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Geoff Lister

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About Geoff Lister

  • Rank
    Proto Star

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  • Gender
  • Interests
    Railways (full-size and model), radio-controlled model boats, and astronomy
  • Location
    North Somerset, UK
  1. I too have failed to get my Virtuoso mount to go into EQ mode, using the "5" button power-up. However, I made a crude wooden wedge for my 51.4 degree latitude and changed the mount's location latitude to 90 degrees (pretending to be at the North Pole). This gave me tracking movement in the azimuth axis only, so effectively an EQ mount. The mount works well in Az/Alt mode with the Az/Alt V3 Synscan handset "borrowed" from my Skyliner 250PX. Geoff
  2. My 10" Skywatcher Skyliner 250PX truss-tube Dobsonian will definitely not fit in my Mazda MX5 2-seater; all of my other systems will. I bought the Skyliner before I retired, and am glad that I did not go any larger, as I can envisage a time when I will not be able to carry the base and optical tube, the 10 yards (through a limited-width doorway, and down a small step) from my garage to my patio. Geoff
  3. Me too. Having realised that my Astromaster 130EQ-MD was a pain to set up and use, I went for the Skymax 127 GoTo with Synscan handset. This was a vast improvement; and, shortly afterwards, I bought a second one to take to my holiday home in France. The 127mm Mak works well for planets (including Uranus and, just about, Neptune - they look like stars, but with a bit more "body", and definitely need a tracking/GoTo mount to find them, and hold the view steady whilst you change eyepieces). This is my grab-and-go setup Works well for me too. Geoff
  4. There is a nice site with PDFs for printing, and cutting details, at http://www.deepskywatch.com/Articles/make-bahtinov-mask.html Wikipedia has a description of the mask's operation, and a link to "Pavel Bahtinov", but if you follow that link it brings up an "empty" page. Clearly, honours are overdue.
  5. The image in mine remains rock steady as I rotate the focuser. Geoff
  6. With my GPCAM & x0.5 focal reducer, I keep the 90 degree star diagonal, remove the eyepiece, insert the camera, and adjust the focus. Geoff
  7. I bought the Skyliner 250PX, with the Synscan GoTo, after several years of using the Skymax 127mm Mak, again with Synscan. I wanted the features that I enjoyed, but with the possibility of seeing fainter DSOs, and the outer planets. The Skymax is on a tripod, so there are times where it gives me visibility of lower altitude targets, obscured from the Skyliner's Dob. base, by adjacent fences and trees. The Skymax is also slightly quicker to set up, so I tend to use it for shorter sessions. However, if I expect to have a longer session, the (roughly) 4x light capture of the Skyliner, makes it worth while. Initially, I found the Synscan alignment process often suggested second stars that were behind buildings, fences or trees; when viewed from my normal observing position. I spent a few hours with the PC program "Stellarium" and produced a table of 14 of the brightest stars, and for dusk in the middle of each month of the year, noted the rough azimuth and altitude of 3, 4, or 5 of these stars, giving good azimuth and altitude separation, so that the Synscan software could remove most of the alignment errors. I added a bubble level to the base, and use a small wedge under one of the feet to get the base level before I power up. This is not strictly required, but I have found it makes the auto-slew to the second star more accurate, and improves long-duration tracking. When I bought my Skymax, there was a special discount, from OVL (the Skywatcher main importer), for a purchase of a cased set of Celestron Plossl eyepieces and coloured filters. I tend to use these also with the 250PX, although the 8mm and 6mm eyepieces have very short eye relief, so are difficult to use; so I tend to use the 13mm Plossl and a x2 Barlow instead. The 8-24mm zoom (sold under various brand names including Celestron and Skywatcher) is a cost-effective way of adding a range of eyepieces. My Baader one is much more expensive - possibly a later purchase when funds permit. For most targets, I start with the 32mm Plossl, then the zoom to find the best clarity/magnification setting, and then a fixed eyepiece close to the optimum for the seeing conditions. Geoff
  8. I have found that my 32mm, 1.25", Plossl EP is fine for most wide-angle views with my Skyliner 250PX 10" truss-tube Dob. I have a 56mm, 2", Plossl which I use very, very, rarely. I am a big fan of the Synscan GoTo. I have been an OAP for a few years, and I would not want to lug anything much heavier from my garage to patio; about 7 metres through a doorway and down a step. Geoff
  9. With mine, the only way that I have found is to slacken the motor's little thumb screw that links the drive onto the flat of the RA axis manual driveshaft. The setup is not "user friendly"! Geoff
  10. A Google of "RS12 pinout" and "RS232" should give you a good idea of pin locations within the connector bodies, particularly to identify "Pin 1" on the RJ12.
  11. Having spent some of my working life designing telecomms equipment, I realise that the Registered Jack "RJ" connector series is a complete minefield. In theory, it should only be used, as defined by Bell Systems, but in the real world, it is used to define connector body size and the number of connector pins fitted in that body. From my understanding, and a quick check on the web, "RJ11" is usually used for 6P4C, and "RJ12" is the same plastic body but 6P6C. The "RS232" (another data standard, but modified, often heavily in terms of voltage range and circuit impedance, by the computer industry) cable supplied with my Skymax and Skyliner Synscan V3 handsets, has an "RJ12" 6P6C connector, and a 3-way cable [ RED - pin2, BLACK - pin3, WHITE - pin5], terminated by a moulded 9-way "D" female connector with connections:- RJ12 9-way D 2 - 2 3 - 5 5 - 3 Geoff
  12. My (limited) experience is unchanged; they both produce good products. Concerning firmware updates; I have not needed to update any of the firmware in any of my systems. I use the "If it isn't broke - don't fix it" philosophy. Most PC/tablet/phone software requires regular updates, often to correct security weaknesses or to add new features. A mature GoTo is stand-alone, so no security problems; and the night-sky object positioning calculations should be good for considerably longer than the useful lifetime of the mount/handset hardware. As mentioned in other threads; for visual astronomy, the optical tube is most important, usually with an Az/Alt mount; for astrophotography, the mount is more important, usually an EQ mount, and usually more costly to get "decent" results. Geoff
  13. A small dab of cyanoacrylate "Super Glue" may do the job if the proper thread-lock is not easily available. Geoff
  14. A few years ago I had similar problems with my 250PX. The fault was a poorly seated ribbon cable connector on the underside of the azimuth control printed circuit board. It was very difficult to spot - I had to remove the board's mounting screws to see the underside. The ribbon cables passed through ferrite rings - probably a post-design modification to pass international EMC tests - and this extra detour made some of the cable runs very tight. Probably the wise option. Geoff
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