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A complimentary CAT?

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#1 Seiko4169

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Posted 13 July 2013 - 08:21 AM

I've jumped ship from the world of GOTO Cats to manual alt az mounts and refractors but with only a 120mm TAK TSA the globular clusters are really poor from my light polluted garden.

I'm using the Skywatcher Skytee 2 mount that in theory will allow me to mount two scopes and I'm thinking of adding an SCT so that I can have the best of both worlds.

Although I could theoretically invest back into the CPC, Nexstars etc I'm actually enjoying finding my targets so I'm thinking about just the OTA option at the moment.

With that in mind what SCT size and model would you suggest to

A) simultaneously compliment the TAK views
B) really bring the globulars to life
C) be manageable on the Skytee2 mount with the TAK

Thanks

#2 MikeBOKC

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Posted 13 July 2013 - 02:00 PM

What's the weight capacity for that mount? If I was looking for an SCT to compliment a 120mm refractor I would go with the 9.25.

#3 SteveC

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Posted 13 July 2013 - 03:08 PM

I've never owned an SCT, but as someone who has had a TEC140 and an 7" Intes Micro Mak side by side, I can say that they probably won't be acclimated to air temperature at the same time, especially when the temperature is dropping. Granted, my Mak has a lot of glass and metal, but I found that spent more time looking through the TEC140 and waiting for the Mak to catch up. I'm not trying to dissuade you from trying the combo, but to advise that it may take more patience in setting up and viewing depending on the size of the SCT.

#4 Eddgie

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Posted 13 July 2013 - 03:14 PM

I read your post on the Refractor forum and bit my tongue because there is so much "Refractors are better than anything else" rhetoric, but as you have quickly realized, for the vast majority of targets out there in the world respond better to aperture than any other telescope attribute.

All that being said, now you have the situation that you have a mount that is not Go-To and will not be capable of holding enough aperture to do some serious deep sky.

Alt Az mounts are not well suited to large SCTs due to the fact that their focal lengths mean that they are often used at fairly high power.

I would go as big as I could for the mount though. If it would hold a C11, I would try that. If not, a C9.

If you are not 100% weeded to a Cat, why not consider a Go-To Dob?

If you have a place to store it and attach wheelbarrow handles to move it, a Go-To dob can be out of the door and running before you can carry out your mount and your two telescopes that you would have if you put a C9 or something on your current mount.

12" Go-To dob for $1800....

#5 Seiko4169

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Posted 13 July 2013 - 06:35 PM

Thanks Eddgie and yes totally agree the frac is nice, quick to cool and shows lovely wide views buts its no magic scope and aperture clearly rules. Alas I really don't have enough storage space for a big DOB so will need to go with a CAT. I'm just not sure how much the mount will take. It's 15kg per side but you never really know until you try it.

The 11 of course would be superb but I do wonder if that's pushing things a bit too far. A lot of EQ mounts struggle with a C11 so it might be a bit to big.

#6 Seiko4169

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Posted 13 July 2013 - 06:38 PM

Thanks Mike, Steve,

Yes cool down size is a consideration along with the best size. I always thought the 9.25 and 11 where too similar in size to ever go with the 9.25? Perhaps it's the max weight the mount would take?

It's rated at 15kg per mount point so the C11 comes close.

#7 Mkofski

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Posted 13 July 2013 - 11:33 PM

I had a SkyTee 2 and used it with Celestron 8" and Meade 10" SCTs. The 10" Meade was a bit too much for the mount. This was with about 15 pounds of refractors on the other side.

#8 GlennLeDrew

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Posted 14 July 2013 - 01:28 AM

Beware those complimentary CATs; they're smooth talking customers! :grin:

#9 Bill Barlow

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Posted 14 July 2013 - 03:15 AM

I would choose the C9.25 as it weighs around 20 pounds and will out perform the TSA 120 on deep sky targets. I also use altaz mounts with my scopes, including some fairly large cats..a Meade 10 ACF and a C14. I also like to find my targets by star hopping and using the S+T pocket sky atlas, much more fun and rewarding for me. Good luck..

Bill

#10 Seiko4169

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Posted 14 July 2013 - 03:31 AM

Seems the 9.25 is the 'goldilocks' for the mount. Looks like the 11 is too big but would the now infamous HD versus small aperture increase dilemma raise its head?

I know that purely cosmetically the Edge HD would look nicer with the TAK on the mount :grin: but I don't want to pay so much the Edge Hd 9.25.

My concern with the Edge 8 is that it won't guarantee to beat the TAK as its not quite large enough?

#11 Bill Barlow

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Posted 14 July 2013 - 04:02 AM

I would think that the TSA 120 might beat or at least stay with the edge 8 on planets most of the time, but not on deep sky targets. The standard C9.25 would give the Tak a run for it's money or beat it on decent seeing nights on planets and noticeably pull away on deep sky objects.

Bill

#12 Seiko4169

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Posted 14 July 2013 - 05:24 AM

Thanks Bill, that's my gut feeling too. The edge 9.25 is expensive in the UK though! It's nearly twice the price of the edge 8!!

With my ES 100 eyepieces though the Edge would seem a natural fit over the regular?

#13 Scott Beith

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Posted 14 July 2013 - 07:51 AM

The long focal length will be rough on a non-tracking mount.

#14 McUH

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Posted 14 July 2013 - 09:09 AM

C8 or C9 should do well. On Skytee2 I think you can have counterweights with scope on the shorter arm, so it does not need to be exact match. C11 might be too heavy.

Edge is fine, but I don't think you really need it in this situation. For low powers the 120mm will be good, and for high powers standard SCT should do Ok.

Manual tracking is not so bad when you get the hang of it. I use C9 on AltAz, 200x is not problem, 300x requires nudges often, but still Ok. 500x is tricky and no longer comfortable, but then such power is required/possible only very rarely. Wide-field eyepieces will help a lot in this case. Since Skytee2 has slow-motion controls the high power tracking should be even easier for you.

I have 120mm refractor and C9 Edge in light polluted skies, and the difference on most DSO's is really big. C9 will definitely bring the bright globulars to life compared to 120mm.

#15 SteveSMS

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Posted 14 July 2013 - 09:23 AM

Hi Seiko,

I have the Skytee2 and I have used an EdgeHD 8 and a 120ED f7.5 side by side and it works fine. I have the Skytee mounted to an Orion pillar and I use the heavy (2" leg) version of the CG5 for the tripod. It's a heavy setup but it is stable.

Clear Skies,

Steve

#16 Seiko4169

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Posted 14 July 2013 - 09:23 AM

Thanks, yes, the C9 seems to fit the bill but the Edge price is a problem as I'd love the Edge version

:-/

#17 Seiko4169

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Posted 17 July 2013 - 01:06 PM

Well, I've got a regular 9.25 arriving so hopefully globular clusters will come back to life?

Certainly hope it's not a lemon!

#18 wargrafix

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Posted 17 July 2013 - 01:51 PM

so far my regular 9.25 is performing wonderfully. You won't regret it! :-)

#19 Seiko4169

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Posted 17 July 2013 - 03:17 PM

Yes, I'm looking forward to it arriving but can't help but feel the dread of the variable quality that every SCT brings!

:-/

#20 mskillen

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Posted 17 July 2013 - 04:38 PM

Yes, I'm looking forward to it arriving but can't help but feel the dread of the variable quality that every SCT brings!

:-/


Saw your Comment, and since I am looking for a new SCT I would like to know what differences I would be looking for.

What makes a good one vs a bad one, and is it something that you can correct?
If it was a mirror issue I can see that would definitely be an issue, but I have heard others make similar comments about scope quality issue.

Just asking Thanks
Mark

#21 WesC

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Posted 17 July 2013 - 08:02 PM

I think that 9.25 on one of those sexy Nova Hitch mounts would be awesome.

#22 Seiko4169

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Posted 18 July 2013 - 01:38 PM

Yes, I'm looking forward to it arriving but can't help but feel the dread of the variable quality that every SCT brings!

:-/


Saw your Comment, and since I am looking for a new SCT I would like to know what differences I would be looking for.

What makes a good one vs a bad one, and is it something that you can correct?
If it was a mirror issue I can see that would definitely be an issue, but I have heard others make similar comments about scope quality issue.

Just asking Thanks
Mark



Hi Mark,

A simple star test will tell you a lot.
Mirror flop or hopefully lack of.
Smoothness of focusing,
General quality of fit and finish.

All of the above have variations and I've had a large number of differences, I don't know if there is any science but the biggest wow I had was with a small cpc 800. The views were superb, globular clusters sparkled. It could have clearly been a large number of factors combining, great seeing and good optics etc but none of my subsequent scopes have matched it. I didn't realise I'd got lucky until after I'd sold it and tried another batch of scopes.

I'm hoping I get lucky with the 9.25.

:smirk:






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