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So I ordered new 180mm F7 TEC. Now what?

Refractor
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#51 drprovi57

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Posted 04 December 2021 - 03:10 PM

Jason, what wavelengths do you use your ERF filter on?

Since I already have double stacked 100 mm Lunt, I plan to try the TEC 180 on Ca K, Sodium and white light.

Slav

Primarily for Ha and occasionally white light - I use an additional 2" UV/IR filter before diagonal - in my case I have the Combo Quark Ha version without the built in 4.2X telecentric barlow (I recommend getting the Standard Quark with 4.2X barlow) - I use my system on my refractors and Questar 7 f/15 and 2-5X barlows.  

 

Jason 



#52 C0rs4ir_

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Posted 04 December 2021 - 03:11 PM

"If you have the sophistication to order a TEC 180 I doubt you really need our help."

 

Wanted to say the same. With 180mm aperture you better know what you are doing with H-alpha or Ca-K.

I´d go for a front mounted Aries ERF + rear mounted 2" erf dependent on the wavelength. + the rear mounted etalon filter.

 

For the sodium wavelength im not aware if a front ERF exists.

 

Once you are at ~f/30 with that scope you are @ around 5m+ of focal length, then you need good seeing or a good reducer.

 

 

About the ADC: yes i would get an atmospheric disperse corrector. i wouldnt like to spend the money on such a perfect color corrected telescope just to have the atmosphere preventing it from performing to the full potential.


Edited by C0rs4ir_, 05 December 2021 - 03:44 AM.

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#53 gnowellsct

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Posted 05 December 2021 - 10:05 PM

 

When a telescope is mounted on EQ mount and slews with the binoviewer and eyepieces in it, it creates lot on torque on the focuser and the diagonal (because the whole telescope tube rotates). Then the binoviewer has tendency to "unscrew" or slip. Seeing the binoviewer "swing around" always scares me to death. In Alt/Az, the whole Bino set up stays straight up.

The feather touch 3-in on my cff telescope can handle this kind of situation but the FT 2.5 in on my stowaway  cannot.  You should make sure with Yuri that you're getting either the 3-in or the true three inch focuser.   Then put the astrophysics adapter on the rear as I did for my cff.  I suppose I should dig up a pic.

 

Nonetheless if you can figure out a good altaz mount no reason not to do that. Most of the altaz mounts I've encountered don't have as much stability as the gems.  But I have by no means sampled all of what is out there. I seem to remember Losmandy has an ALTAz option these days but I haven't looked into it.  

 

It is true that the HD tripod is your best bet.  You'll need some kind of extender probably.  Tripods are a bit tricky with big refractors due to the clearance when you want to view near zenith.

 

 



#54 gnowellsct

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Posted 05 December 2021 - 10:18 PM

This is  ada2003a visual back which was my personal spec for the FT on the back of my CFF.  The FT 3-inch was also my spec.    

 

cff focuser close up with solar - cn size - edit.jpg  

 

 



#55 gnowellsct

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Posted 05 December 2021 - 10:25 PM

I like the arrangement ADA2003A so much I had a custom adapter made to put one on my c8.  Now all my scopes have this rear adapter including the c14 (AP has made that part for a long time, no adapter needed) and no matter what scope I'm using I have the same rear arrangement which (no surprise) works surpassingly well with the rock solid AP diagonals.  I put one on my Stowaway as well.  (IIRC, it came with an FT visual back).  

 

AP makes a light duty visual back for the c8 and 9.25 and they thought I was nuts to want an ADA2003A on my c8 and said so politely but firmly.  I haven't regretted it.  

 

And yes that it is a cheap piece of plastic plumbing serving as "fine focus" next to the ADA2003A and maybe out of place next to an AP diagonal and XW40.  There's a bit of the dob guy in me.  Whatever works.  --GN

 

c8 visual back in the field.jpg

 

 

 

 

 

 



#56 gnowellsct

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Posted 05 December 2021 - 10:28 PM

Get the best focuser you can regardless of mount choice, IMO. --Greg N

 

Edit: and I'd add that it's ok with the focuser to be "thinking forward" as you may get into things that you had not anticipated.  For one person it might be binoviewers, for another it might be solar h-alpha or photography.


Edited by gnowellsct, 05 December 2021 - 10:38 PM.


#57 slavicek

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Posted 06 December 2021 - 09:56 PM

Get the best focuser you can regardless of mount choice, IMO. --Greg N

 

Edit: and I'd add that it's ok with the focuser to be "thinking forward" as you may get into things that you had not anticipated.  For one person it might be binoviewers, for another it might be solar h-alpha or photography.

Thanks for the info. The TEC is coming with 3.5" Feathertouch focuser and with 2" adapter but I am not sure which type of adapter. That ADA2003 is certainly nice adapter.




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