CORONADO PST Probs

[mjpfc]

Morning Folks,

Just wondering if anyone new of an easy fix before I try and open up the scope or call coronado/meade.

I have had problems with the ETALON control on the scope, in that It does not appear to change the 

view-details at all, and I cannot make out (hardly) a thing either on the disc or off the limb.

Currently I am sometimes seeing the black spot of a larger umbra, but nothing else.

(Granted, there was very little to see in W/L either the other day when I last observed) but this has been the case with plenty

to see through my W/L filter on my newt.

There are some screws holding the box together and wondered if any of you guys new of a reason why undoing-them would be a good idea,.....

Or if I should try the makers.

Mick      IOW 

 

[Moonshane]

are you tuning the etalon? you do this by turning the large rubber collar in front of the black box (as you are observing).

[Moonshane]

ps in mine I turn it to the left (counterclockwise) when sat at the scope all the way to get best results.

[mjpfc]

Aye guys,

I've had it full clockwise, full counter and all stations in between. It used to highlight different details better in different positions but now it appeard to have stopped doing anything to the view.

I have spent hours tweaking the Etalon control, and also the focuser to see if that helped at different positions but though the focuser still works the other is not working at all now, and has not worked very well for a couple of months.

Mick.

[Moonshane]

Is the objective blue in colour (coatings) or gold? Can you upload a pic?

[moriniboy]

Hopefully this has not been dropped, the fact that etalon tuning does not do much suggests that it may have become decontacted, hope I'm wrong with this assumption.

Undoing the box just gives access to the focusing mechanism (see photo)

[mjpfc]

The Aperture lens (coating) is blue in colour.

I bought it in 2009 and it has worked well since until..........

Mick

[Stu]

If you carefully pull the rubber cover off the Etalon tuning ring, it gives access to a grub screw which connects it to a series of positions in the etalon (I think!) It is possible something has come undone in there so that the tuning ring no longer turns the etalon.... worth checking

[Moonshane]

Maybe this will help. Scroll down a fair bit

https://brierleyhillsolar.blogspot.co.uk/p/equipment.html

[mjpfc]

Cheers me hearty

much appreciated, I'll give it a really careful go

 

Mick

[mjpfc]

Cheers to you as well stu,

rubber bit off, have found the screw..................

[Moonshane]

Good luck buddy

[moriniboy]

The screw locates into one of these holes, please mark which so it can be returned to original settings.

This photo is when the sleeve which carries the rubber grip has been removed.

If you are intending to get to the etalon you will need to unscrew the gold tube as well.

Also have you checked the erf, the etalon my be fine but the erf coatings could be degraded, this could affect the views as well.

Also try this

 

[Merlin66]

Re-setting the M2 screw by one or maybe two holes should improve the situation.

I would NOT recommend doing anything else at the moment.

There are further checks you should consider before attempting to remove the etalon.

You could cause more problems.