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About Merlin66

  • Rank
    Bright Giant
  • Birthday December 9

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  • Gender
  • Interests
    Spectroscopy, Solar observing,- and my wife!
  • Location
    St Leonards, Vic, Australia
  1. LS50THA + LS50C Double Stack

    Sounds pretty normal. The tilt tuning works by moving the central wavelength from the red side of Ha towards the blue.... Just check the initial etalon in the LS50 is tuned to give the brightest clear image you can get, and only tilt the front etalon to a minimum to move annoying reflections from the disk.
  2. Yes, all front double stack etalons, both Coronado and Lunt are tilt tuned.
  3. The Vegemite lids act as a semi-remote tuning of the double stack from the eyepiece. works very well!!
  4. Stacking Solar scopes

    The original OP.. The wedge is perfect for white light viewing - sunspots, granulation and brighter surface faculae - you need the expensive narrow band Ha filters to be able to see the filaments, prominences etc. A double stacked (or Quark) configuration allows finer detail to be seen on the surface (improves contrast). Hope this helps.
  5. Here's my SM60 external etalons double stacked on the ED80......
  6. Stacking Solar scopes

    Brian, Interesting set-up.... Yes, theoretically the triple stack would further reduce the bandwidth - SS 0.7A, DS 0.5A, TS 0.35A and reduce the transmission to 0.8 x 0.8 x0.8 = 50% Removing the ERF is of limited value - the transmission of the ERF is around 90%. Tuning a triple stack will call for some rigor. Each etalon must be tuned to almost exactly the same CWL......
  7. Stacking Solar scopes

    I used a Coronado 60 double stack set-up for many years. No issue no drama. To answer your original question Re double stacking. Each of the etalon filters are "tuned" to the H alpha central wavelength. The shape of the transmission curve albeit very narrow, approximates to a Gaussian bell curve. When the two bell curves are superimposed on each other, the total transmission is reduced by around 50% and the final transmission bandwidth by approx 40%. If two, say 1.0A filters, are stacked, you get around a 0.6A result.
  8. Polar aligning an ALT AZ EQ6

    Goran, Bang per buck the SW mounts work well. I have and use the HEQ5pro (solar) and the NEQ6pro (pier mounted - C11 plus spectroscope). I can achieve subs >10min easily and successfully hold a target star image on a 20 micron slit plate. Works well for me.
  9. 12v supply to SW HEQ5 pro mount

    I use a 180A TURNIGY Power meter (https://www.ebay.com.au/i/152348206804?chn=ps&dispItem=1) to monitor the current, and voltage at my pier. I also have a power convertor (similar to the one used on the mount) which gives 6.5v for the powered USB hub.
  10. Off axis guider?

    Hmmm Finding an OAG body narrow enough to fit the newtonian may be more of an issue than the guide camera. I use the Lodestar for spectroscope guiding (similar to an on axis OAG) on the C11 at f10, but have had similar success with the QHY5IIL. My electronic finder, a 60mm finder using the DMK51 works very well.....
  11. Budget Observatory under £250

    On the TSO I used a turnbuckle and eye on each side of the roof. Worked well.
  12. Budget Observatory under £250

    TSO I in the UK was assembled on rented property. It was fixed to the patio tiles with just four screws - the owner didn't want any visible damage.... I didn't worry too much about the rising damp or leaks under the walls...... TSO II in Belgium was again in rented property and the only location was a gravel path near a fish pond. I used long tent pegs to hold it down and this time added a thick plastic sheet which cover the whole base area and turned up (about 75mm) onto the inner walls. Later I added those clip together foam tiles - which worked 100% TSO III back in Oz was the first opportunity to actual cast a concrete base. I used a wide foam sealant strip around the base of the walls and some self adhesive aluminium flashing to obtain a pretty good seal - reused the the foam tiles. No issues, no drama. When I moved to St Leonards I sold the observatory and it's now reconstructed north of Melbourne as TSO IV............. (My current observatory is a modified substantial wooden wookshop - I removed half the roof and turned it into a ROR and retained the other half of the shed as a workshop.)
  13. horse shoe mount

    Hmmm You can design the tracking on micro pulses say to give < 1 arc sec per pulse then use a smaller gear ratio (ie faster) to get a better GOTO rate. x 3 siderial GOTO is too slow - that's more like a guider rate - look around the x10+ sidereal for GOTO. Just my 2c
  14. In my experience, you won't use a Barlow for visual in a SCT. Change the eyepiece.... I use my Genesis diagonal occasionally in the C11 with the SCT to 2" fitting, but I find the Meade 2" SCT diagonal to be the most used.
  15. I think the CFA = Colour filter Array, aka Bayer matrix.