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Meade Model 230


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#1 Starga45

Starga45

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Posted 25 April 2021 - 06:03 AM

I need an eyepiece and a manual for a Meade model 230 telescope. The telescope information card says D=60mm F=700mm f/11 and the eyepiece opening is 1.25" wide. Can you recommend an eyepiece that would work well with this model? Can I purchase any 1.25" eyepiece or does the eye piece need to be a specific mm? 

 

I looked on the Meade website and Ebay for a manual but did not see any listings. Would you know where I can get a manual for this telescope?

 

Thanks!



#2 MistrBadgr

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Posted 25 April 2021 - 07:38 PM

Hello Starga45! :)

 

 

I have looked around some, but have not found that specific manual.  I will ask some people I know and see if they have a pdf.  As an alternative, the Infinity 60&70 manual on the Meade website has essentially the same mount that your scope has.  the Infinity 60 has a different finder on it and has an 800mm focal length instead of 700.  The basic instructions for any scope that looks like yours should be the same.

 

With the eyepieces I am going to talk about, the information applies to any brand, but I will be thinking about the Meade 4000 series Super Plossels. The closest proper spelling that matches the German letters of the man's name is Ploessel, but that is not how any of the big manufacturers spell it.  I will use his correct spelling in an attempt to keep what I say relatively generic.  These are good enough to last a life time, even if you really get deep into the hobby.  If you do and buy better, more able, and much more expensive eyepieces, a good set of Ploessels comes in handy a lot of times when you do not want to take the really expensive ones out.

 

As for eyepieces, your scope will be very forgiving when it comes to eyepieces, with its relatively long focal ratio.  When using my Infinity 60, I normally start with a 32mm Ploessel for finding purposes. That gives me a 2 degree piece of the sky, called true field of view (TFOV).  The image that you see through the eyepiece will look like 50 degrees or apparent field of view (AFOV) and is close to the widest field of either type you can have through a 1.25 inch eyepiece.  A 40mm will give a tiny bit wider of true field, but looks narrower inside the eyepiece at 44 degrees, which is absolutely the widest it can go at that focal length.  The image in the 40mm will not have quite the contrast,  so I like the 32mm a little better, even though there is nothing wrong with a 40mm.In your scope, at 700mm focal length, the 32mm will give you about 22X with a TFOV of about 2 1/4 degrees.  This is a reasonable starting magnification with a field wide enough for most large objects.

 

From the 32, I normally step down to a 20mm Ploessel.   In your scope, that would give you 35X and a TFOV of about 1.5 degrees.  This is a good field for a lot of star clusters, some galaxies and nebulas. 

 

All of the eyepieces from 26 degrees and shorter in the Meade 4000 series Ploessels have an AFOV of 52 degrees.

 

From the 20mm, I drop to the 12.4mm Ploessel.  In your scope, that would give you 56X with a TFOV of about 0.9 degrees.  This will be a good magnification for most of the planets with this scope.

 

For a couple different reasons, I recommend people start out with these three eyepieces and then add a 2X Barlow lens, or something similar.  For your scope, a short Barlow will fit into your diagonal better and the Meade 4000 series Barlow is a relatively nice one.  I can give you some tips on how to help its performance if you are interested, along with your scope's objective lens.  This 2X Barlow normally goes into your diagonal,with the eyepiece going into the Barlow.  The 32mm eyepiece will then work like a 16mm, about half way between your 20 and 12.4mm.  The 20mm will act like a 10mm and will push the magnification past your 12.4mm eyepiece to 70X.  Putting the 12.4mm eyepiece in the Barlow will give you 112X, which will be a good Moon magnification.

 

Normally, conventional wisdom says the top magnification that is useful with good sky is around 2 times the diameter of the objective.  For your scope, this would be 120X.  Therefore, you are pretty much there, with this setup.  You may want others in the series, which is fine.  I am simply suggesting what I think is the minimum to help you "cover the bases."

 

Some other bits of information:

 

If you put the Barlow in front of the diagonal, then put the eyepiece into the diagonal, the magnifying effect of the Meade 2X Barlow becomes roughly 3X.  Sometimes a particular model of scope will not come to focus while others will.  You would simply have to try it and see if it works in your scope.  That will give you some other magnification options to try.  Sometimes one combination works better than the other.

 

The distance from the eyepiece to your eye is called eye relief.  For a Ploessel, the eye relief is roughly 2/3 of the focal length of the eyepiece.  For the really short focal lengths, this distance is too short for people that must wear glasses.  People that are short or far sighted can use a telescope without their glasses and simply adjust the focus.  People with severe astigmatism will need their glasses.  People that need their glasses can use a few of the longer focal lengths and get several different Barlows with various magnifications to make up the difference.

 

I will be putting a post on the board shortly about things they can make or modify to help shorten what I call "wiggle time" on a scope.  All scope wiggle some when you focus them, except maybe really big ones.  If the wiggle starts lasting more than a couple seconds, it can get aggravating if you have to refocus a lot...depends a lot of the person.

 

If I find out anything about a specific instruction book for your model, I will post it here.  If anyone else reads this and has something, do not hesitate to speak up.

 

Hope this helps,

 

Bill


Bill Steen, Sky Hunters' Haven Observatory, Broken Arrow, Oklahoma




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