Testing the MAM-020

First tests  -  Testing the GoTo - Deep Sky Imaging

I have set up the MAM-020 again, and again with my William 110 mm Apo. This time inside my telescope hut, so I don't have to remove it at the end of the observing session. I wanted to test the GoTo capabilities and setting it up to test a new CCD camera - but more about that later. Here, a quick report on the GoTo capabilites.

At first, you have to align the mount to the pole star. Manfred built an objective lens into the polar axis, I guess it's about 20 mm in aperture. One can insert a 'Meade astrometric eyepiece' into the lower end of the mount. As mentioned before, when its inserted all the way I couldn't see anything... But when I pulled it out about 2 mm, I saw a few stars, down to about 7 mag. The eyepiece has a complicated reticle (see image below) which can be illuminated, very useful even under my bright skies. I find the way of the polar alignment very ingenious - as described in the operating instructions of the MAM-020, one first has to align the stars alpha and delta Ursa Minoris as shown in 'Bild 2'. This meant some playing around with both the mounts position and the rotation of the eyepiece. I realized that I can turn the complete telescope to find the proper rotational orientation. I had the telescope mounted for the process - the recommendation is to do the polar-alignment before mounting the telescope, this will make it easier as one can turn the polar axis without bumping the scope into anything. I first rotated the eyepiece by loosening the retaining screw, but then of course the eyepiece will slip out of focus due to gravity - so the recommendation makes a lot of sense... But I managed anyway, it just took a little bit longer.

This first alignment is meant to ensure the proper rotational position of the astrometric eyepiece. Then, one has to move the pole star to 'position 16' on the linear measuring scale, see 'Bild 3'. This will make sure the polar axis is aligned properly, without needing to know date or time. Great, isn't it? It took me about 30 minutes to do this - kneeling on the floor, as I have the mount on a comparatively small pier of less than 80 cm height. Anyway, I guess that after some practise it should be possible to do this in a few minutes.

A copy of the alignment instructions, showing the reticle of the Meade astrometric eyepiece and where the pole star shoud be.

click to enlarge

The William on the MAM-020 underneath my Cassegrain with 6" guide scope, after the observations. The mount is polar aligned now and when the big scope is moved on the other side it can see about 40 % of the sky - enough for some testing.

Now comes my next test - I point the star to alpha Cygni and use the FS2 by M. Koch to set this as a 'reference star'. Going through the menu is straight-forward and intuitive after having spent about 10 minutes going through the instructions (and that I did about 2 weeks ago). Use 'shift' (a button on the left side of the box) and the right push-button to go into the menu, then use the 'right' button as 'enter', 'up' and 'down' to select, and 'left' to go back out.

After having selected alp Cyg as my reference star, I again use 'shift' and the 'right' button to go into the menu, I realize that by pusing 'up' just once I arrive at 'Gehe Zu' which means 'GoTo' and I ask the mount to go the M15 which I know from looking at the sky should be visible through the scope. I press 'go' and - bingo! Something that looks like a globular cluster is visible about half way between the center of the field of view and the edge in my 12 mm Nagler eyepiece (yielding about 70x I guess).

So, the GoTo works and is easy to use! However, after a few minutes, M15 is gone. I say 'GoTo M15' again and it's there again. Hm. I realize that I had the tracking rate set to 'Earth' which means it doesn't track... I change it and try again, and indeed M15 is followed nicely in the eyepiece.

I also look at the Ring Nebula and M31 for some fun. I ask the mount to slew to M33, but in my opinion it's about 1 deg off. To be checked...

Congratulations to both Manfred Mauz for a nice piece of hardware, and to Michael Koch for a mount control which is reasonably easy to use. I just wish he'd add some memory to store the Periodic Error Correction... But this will come later.

cu Detlef.

Created by dvk,  25 Dec 2008, added links to other pages on same level 26 Dec 2008.
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