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Celestron nexstar evolution 9.25 + TV Everbrite diagonal

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#1 aguadero

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Posted 05 February 2018 - 06:13 AM

Hello I have a Celestron Nexstar Evolution 9.25 with Alt-Azm mount. I would like to have a good diagonal, I was thinking about buying a  Televue Everbrite + long adapter for SCT. But I am worried about the clearance with the mount.
With my current diagonal (GSO dielectric) the clearance, when I am pointing to the zenith is small.
Anyone with this telescope has the Televue diagonal + long adapter ? Any recommendations?

Thanks



#2 junomike

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Posted 05 February 2018 - 05:11 PM

Why not the normal 2" - SCT adapter with the TV Everbrite?



#3 skaiser

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Posted 05 February 2018 - 07:11 PM

Another way to consider keeping good clearance.

Use the Wedge.

I know it adds a lot of weight, but it is nice to use when worried about clearing everything when slewing around.



#4 aguadero

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Posted 06 February 2018 - 02:46 AM

Thanks both

What is the normal SCT adapter? i think the short adapter is discontinued

 

thanks



#5 junomike

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Posted 06 February 2018 - 04:54 PM

I consider this one as normal length.

A "Shorty" VB doesn't offer much more as a regular Diagonal  Nosepiece  sticks out anyhow.

The "Shorty" VB is only short when used with the shorty Nosepiece (also discontinued) as seen in this post.



#6 aguadero

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Posted 07 February 2018 - 04:32 AM

Thanks Junomike, do you think with the "normal adapter" and the TV Everbrite diagonal I will have problems when I point to the zenith.

With my current GSO SCT diagonal the distance between the diagonal and the mount is very small.

Thanks again.



#7 BlueAstra

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Posted 07 February 2018 - 10:44 AM

I use one of these on my Evolution 9.25". Very easy to lock/unlock a diagonal or other accessory. I think either with this or the other adapter you will have a problem at near zenith. I actually take the diagonal out when the Evo does a Starsense alignment. I think you can also set max/min altitude limits in SkyPortal.



#8 junomike

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Posted 07 February 2018 - 05:15 PM

Thanks Junomike, do you think with the "normal adapter" and the TV Everbrite diagonal I will have problems when I point to the zenith.

With my current GSO SCT diagonal the distance between the diagonal and the mount is very small.

Thanks again.

Looks like the Baader ClickLock and Blueball VB's are similar in length.

This user seems to have enough clearance (see Post #10).



#9 parebal0

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Posted 07 February 2018 - 07:27 PM

Thanks Junomike, do you think with the "normal adapter" and the TV Everbrite diagonal I will have problems when I point to the zenith.

With my current GSO SCT diagonal the distance between the diagonal and the mount is very small.

Thanks again.

I have the 9.25 Evo and everbrite diagonal.   I do need to make sure that I slide the scope as far forward as possible to ensure I get clearance at or near the zenith.  And make sure you don’t have any tall eyepieces in the eyepiece tray closest to the diagonal.  I usually keep my ethos 13mm in the diagonal and it provides a reasonable counter balance with its 15lb weight.   Ok...ok... just a bit of an exaggeration, but it is one heavy beast!  grin.gif  hope that helps... Peter A.



#10 aguadero

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Posted 08 February 2018 - 03:49 AM

Thanks both.

Junomike it seems is the 1.25" Baader diagonal. Don't do think so? I would like the 2" one.

Parebal0 do you have the 2" TV Everbrite or the 1.25"? Which adapter are you using?

 

Thanks again



#11 parebal0

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Posted 08 February 2018 - 03:55 AM

Thanks both.

Junomike it seems is the 1.25" Baader diagonal. Don't do think so? I would like the 2" one.

Parebal0 do you have the 2" TV Everbrite or the 1.25"? Which adapter are you using?

 

Thanks again

I have the 1.25 everbrite, and the supplied visual back from Celestron, no other adapters.   Peter A.



#12 junomike

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Posted 08 February 2018 - 05:22 PM

Thanks both.

Junomike it seems is the 1.25" Baader diagonal. Don't do think so? I would like the 2" one.

Parebal0 do you have the 2" TV Everbrite or the 1.25"? Which adapter are you using?

 

Thanks again

No It's definitely a 2" Diagonal.  In Post #6 (3rd Paragraph) he explains the optical train and states it's a 2" BBHS.



#13 aguadero

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Posted 09 February 2018 - 11:53 AM

ok thanks junomike, Do you think there will be difference with my current diagonal (GSO) or I am going to waste money.



#14 junomike

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Posted 09 February 2018 - 05:59 PM

ok thanks junomike, Do you think there will be difference with my current diagonal (GSO) or I am going to waste money.

Other than maybe being a bit shorter I doubt you'll see any difference (at the eyepiece).

One nice thing about Diagonals is they can go from OTA to OTA so If you do end up with a premium Diagonal, it can grow with you.



#15 aguadero

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Posted 12 February 2018 - 06:43 AM

if is a bit shorter, it will be worth it, Thanks for your help



#16 spongebob@55

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Posted 12 February 2018 - 11:58 AM

I have the Televue Short VB (https://agenaastro.c...r-acs-0004.html) on my SCTs.  Its 40mm tall, which is 8mm shorter than the Blue Fireball at 48mm.   Once screwed onto my 8" Evol, it has 30mm of internal length for a diagonal's nose piece.   I use a Baader 2" diagonal and a 1-1/4" Baader Prism diagonal with a 2" nosepiece.   Plenty of inside clearance.  Discontinued, but worth the 'wanted' ad on CN......

 

Now you might consider the WO SCT diagonal.  Quite short.  As measured by Astroagena, adds ony 14mm from the side of the diagonal to the mating lip of the scope's VB.   https://agenaastro.c...agonal-sct.html   There's also a twist lock version of it and also just a SCT adapter nose piece.

 

Good luck

Bob



#17 Michael_Swanson

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Posted 12 February 2018 - 10:12 PM

The shortest possible 2" diagonal is the Baader Maxbright or the Baader Clicklock.  The nosepiece can be removed and the diagonal can be screwed directly to the rear cell (or in the case of the 11" and 14" SCTs and the 9.25" Evolution SCT, onto the 3.25" threaded adapter).  See these two reviews at my website for a picture:

 

http://www.nexstarsi...ockDiagonal.htm

Figure 3 shows the arrangement I'm describing.

 

http://www.nexstarsi...erMaxBright.htm

Refer to Figure 2 in this article.

 

One caveat; when attached this way the clear aperture is reduced to about 1.5" which will vignette on wider field eyepieces when compared to the full 2" fieldstop available with a 2" diagonal.  This article at my website describes what you need for a full 2" clear aperture on 11" and 14" SCTs and on the Evolution's version of the 9.25" SCT:

http://www.nexstarsi...nchAdapters.htm

 

Best regards,
Mike Swanson
Author of "The NexStar Users Guide II"
Author of "The NexStar Users Guide"
Author of "NexStar Observer List"
http://www.nexstarsite.com/



#18 aguadero

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Posted 14 February 2018 - 02:36 AM

Amazing  review... thanks all.

I think in my case (Nexstar evolution 9.25 XLT) I can't use the 3.25 adapter is only for de Nexstar Evolution HD

I have to use https://www.firstlig...-meade-sct.html

I hope with this adapter and the Baader diagonal has a full clear aperture and enough clearance to point to the zenith

 

Thanks



#19 chuckscap

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Posted 14 February 2018 - 09:14 AM

In my opinion the answer is a counterweight so you can push the OTA more forward in the dovetail and still have it pretty much balanced.  I bought this counterweight (see it on the handle of my Mak/Cass which is the same length as a C9.25) I bought for about $20. Sorry to keep posting this but the question keeps coming up.  I have an AP 2" Maxbright Diagonal installed so it's pretty much worst case?  It clears by about 1/2" at zenith.

 

 

 

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Edited by chuckscap, 14 February 2018 - 09:16 AM.



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