For the "Meadologists" out there... what scope is this?

[MaartenM]

Hi all, I need some help to identify what model this telescope is. It is obviously a Meade 10" SCT but that is where my identification skills falter... I've been googling around and it is definitely an old beast, heavily modded by a previous owner. It would be nice though to know whether this is/was a 2080, an LX5, an LX50 or still something else. It was converted to GEM obviously, and also the finder scope is not original (it's an Orion (or the like) small 6x30 affair). The OTA is flocked as far as I can see and the whole OTA was, or more likely has been, spray painted matt black at some point in its life...

Finally it has a pin of unknown functionality sticking out of its back next to the eyepiece hole. The pin is not moveable in any way by hand, it may be stuck or in fact fixed by design but I don't dare to take pliers or something to it to see whether it can be moved for fear of breaking something.

To me, also after looking at Uncle Rod's used SCT guide, many Meade OTA's especially from the early years look quite alike. But no doubt there must be experts who can shed some light on what exactly this is.

Many thanks in advance for any tips!

 

Best regards,

Maarten

[michael8554]

Must be very early as it doesn't have High Contrast or Ultra High Contrast on the front ring, or a Primary Mirror Lock on the back.

But the pin on the back may be part of a DIY lock.

Michael

[Merlin66]

2 hours ago, MaartenM said:

Finally it has a pin of unknown functionality sticking out of its back next to the eyepiece hole

This pin seems to be sitting in the hole used by the mirror lock screw. It was recommended before transporting the Meade OTA to insert the (1/4"?) screw to hold the mirror in place.

On the MAPUG site there was details of how to re-use this hole to allow a proper mirror lock attachment to be mounted - to reduce mirror slop during use.

http://skymtn.com/mapug-astronomy/MAPUG/ImgShift.htm#anchor1445909

The various Model numbers quoted refer more to the mount the OTA was fitted to, rather than the OTA itself.

If the main mirror and corrector are OK, check the collimation and enjoy it.

 

[MaartenM]

Thanks all for the responses.

It is indeed an old beast so the absence of coating indicators is no real surprise...

Further inspection shows that immediately next to the focuser there is a small hole, covered with a little plastic cap, which I'm sure must be the hole that will take the bolt to secure the mirror for transport... The various bits and pieces of info on the web indicate that the hole is next to the focuser. So it would seem that the "pin" on mine is not in the transport locking hole but was put there on purpose - some other info I found suggests that the best place for  the mirror lock replacement is on the OTA back plate opposite the focuser.

It looks like this is a Meade 2120, heavily modified by a previous owner ("McGyver modified" as someone on another forum said). I guess the pin has something to do wih locking the mirror but the thing is stuck... maybe that's what it is meant to be...

Meanwhile, mooching around based on the various comments, I did find out that the amount of play in the focusser (almost 3/4 of a turn) seems excessive... Focusing the thing for photographic purposes is indeed a chore so maybe I should look at that first...

All further comments much appreciated!

Best regards,

Maarten

[MaartenM]

Hi all, a bit of an update or rather another question. The pin referred to in the pictures and posts above actually moves in and out with the turning of the focus knob. That means it is effectively connected to the mirror, so it seems pretty sure it has been added to address mirror shift in some way. The thing is, as can be seen in the picture above, it is not a screw, it isn't threaded, there is no spring. It is just a little rod, maybe 5mm thick, attached to the mirror. Strange enough it doesn't stick out exactly perpendicular to the back of the scope but I can't figure out whether that is just sloppy drilling/fixing or whether it's intentional.  If I focus, there is some mirror shift (not unheard of in these old sct's) and if I push the pin I can correct the shift somewhat.

Does anyone have any idea how this may have worked or is intended to work? 

Thanks in advance! 

Maarten