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Rusted

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Rusted last won the day on November 9 2020

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About Rusted

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    Brown Dwarf

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  • Website URL
    http://fullerscopes.blogspot.dk/

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  • Gender
    Male
  • Interests
    ATM, imaging, solar, Solar system, photography, blogging, cycling, walking, birdwatching, digiscoping, audio, DIY, clocks.
  • Location
    Exiled to sunniest and darkest, rural Denmark!

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  1. Hi, I have collected several parabolic dishes for remote [British] satellite TV reception over the years. Over time the Astra 2 footprint regularly shrank below worthwhile reception here on the Continent. Unperturbed, I regularly increased the size of my [secondhand] "dishes" to achieve modest reception at specific times of the day. I still have 1m offset. Plus 1.8m [GRP] and 2.3m prime focus dishes. The latter a professional quality aluminium dish with reinforcing cage and massive altaz mount. All are no longer required. So could become oversized [Olympic sized] bird baths.
  2. I spent the entire day trying to resolve the multi-spot AR12814 in very soft seeing conditions. I should have had a proper look around much earlier. It was sheer luck I spotted Nigella's infamous Tower prom.
  3. Bagged this before lunch. Loads of cloud today! Weird, patchiness above the limb. Swapped Lunt BF for PST BF for more contrast.
  4. Another morning freezing in the obs. It has just reached 50F/10C. Seeing soft. Thick cloud wandering over.
  5. I bought a 150mm f/10 iStar objective to replace my old [secondhand] Celestron F/8 with internal GPC and sub aperture D-ERF. F/10 directly matches the PST etalon without needing further optics. Though I had to buy a larger Baader D-ERF [160mm.] Just to stop me setting fire to aperture stop rings in the dewshield. Solar imaging, even with PST mods, is not a cheap hobby!
  6. Interesting you should say that. I have used a PST etalon with both of my 6" refractors. The original blocking filter is far better at proms than the Lunt B1200S2 which I bought later. While the Lunt is [usually] far better at surface detail. Seeing permitting of course. The PST BF lets far more light through [than the Lunt] allowing a much lower gain increase for pulling out the proms. The extra gain required by the Lunt spoils the contrast for proms or seriously slows the FPS if the gain is left alone. Peter Drew has repeatedly mentioned that the relatively tiny PST BF is wel
  7. Thanks everybody. The seeing just did not support "serious" imaging. Imppg saved the day again. I was still trying after 6pm but the cloud was battling with the trees for submission. Of course it is clear now that I have packed up and the trees have won the day.
  8. Hi Stu, I just had a look in white light. At least four dark spots in my old Vixen 90mm/f11 with Lunt wedge. The sun has come back out again after loads of cloud but the seeing has gone completely mushy in H-a.
  9. A sunny morning had me back in the observatory. Nothing worked! Flat batteries and Firefox madness. I managed a couple of poor captures through clouds but nothing since.
  10. I saw a complete chain of Starlink satellites crossing the sky one night. Even after sixty years of amateur astronomy it was completely surreal! They too disappeared into the Earth's shadow. It is rare not to see some satellites when you enjoy dark skies. May I recommend a pair of binoculars to allow you to see more? 8x40 is a nice size. Light to hold and carry and can be used to admire the sky, the view, birds and animals. The modest magnification avoids exaggerating any handshake and makes finding stuff much easier. Keep looking up and be safe.
  11. Nice! Ideally, you should weigh both [complete] OTAs and then space them away from the DEC axis. To balance their moments just like a simple see-saw calculation. Mass x distance from the axis. I used a crossbar on either end of the saddle. Then placed the heaviest 180mm OTA closest to the DEC axis. The lighter 150mm was then spaced on the other side of the DEC axis spaced to balance the pair. It worked. With three smaller OTAs you'd weigh all three. Place the heaviest in the middle of your two crossbars. Then add the balanced OTAs. Carefully spaced on either side according t
  12. I should have said more clearly that the balance problem is applied torsion around the DEC axis. Some people add a weight on a stalk at right angles to the saddle and DEC axis. I tried that but ended up calculating the moment of the OTAs around the Dec axis as if it were a simple see-saw.
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