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I am selling a JMI focus motor for Meade SCT's.
It has a replacement controller as the original was lost many years ago. Works fine on a LX200.
Asking £40 for complete unit and controller plus £5 if you need it posted.
***************** SOLD ******************
Took my Celestron AVX Mount out this afternoon to familiarize my self with it in the daylight. Wasn’t sure if or how it would work, since it’s my first goto Mount. I got it setup per the directions and attached the SkySync GPS. It locked on my location very quickly so I did the Quick Align option just as a test. The polar scope was oriented north, and I used Sky Safari to locate stars I couldn’t see cause it was daytime. My first choice was Sirius and it slewed right around to what should be the general vicinity! I then chose Venus in the West and off it went! I hit home and it went back to the original setup position. I can’t wait to take it out tomorrow night and really put it through it’s paces! This is totally most excellent!
lets imagine I wasn't to see a nice DSO about 15' size and I think it should look good nicely framed with a 1 deg field of view in the EP..
Which would give the better (or higher probability of seeing anything at all ) view from a semi urban light polluted home site (e.g Bortle 6)?
a) an 100mm f/6 refractor (fl 600mm) and a 10mm EP (60 deg afov, gain 60x = fov pf 1 deg)
(and exit pupil of 100mm / 60 = 1.6mm)
b) a 200mm SCT with focal reducer to give f/6 (fl 1200mm) and a 20mm EP (60 deg afov, gain 60x = fov of 1 deg)
(and exit pupil of 200 / 60 = 3.3mm)
My gut feeling is that the SCT should give a better view just based upon its 2xaperture - but Im not sure I understand fully the maths why.
Is the larger exit pupil going to result in a better / brighter / more successful view?
Or will the view be 'roughly' the same ?
Or have I got it all wrong.....
I am only a few weeks into astronomy and started off with a Celestron 9.25" Evo on the standard AZ mount. I guess with hindsight this wasn't the best place to start and also with hindsight I would have done better to have bought a GEM mount. Anyway, lesson learned and at 71 years old I have to speed up the learning process compared to younger enthusiasts I have 2 issues. 1/ Its a pain dragging the scope out into the garden and setting it up every time I think the fickled weather might be obliging. 2/ I now know that the mount I have is useless for long exposures and a wedge is fiddly to get polar aligned.
My question is, though I gather wedges are a PITA to setup etc is if I was to build or buy a pier for the backyard and use my existing mount + a wedge is this a reasonable way to go? Though it's fiddly to set the thing up once set I could leave the mount, wedge, etc covered up and would just need to drop the OTA on when I wanted to use it. Is this reasonable or am I missing something fundamental down near the bottom end of my learning curve
Any advice much appreciated and don't feel you have to spare my feelings