to a heat gun on low power to clear the mirrors. This approach carries a bit of a risk so if you discover you need to adopt it, take care!
  10. Not necessarily so. If it's one of Juan Fieros's modifications it will still autofocus because Juan re-shims the sensor to achieve this. (Halfway down the page here: https://www.cheapastrophotography.com)
  11. Can you take an image with your Bahtinov in place and in focus and post it here? A high ISO and sort duration shot will be fine. (If you enable the R+L in the Qlty box in APT you won't have to convert your raw files to jpg). I use the SW coma corrector with its associated 48mm adapter (takes all the guesswork out of getting the correct distance to sensor) on a Canon 700d (admittedly on a SW200P rather than a PDS) and find the Bahtinov works OK so this should be fixable.
  12. You don't need a guide scope to platesolve. Just the main image from your imaging camera and APT can be asked to drive the scope to position of your first night's image. It will do this by solving an image, slewing to where it thinks the target is, taking another image and so on until it judges it is close enough. The tricky bit (for me) is getting the camera at just the same orientation as it was the night before so that the frames line up and don't require cropping once stacked. APT does report 'camera angle' but this isn't always reliable, I find.
  13. Thanks for the warning, hamfisted is my middle name!
  14. I'll certainly have a go at the connections, but wonder if it's actually further downstream than the plug. Perhaps I should look at the circuit board in the mount and check the cables there?
  15. Julian They are a bit massive (7Mb for the debug file), but for the event in the last image above, move requests were small decimals (0.27, 0.16). Suddenly at 21.06.57 the RA move jumps an order of magnitude to 7.7 then in successive move requests it goes to 12, 22, 36, 22 before dropping back to smaller numbers and eventually to small decimals. From this, I don't think EQMOD lost contact with the mount but rather that the mount didn't respond for a while? There are no error messages that I can see so PHD2 seems to think all is well.
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