Info: Takahashi Mewlon 210 - Check up and collimation

Info: Takahashi Mewlon 210 - Check up anbd collimation

A Takahashi Mewlon 210 found its way to us:

The Takahshi Mewlon210 is a Dall-Kirkham telescope from the Cassegrain system. It has an ellipsoidal primary mirror and a spherical secondary mirror, which was chosen for the best possible imaging on the optical axis. The primary mirror has a focal ratio of f/5, the secondary mirror extends the focal length to 2415 mm. 

What immediately caught the eye, of course, is the cover of the entrance aperture: a perfectly fitting cover made of imitation leather.

Why did it come to us? The owner asked for an inspection and collimation of the telescope. There had been damage to the secondary mirror, as the aperture tube installed inside had fallen exactly onto it.

Here you can see the secondary mirror with its aperture tube and the damage. We removed the mirror to see if it was perhaps just a grease rim. Unfortunately, wes really a scratch.

Here are a few pictures of the removal of the secondary mirror:

Front view of the Mewlon210 without the cover cap.

Here the cover cap was removed to access the secondary mirror screws. 



A little tip: the nut in the centre should be left alone. Compared to telescopes like Skywatcher or Celestron, the outer screws are lag screws (on the other telescopes they are push screws), so only these need to be loosened to remove the secondary mirror.

This one: no screwing!



This is how the secondary mirror holder looks on the obective side: 

The notch for the central pressure screw can be seen very nicely.


The whole thing was reassembled and collimated.


It was fun to check it. Really very finely and precisely made, you could feel it with every grip.