mesu 200 pec

[astrorick]

Does enybody know how to measure the PE on a mesu 200 mount (with PECPREP) or any other ways?..

many thanks rick

[andrew s]

Rick - I don't think it will have a conventional periodic error as it has a friction brive. The worm is the major source of PEC in a conventional mount. In any case it would be measured in the same way but I suspect it will be below the seeing in most UK situations. Andrew

[astrorick]

Andrew

Thank you very much for your help, much appreciated

Rick

[chrisshillito]

Rick,

Take a phd log with guiding output turned off (having previously calibrated) and then load into PECPrep (remembering to enter focal length, pixel size and declination).

If you are expecting a low amplitude PE then make sure you're using a decent image resolution on the image being sent to PHD.

PECPrep's filters can be used to filter out random seeing fluctuations.

Chris.

[ollypenrice]

The friction drive doesn't eliminate PE, it eliminates backlash. While the Mesu is very accurate it does have some PE, as I think you'll confirm. it's low and it's slow and it guides out superbly - and because there's no backlash that source of guiding error is gone.

Olly

[astrorick]

Rick,

Take a phd log with guiding output turned off (having previously calibrated) and then load into PECPrep (remembering to enter focal length, pixel size and declination).

If you are expecting a low amplitude PE then make sure you're using a decent image resolution on the image being sent to PHD.

PECPrep's filters can be used to filter out random seeing fluctuations.

Chris.

Thank you Chris I will try and do that

[astrorick]

The friction drive doesn't eliminate PE, it eliminates backlash. While the Mesu is very accurate it does have some PE, as I think you'll confirm. it's low and it's slow and it guides out superbly - and because there's no backlash that source of guiding error is gone.

Olly

Hi Olly

Thank you for your comment and your explanation on the friction drive mesu mount, like you said, it has some PE but it guides quite well, how do you guide when you use your mesu mount, off axis, or a guiderscope?. I use a guiderscope but sometimes I get flexure, an of axis guider would be better, but I think I`ll have problems finding a good guide star.

Many thanks and clear skies

[ollypenrice]

Hi Olly

Thank you for your comment and your explanation on the friction drive mesu mount, like you said, it has some PE but it guides quite well, how do you guide when you use your mesu mount, off axis, or a guiderscope?. I use a guiderscope but sometimes I get flexure, an of axis guider would be better, but I think I`ll have problems finding a good guide star.

Many thanks and clear skies

We guide with a Lodestar and OAG on a 14 inch scope with 2.4 metres FL. We are sometimes limited by the seeing but when we have good seeing the mount is infallible. The other night the RMS was 0.33. It has now dropped precisely two subs since last Febraury, both consecutively on the same night, so I suspect it was just a cable foul up or something outside the mount's control. It really is a remarkable mount. I'd love one of my own.

Olly

[astrorick]

We guide with a Lodestar and OAG on a 14 inch scope with 2.4 metres FL. We are sometimes limited by the seeing but when we have good seeing the mount is infallible. The other night the RMS was 0.33. It has now dropped precisely two subs since last Febraury, both consecutively on the same night, so I suspect it was just a cable foul up or something outside the mount's control. It really is a remarkable mount. I'd love one of my own.

Olly

Thank you very much for your reply, I love the Mesu mount too and I'm slowly getting the hang of using it properly. I think I will probably get an off axis guider.

Thanks again Rick