Merlin66

I use three ED80 scopes and a Genesis..... I feel uncomfortable (!!) after being so impressed with the Petzval design Genesis for so many years to admit that the performance of the ED80 is very (very) good. I would recommend the ED80 scopes to any amateur. Bang per buck they can’t be beat.

Here some photos of my set-ups. 6mm MXL belt and 30 tooth pulley on the motor.

+1 from me! I use it most days for solar imaging.... It did at one stage have the dual CometSeeker and ED80 mounted. No issues no drama.

Back to basics.... Amateur Telescope Making, Volume 2, p623-647 The definition of the RTF = Richest-Field Telescope (note - not just a rich field telescope) to quote: "....every aperture could be made "a" RFT of that aperture, for a given observer and that there was one of all these which, in connection with the curve of star density against magnitude of stars, was uniquely "the" RFT for the observer, in respect to the maximum countable number of stars per apparent square degree" Note there's no real mention of field of view, just the maximum stars per square degree. Based on the subsequent tables (p624/5) a "real" RTF of 10" aperture at x33.9 would give a FOV approx 1.5 degree and show 306,000 stars per square degree down to 14 mag. These figures were based on the available eyepieces at the time, AFOV 40 degree, and a rich galactic star field being observed. It is also based on a dark adapted eye accepting a maximum of 7.5mm exit pupil. EDIT: The Borg 67mm is close to 2.5" aperture.... The ATM table (p624) gives: Limiting magnitude 11 Magnification x8.5 Total stars per sq. degree 25,400

OK, on my HEQ5 mount the two small thumbscrews on the Dec circle are M2. The larger screw holding the RA circle is an M4. HTH https://www.amazon.com/FidgetFidget-Thumb-Screws-Screw-Stainless/dp/B07N41CC67#HLCXComparisonWidget_feature_div If you can't source replacement thumbscrews, try a M2 stainless socket head screw

Mog3768, can you upload an image of the focuser setup you tried? I successfully use the SW motor with belt drive on all my solar scopes.

I believe they are M2 screws. I’ll double check and confirm.

I think the transmission is a poor comparison to a proper V photometric filter.

Hhmmm The quoted bandwidth (FWHM) for the Baader K-Line filter is 80A ( https://www.baader-planetarium.com/en/baader-k-line-filter-1¼"-(double-stacked).html) whereas the Lunt CaK is said to be <2.4A bandwidth.

I used a 50mm angle ring and 100mm rollers. Worked very well no real issues. You can see them in the background supporting a Octodome......

Looks the the same as the GSO 10:1 focuser I use on my ST80. works very well for me.

I don't have to recalibrate at each session or when changing target. The ST-4 connection just works for me. Not sure what bad experience you may have had with ST-4 connections.........

Forget the Sun as a reference point. It's just another astronomical body which has it's RA/ Dec defined by the Epoch used for the coordinate grid system.

I think your over thinking the whole issue of what RA as a coordinate system is all about. You're familiar with Long and Lat position to define a location on the Earth's surface. In the sky we have a slight problem..... The stars and galaxies don't move much over the years relative to each other...but...the coordinate grid we "overlay" on the sky, unlike the fixed Long and Lat on Earth does move due to precession. To "agree" on a location of a star/ galaxy using a coordinate system we must therefore all agree on a "base" for the timing and hence positioning of the RA grid on the sky. It's usual to use either J2000 or Jnow to "reset" the coordinate system. Depending on your planetarium program and drive interface. It doesn't matter which one you use, as long as you're consistent. A star's RA is the sidereal time when it crosses the meridian.

The attached sketch shows the cable arrangement. Hope that helps.

OK. I find for solar imaging the 10:1 works well for me - I now have similar set-up on all my scopes.

When using the ST-4 connection, If you enter your mount details in the PHD box "Aux Mount" it will communicate the mount position to PHD2. This is the set-up I successfully use with my C11 (for spectroscopy) on the HEQ6 mount. Works well for me.

Instead of two winches, I use a continuous loop and one "pull cord" on my run-off roof. One side attached to the rear of the roof and the other to the front of the roof, two pulleys at the rear wall, one for each cable run and an "loop" which allows you to add a winch if needed. I can provide a diagram if needed. I've successfully used this arrangement on various observatories since the early '80's.

John, Great set-up. I use the same arrangement but use the belt drive on the 10:1 knob for even finer focus control.

Well done mate!

John, The flats should be taken with exactly the same optical arrangement you use for normal imaging. Don’t change focus or anything else. The exposure should be the only variable. The doughnuts you see are supposed to be there. They are the “shadows” caused by dust in the optical train and exactly what the flat is designed to remove.

Yeah, all the eyepiece projection units I’ve seen are really for use with the “traditional “ smaller body eyepieces, like the TV plossls.

Surplus Shed always has various eyepiece components available.

When we moved house I “inherited “ a fully finished 6 x 3 mtr Shed. This has a substantial concrete floor. I split the roof and made a 3 x 3 mtr observatory for the C11/ NEQ6PRO. The pier was extra height to give a view over the 2.7mtr walls. This is bolted to the floor slab with 4 x 18mm expanding bolts. It’s been in operation now for over six years. It works well for me, no issues.

The AR 2797/ AR2798 and AR 2799 are pretty obvious, but there's another un-named area just coming into view in the north east.... The conditions were so bad, I just tried some CaK images. Not the best but at least record the recent activity. Enjoy!