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11" Teeter S.T.S.

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#1 mountain monk

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Posted 07 December 2012 - 11:09 AM





A fellow CNer wrote asking about my 11" Teeter. Since there has been relatively little comment here about these scopes, I've decided to post my reply. It is not a technical review--I'm not able to do that. It's a personal view of my scope.


Teeter 11” S.T.S.

The short of it: Rob is a great guy to work with, the scope is elegant, and it works great. Some considerations (I don’t have the technical competence to do more):

Delivery. The scope was late but the problem was with Waite--he was ill. Rob was always transparent about where we were in the process, and why. He provided photographs of it during the various stages of production. (I would post one here but I don’t know how to post photographs.) It was well packaged and arrived in good shape.

Be sure to tell Rob exactly what lenses you plan to use with it. Because of the in-focus required for my 31mm Nagler, the mirror was moved forward maybe ½”.

I got the Feather Touch focuser, though the Moonlight would have been fine, and perhaps has a greater range of focus (I don’t know). The scope was a 70th birthday gift from my wife, and I like Feather Touch focusers, so… An indulgence. I use it with a Paracorr II, which is not, IMHO, an indulgence.

At the right setting (it’s easy to adjust to that point), it will balance everything from the 31mm down to a 5mm Pentax XW—IF, IF, I don’t jar it while inserting and removing the lens—those darn safety rings! I like the stiffness/smoothness of the movements—just right for me. I’m sure there will be individual differences between scopes.

I am about 6’1”—or used to be—gravity got to me, I think. It is comfortable to sit at with the above setting, barely, and I like the rotating OT. But if I were taller, it would be marginally low at the eyepiece. It’s borderline low because of all that weight up front—the GLP and mount, the finder and mount, the focuser, the Parracorr II, the 31mm… That’s not a problem for me because I plan to put it on an equatorial platform. And I could, of course, readjust the OT when I changed out the 31mm or add some weight at the back—but it’s fine. With my adjustable chair, and one setting of the OT, the eyepiece height at 25 degrees and at zenith works for me.

The Waite mirror seems very good. I got it because I’m not quite immodest enough to believe my old eyes can see the difference between it and a Zambuto or a Lockwood--assuming there is one. If I remember correctly (from the literature Waite sent along) it is about 1/18th wave and about Strehl .96—.97. That’s after various kinds of data analysis that I don’t pretend to understand, and there’s a percentage in there that I don’t understand either. A better mirror, for sure, than my eyes will ever be able to take advantage of, now or in the future.

But more to the point: I trusted Rob to give me a good mirror, he tested it, and as far as I’m concerned he lived up to our agreement. Obviously, I do not know about the new mirrors, but again, I would trust Rob. I spent fifty years of my life figuring out whom to trust in high-risk situations, in the mountains and elsewhere, and I think I’m fairly good at it. I would trust what Rob says about the new mirrors he offers.

We had a lot of smoke from wildfires most of September, I was gone most of October, and we’ve had clouds most of November. Nonetheless, I’ve observed here under a blue zone sky, and once up at my gray zone site. Knockout views! How would a critical eye compare them to views in other 10-12” mirrors? I don’t have any idea.

Secondary was spot on at arrival. I moved it to make sure, and…moved it back! I used a sight tube. The primary was easily collimated with Glatter tools.

It came wired for my Sky Commander, and that, in turn, can be wired to my iPad running Sky Safari. A superb combination, I’m sure. At present I prefer hopping around, just looking at things. I don’t do lists; I’m not interested in pins---I’m too old for such things. I just want to look! “… at my back I always hear/Time’s winged chariot hurrying near…”

Next time (I would like to eventually get a larger Teeter) I will pay more attention to the placement of the finder (a 9x50). I would like it closer to the focuser. My mistake. I also use a GLP. According to the TeleVue calculator, the 31mm Nagler with the Paracorr II provides a 1.7-degree true field of view, a 6mm exit pupil, and 47x--that helps with finding things. With the 5mm I get about 290x and about 1mm. I have a 2x Powermate. That’s pushing 600x, far more power than my seeing can usually handle.

The scope lives outside on a dolly (hand cart) in a shady, screened-in porch. I roll it out to the deck or onto the lawn and turn on the fan for an hour. The fan is louder than I would like—a purr, not a rattle--but I would prefer something…well, just slightly audible. Unless the temperature stabilizes, I leave it on. The stabilization rate difference between the STS and my C8 is obvious, even when the latter is left out on the porch and used with the Lymax cooler. The Teeter wins.

I can move the OT and the box with a couple of velcro straps with handles, but if I was interested primarily in mobility, I would get the 8” version. The 11” is heavy but manageable, especially if (re Rob’s advice) if it is carried in a vertical position when setting it onto the cradle. When I went up to my northern site (over a rough road), I broke it down into three pieces. Reassembly was quick and easy and it required only a minor adjustment of the primary—an indication of solid construction.

In summary: I am very pleased with my 11” S.T.S. If I needed to travel to darker skies all the time or had to haul it up and down stairs, I would get the 8” S.T.S. If I didn’t mind messing with a regular truss Dob, I might get the 12.5” f5 Classic. As it is, I’m very pleased. :)

Enjoy the dark sky.

Jack Turner

---------------------
NP-101 on a DM-6 with Sky Commander
C8 circa 1990
Teeter 11" STS
Zeiss, Fujinon, Nikon, Vixen binoculars

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#2 Mike B

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Posted 07 December 2012 - 12:01 PM

Nice overview, MM. :grin: I dunno how to rate scopes any better... even less their reviews. But after reading yours, i wish i could take a look thru that scope. :waytogo: It sounds like a winner. And once again, it clearly points to Rob Teeter as a marvelous builder of such things!

Rock on :rockon:

#3 lcaldero

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Posted 07 December 2012 - 12:05 PM

Thanks for the review. I am interested in a Teeter STS and a first hand detailed report from an owner is really helpful.

#4 starman345

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Posted 07 December 2012 - 12:09 PM

great stuff Jack, thanks for posting it. I wish more people would do this when they get new gear, its helpful to those trying to decide what to buy and who to buy it from.

#5 Gastrol

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Posted 07 December 2012 - 01:46 PM

Yes, very nice review!

#6 ryderc1

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Posted 07 December 2012 - 02:01 PM

I received my 8" STS from Rob about 15 months ago. I wanted a no compromise 8" scope and feel that I received one. Views have been superb when seeing conditions have cooperated and the scope is easy for me to handle and comfortable to use. Rob was great to work with and provided photo updates throughout the build process. As a result, I can highly recommend Rob's STS series.

#7 City Kid

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Posted 07 December 2012 - 03:20 PM

Nice review. I agree that Rob is great to work with. I have a brand new Teeter 12.5" Classic that I haven't really had an opportunity to put through it's paces yet but I hope to real soon. I'll be posting pictures and a report soon.

#8 coopman

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Posted 07 December 2012 - 03:33 PM

Thanks for the nice report on your 11STS.

#9 Busguy

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Posted 07 December 2012 - 03:36 PM

Thank you for your write up. I'm in the production queue and your review gives me a warm fuzzy. My primary is by Waite as well.

#10 bsim

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Posted 07 December 2012 - 05:03 PM

Don't worry about the Gordon Waite mirrors. Gordon makes great mirrors. I had mine independently tested by OMI and was quite satisfied with the result: Strehl Ratio of 0.97. I know another Waite mirror (18" F/4) was tested by OMI and it too had a Strehl Ratio of 0.97. I know it's heresy to say this: Gordon doesn't have the name recognition of Zambuto, but I've observed through enough Waite and Zambuto mirrors to say that Gordon gives Zambuto a run for his money.

#11 GeneT

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Posted 07 December 2012 - 10:24 PM

I would trust Rob. I spent fifty years of my life figuring out whom to trust in high-risk situations, in the mountains and elsewhere, and I think I’m fairly good at it. I would trust what Rob says about the new mirrors he offers.


Trust is the key, especially in a situation where you want good optics and construction of a telescope. I was surprised with your description of how loud the cooling fan was.

#12 mountain monk

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Posted 08 December 2012 - 12:50 AM

Gene,

I was surprised too. But, several points...

1. I am a lone wolf observer. On the few occasions when I am around other astronomers here I notice they all seem to have SCTs of various kinds. So it is not as though I can walk around comparing the fans of a group of Dob owners. As you know, most of Rob's larger scopes have two fans, and I've never heard anyone complain about the noise. My expectations may simply be way off.

2. A product of aging, I suppose, but I seem overly sensitive to sounds. We live in comparative isolation--we have to walk around to see any light and the only sounds we hear at night are occasional planes, the river, two miles away, and the wind in the trees. That great silence has spoiled me.

I did not wish to come across as disparaging. As I said several times--I am very pleased with the scope.

Enjoy the night sky.

Jack

#13 coopman

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Posted 08 December 2012 - 08:39 AM

It is probably a high capacity fan that is meant to be turned on for 30 minutes or so for the cooldown to be achieved and then shut off.
I can't hear the fan on my GSO Dob running, so sometimes I wonder if it is still running, and I always wish that it moved more air than it does.

#14 City Kid

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Posted 08 December 2012 - 11:03 AM

I was surprised with your description of how loud the cooling fan was.


I'm a little surprised as well. My new Teeter scope has three fans on it and they are all silent.

#15 Mike B

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Posted 08 December 2012 - 12:21 PM

...but I seem overly sensitive to sounds.

I wondered if something like that might be at work. Even living in a quiet town, with a new :ranting: boulevard :vomit: right behind us, when i turn my Dob's fan off while observing (rarely do ;)) its hum (now absent) looms loud in my ears!
:grin:

Still, its benefits far outweigh its "noise"... :shrug: Still, i wouldn't complain if it were quieter.

#16 mountain monk

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Posted 08 December 2012 - 02:28 PM

All,

Thanks for the helpful comments. As I mentioned, I had nothing to compare the fan too. I think this is a happy example of how isolated astronomers benefit from CN. I will contact Rob.

Mike: Is it a malady recognized by doctors? Too much gunfire? I've always been a bit weird about sound: I've never owned a TV; I go to cities once a year now, at most; I can't tolerate airports; and the music at my stepson's wedding last summer left me discombobulated for a week. (Not to mention all those leggy ladies dancing like crazed zombies under the stars. I appears the pagans won!) The silence of the night sky is one of my greatest consolations. Try as I might, I cannot comprehend folks listening to music while they observe. So yeah, the cooling fan is a problem for me.

Enjoy the night sky.

Jack

#17 Mike B

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Posted 08 December 2012 - 03:32 PM

I go to cities once a year now, at most; I can't tolerate airports; and the music at my stepson's wedding last summer left me discombobulated for a week. (Not to mention all those leggy ladies dancing like crazed zombies under the stars. I appears the pagans won!)

Totally with you there. I did the "city thing" as a commute for over 20 years... been out of that scene for 2-1/2 years now, being "reinvented" by the new economy. Now when i drive there, i feel like i've beamed down to the wrong planet. Yeah, they won... now they're after assimilation. :noway:


Try as I might, I cannot comprehend folks listening to music while they observe.


I *sometimes* do that- with a portable stereo, playing contemplative stuff, and quietly... sittin' off to the side somewhere, accompanying the crickets. Yet even that rarely... mostly i enjoy the natural sounds of the nite. It's good enough for my dogs, and they're good enough for me. ;)

Stickin' a loudspeaker in my ear, hooked to some 'puter by a wire... uh-uhh. :ohgeeze: I don't get that at all. But i s'pose we all have our thresholds. :shrug:

All this talk of noisy fans- it's given me an idea! :idea: Gonna try a *new* method of attaching my Dob's fan. Will report here if it helps.

#18 Starman1

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Posted 08 December 2012 - 06:36 PM

I was surprised with your description of how loud the cooling fan was.


I'm a little surprised as well. My new Teeter scope has three fans on it and they are all silent.

Silent? You must observe in a noisy environment. I can hear the fans 20' away, and even when I turn the cross fans off, so the low output rear fan is the only one operating, I can still hear that fan running. I do ignore it, but if I turn it off, the silence is palpable.
As fans go, they're relatively quiet. I've had other scopes with fans, and they were equally as noisy but with lower output. So, from that standpoint, the fans on my Teeter are relatively quiet.
But if I had them in my media room while I was watching TV, I'd have to turn the TV up to hear speech over the sound of the fans.
They cool the mirror quickly, but not silently.

Now if you have them wired into a potentiometer, and you turn them down, they can be very quiet. I always run mine unrestrained at a full 12V.

#19 City Kid

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Posted 09 December 2012 - 08:45 AM

I guess my backyard would be considered a noisy environment and that's the only place I've had the scope out so far. However it may have more to do with me being very hard of hearing than anything. Heck, maybe I was just too excited about my new scope to even pay attention to noise from the fans. I'm curious enough now that the next time I go out I'm going to specifically listen for the fans.






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