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Peter Drew

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Everything posted by Peter Drew

  1. Bedfordshire was a hotspot for astronomical manufacturing during that era. As well as my own company Bedford Astronomical supplies, there was Astrosystems of which I was a founding director along with Rob Miller and David Hinds, Astronomical Equipment (AE), James Muirden and latterly Superscopes. Also of note, the legendary Horace Dall and astronomical electronics specialists Astrotech. I did know Phil, in fact he did credit me with being his inspiration to form his business, the quality of his work is evident in the photos. I left Bedford to move up North to found the Astronomy Centre which pre-dated the Bedford AS but I was a member of Luton AS and its Chaiman at one point. Good to know that Phil is still active in Astronomy. πŸ™‚
  2. Yes. Wrapped in a duvet contained in a suitcase. πŸ™‚
  3. As the originator of the "Todmorden" pier I'm always pleased to see another one take shape. Also pleased to see the mount bolted or fixed through the top of the block rather than a rat's cage. πŸ™‚
  4. Other than no grease I doubt whether grease will cause binding of the worm gear. Assuming the mount in question is your CG4 and if it is similar to the Vixen Super Polaris mount, the the RA bearings might well be plain metal to metal contact. Too tight a gear mesh could cause excess pressure between the mating surfaces and produce binding. Cold will also make the axis harder to turn. πŸ™‚
  5. I also exclusively use binoviewers for Ha observing, however for small entry level Ha telescopes with double stacking, the light loss through a binoviewer might render the image rather dull unless a full head cover is used to keep stray light away from the eyepieces. πŸ™‚
  6. I took a Celestron 8se to and back from Tenerife via Easyjet with no problem, all items in hold luggage. πŸ™‚
  7. Just had the first light with a hybrid Ha system. I've double stacked a Coronado PST with the front mounted etalon from a Lunt LS35. The mod was just a simple component to attach the Lunt unit to the front of the PST. Despite operating at 35mm aperture the images are superb, far better than either telescope in single stack and better than some 60mm single stack versions. As usual, double stacking dims the final image but with a head cover the results are spectacular. I now have an easily portable Ha telescope to complement my fixed 150mm. πŸ™‚
  8. On my 8se I noticed any backlash problem was caused by the shaft holding the brass gears being unsupported at the outer end. Despite the gears meshing accurately, the brass gear unit could be pressured sideways enough to allow flexure of the Dec axis. To remedy this I turned a diameter register on part of the brass gear and made a bracket with two small ballraces spaced radially to form a rolling support under the brass gear. The only downside was having to cut an aperture in the cover to clear the modification. πŸ™‚
  9. It will be the same as usual. Hopefull vendors seated behind rows of amazing but unaffordable equipment whilst attendees with an average age of 65, clutching freebee catalogues, play with the knobs on the focusers. πŸ˜„
  10. As well as being ring fenced by the largest wind turbines available that spoil the seeing we now have to contend with half a dozen arc lights installed by a new owner of a business less than 400 yards away. They seem to be directed at us and are bright enough to cast shadows. A friendly approach to explain the problem it causes our observations/photography has been met by "your problem, not mine, it's my land and I can do what I like". We have now approached the Council and await to see if he's right. ☹️
  11. Given similar quality telescopes, the 114mm reflector should be better for DSO's due to the larger aperture, the 80mm refractor, if a reasonably long focal length, should give tighter star images and better lunar and planetary performance. It all depends on which "better" suits you. πŸ™‚
  12. The Sun can be surprisingly difficult to find in a solar telescope. More so if you've left the objective cap on. πŸ™‚
  13. For balance, I have no guilt at all. For what I use my kit benefits so many that the cost is immaterial. πŸ™‚
  14. I don't think there is much of a debate about it, I believe that it is well known, in practice, that a line on the limit of visibility is reduced to a potion the same length as its width is becomes invisible. Isn't the Cassini Division below the theoretical resolution of some telescopes that can reveal it? πŸ™‚
  15. I wouldn't have thought that the portion at "B" would protrude into the light path of the primary mirror enough to have any significant consequence. Your idea to cut the focus tube enough to leave the original motion stop seems sound. πŸ™‚
  16. I have three ST80's, two as a binoscope and one as a finder on one of my large telescopes. As Stu, and others have found, the accessories tend to limit the performance of the comparatively good objective. Another interesting experiment would be to use the supplied basic accessories on a higher end refractor to see by how much they diminish the performance. πŸ™‚
  17. I could have a look at them for you at the Astronomy Centre. πŸ™‚
  18. For future reference, for small incremental increases in aperture, the most noticeable improvement in performance is the quality (usually luck of the draw) of the critical components. I have had 40mm PST's that outperformed some Lunt 60's. πŸ™‚
  19. Easiest way is using a Herschel wedge for "white light" for sunspots etc, or as Stu says, a Quark for H-alpha. The cheapest conversion is a front mounted solar film filter for white light only. Slippery slope financially! πŸ™‚
  20. There are, however, plenty of small inexpensive entry level refractors that have good optics even though the supplied mounts and accessories are of poor quality. The generic 60mm F11-ish objectives are usually surprisingly good, the ones I used for my binoscope easily supported 120x and were full aperture. πŸ™‚
  21. I strongly suspect that the reduction in effective aperture is to further control aberrations. I have seen many such instances in entry level refractors. Interesting that at least the box recommends use for terrestrial and bright astronomical use, areas where the reduction in image brightness would be least noticeable. πŸ™‚
  22. In retrospect, I thought this may be the case, hence the ? I was aware that certain mediums pass unwanted radiation despite attenuating the brightness. I'm not surprised you know better but one can't be too careful with solar observation. πŸ™‚
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