Posts Made By: Louis Busby

I'm interested in turning either my Takahashi FS60C or FS78 into an H-Alpha solar scope. Can anyone offer suggestions regarding the best combination of readily available adapters, BF/ERF and any other requirements? I would like to use it for visual and webcam photography.

Last night was the first opportunity to run my new Tak Mewlon 250 through its paces. I set the scope up well before sunset so I could catch any peculiarities associated with the 250 setup. The weather promised to be okay, although not ideal with a forecast of severe clear and good transparency especially between 10PM and midnight. Unfortunately that was not to be since a high thin layer grew thicker throughout the night. By 3AM only Vega and Arcturus were visible.

The Mewlon 250 was a little awkward to set up, much different than my Tak TOA130 refractor. The Mewlon was a pound or two heavier than the TOA and because it is short and fat and very heavy at the mirror end one had to be careful that the mount was locked down to prevent unexpected movement. The Mewlon came with its native Tak 7x50 finder scope and the previous owner had installed provisions for a StellarVue F50 which also came with the scope. The Tak finder is a jewel in itself presenting an illuminated crosshair and a wide FOV. The Tak finder is permanently mount to the Mewlon OTA and has no adjustments. Remarkably, its alignment with the Mewlon was dead on.

After polar aligning my Losmandy EQM I dialed in a bright star to get a feel for what the Mewlon would present and to check finder alignment. Now, before I go any further, keep in mind that my references for performance come from the Tak TOA130 (5.1”) refractor and a previously owned Meade 10” SCT. The first bright star was Regulus in Leo. Saturn was very near Regulus and would be my first serious target, so it was just a few degrees away. The first thing I noticed was how crisp Regulus was in the Mewlon. The star was a “in your face” bright pinpoint very similar to what the TOA130 would present in the same circumstance. No SCT fuzzy ball of light reminiscent of the Meade. I checked collimation and it was a little off from true, but not by much. More about collimation later.

Next I slewed the Mewlon over to Saturn. Now planets are where this scope really shows its stuff. Because of the Mewlon’s 3000mm focal length you don’t have to dip into your collection of high power EPs to see wonderful detail on the ringed giant. I tried a 20mm Nagler which yielded a very nice 150x magnification. Because of conditions, detail was lost with anything greater from 17mm down. It was on Saturn that I really noticed collimation error. As I defocused, I notice a slight double image of Saturn moving to one side of Saturn prime. It seemed to be just off and because Saturn was in such a good position for me I decided to take a couple of ToUcam shots just to see what could be rendered. I was very surprized at the results from a stack of 1500 frames even thoguh conditions were poor, but seeing was decent. I also wanted to check out the moon, but it was well below and behind some trees so it would be a while before it was in plain view.

I decided to kill time by attempting to better collimate the Mewlon. I did it visually, but since I was unfamiliar with the collimation process with this scope I toiled with it a bit before I was finally able to improve collimation over its original settings. When the moon finally rose above the trees the sky was starting to degrade and the moon became a diffuse brilliant (98%) blazing ball of light that reduced the detail that one is familiar with. Not a very good target at all. Working on collimation again and over a period of 3 hours I was able to fine tune collimation to a remarkable degree. Cygnus was just clearing the trees and the moon was past the meridian so I decided to explore a few objects in that constellation. I looked at Vega and the Double-Double in Lyra. The DD was easily resolved with a 20mm EP. Next were M39 and Albireo. Albireo was stunning and the Mewlon truly presented it with refractor like performance. Transparency was below average so trying to view any deep space objects would have proved futile. I was however tempted to pull in M27 and although conditions were poor I could easy make out the dumbbell shape. The remarkable thing was that in low power EPs the nebula was huge. The same applied to M57, the Ring Nebula. M57 was clearly distinct and was presented as a well resolved ring in the middle of my FOV using a 26mm Nagle (115x).

I spent the remainder of the night cruising star fields with the Nagler 31mm. When considering my past experiences with the TOA130 refractor and the Meade 10” SCT, I easily forgot I was using a mirrored telescope. The Dall-Kirkham cassegrain design presented crisp and contrasty views of the night sky. I can’t wait to get this baby to a really dark site with good weather conditions. I can easily see the Mewlon replacing the TOA130 as my favorite scope to use.

Can someone explain how the tube counterweight attaches to the Mewlon 250 tube. I don't have any CWTs yet, but will require them before I start attaching a camera to the Mewlon. I heard the weights are magnetic. Do they just stick to the tube or is there something else I need for these/

Also, what is the correct procedure for collimating the Mewlon 250? I don't have any instructions. Which screws are for collimating? There are two sets of three. I assume that one set is to lock in collimation. I want to understand the method and mechanics of collimating this scope.

It's been awhile since SBIG introduced the ST4000XCM. Yet, I've not seen any user reports or any images from this camera. Can anyone share their experiences with the ST4000XCM and possibly post some images or provide a link to some images from this camera.

Can anyone tell me which adapters I will need to attach a STL11000 to a Mewlon 250, TOA130s, FS78 and FS60c? I have an STL on the way and would like to get the adapters before it arrives.

Canon 20D on a Takahashi FS60C.

I'm currently wrestling with collimating my Mewlon 250. I've spoken with Fred at TNR and he has walked me through the process (more or less), but there are still some things I don't understand. For instance, the push/pull sets used for adjusting secondary position -- What is the effect of turning the push screw anti-clockwise? Does it simply pull away from the secondary? In which case the pull screw would be turned clockwise to bring the secondary back to contact with the push screw. Is that right? And what is the effect of turning the pull screw anti-clockwise?

Fred, also mentioned that before any adjustment of the push/pull sets is done, you must first ensure the a third set of screws are snugged. This third set are supposed to be in position at 11-2-6 oclock positions on the secondary cell perpendicular to the push/pull sets. Are these screws familiar to any 250 owners? I can't seem to locate them. Fred says that they are 1.25mm hexscrews. The push/pulls are .9mm. Is Fred referring to the spidervane adjustments? I dunno, I'm perplexed.

Does anyone know of a link or might have a detailed description of collimating the 250s? Hopefully, with pictures? Fred says he's been meaning to sit down a write some up, but has yet to do so.

I'm looking for ideas/solutions for mounting a FS78 and TGM-2 side by side with either a Mewlon 250 or TOA130 on a Losmandy G-11.

Help appreciated.

or...Observatus,astronomicus,maximus

Here's my usual setup up at Milam Gap, Skyline Drive, NVA

Here's a close up of Copernicus taken with my Takahashi Mewlon 250 and a ToUcam 840. 50 best frames of 1200 in poor seeing.

Diameter: 93km
Depth: 3.8km
Central peaks rise some 4oom from the floor of the crater