DAVIDG
Carpal Tunnel
Reged: 12/02/04
Posts: 1985
Loc: Hockessin, De
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Both of my PST's (CaK and Ha) had astigmastism problems and both were traced to a misaligned penta prism. They have been repaired and the images quality has been GREATLY improved in both instruments. Owners of the both version should be checking their prisms also. It's pretty easy to test for astigmastism in a Ha unit. Use around a 15mm eyepiece so the Sun fills most of the field and as you focus the image look at the limbs of the Sun that are parallel to main body of the telescope. If one side comes to focus before the other then there is an issue. They both need to come to focus at exactly the same spot. It doesn't take much misaligned of the prism to start to wash out detail.
I thought that both my PSTs gave good images before the astigmastism was corrected, now that they are fixed, I see what I missing. The images are so much sharper.
- Dave
Quote:
Nick & Andy:
I guess I haven't been paying much attention to the CaK PSTs and the astigmatism problem evaded my notice! Thanks for the head's up!
My club has one of them but I haven't spent much time using it, my eyes just aren't very sensitive up at that color anymore so I can't see much. I'd have to have a chilled black bag (with vent holes so I can breathe) to put my head & the eyepiece into in order to use it much. It's a tough little scope...
Rich
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Homemade 'scopes 8"f/7,6" f/5", 6"f/4, 4.25" Schief. 60mm Coronagraph,60mm H-alpha system, 4.25" White-light Solar Newtonian,solar spectroscope, 4.5" f/16 Schupmann Medial refractor, 14 Stellafane awards 7 in optics
Engineering = Taking what you have and making what you need.
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darkstar528
Postmaster
Reged: 03/06/07
Posts: 6764
Loc: Hodgenville, Kentucky, USA
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THANK YOU!!!!!
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Blue skies,
Stephen "Darkstar" Ames
PST(#96038), VIXEN 8-24mm,CEMAX 2x Barlow, Thousand Oaks White Light Filter and a Meade Elec EP
CFI, CFII, MEI, working on EIEIO!
BAA Member
My solar site:
http://seemysunspot.com
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Dubboy
Carpal Tunnel
Reged: 07/05/05
Posts: 2254
Loc: Northern Michigan
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Quote:
THANK YOU!!!!!
Your welcome, Stephen...now, how about sending me some clear skies so I can get a look at our star!! 
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Don
"Don't worry about what telescope you own, or its quality. Just get out under the night sky and enjoy God's wondrous universe" Thomas Back.
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cocobolo
Carpal Tunnel
Reged: 10/27/07
Posts: 1550
Loc: british columbia, canada
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Dave, do you know if this misaligned penta prism problem is common at all? My PST has fairly recently had "the fix". Is it possible it might have been checked for misalignment do you know? It looks like more than a week of bad weather coming here so it will be some time before I can check. Thanks, Keith
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NickH
Post Laureate
Reged: 05/09/06
Posts: 3717
Loc: Wiltshire, UK (near StoneHenge...
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I think the astigmatism is a lot more common than people realise. If you are just viewing with the standard EP's most people won't to be honest notice it (I didn't) until I started imaging, and then at higher resolutions, the scopes simply would not focus. The prism is held in place by a simple glue, which looks like it can easily slip, plus if you rack the prism in and out of focus to the extremes, it can and does if not set properly, hit the metal sides, which can further misalign it (it did with my PST H-A)
It's a flaw in the prism design and mounting assembly, but one which can be fixed, and it now seems thankfully that Meade have recognised the issue, and are fixing scopes, after at first (and there are posts here which show this) denying the problem existed...
If in doubt, do what DavidG said, with the H-A version. Cak, you HAVE to stick a camera (toucam etc) on it, and ramp up the magnification (i.e put a 2X or 3x barlow in the imaging train). It is immediately obvious once you know what you are looking for. With my CaK, I genuinly thought the image was always a bit blurry, but put that down to the optics/CaK filter and how they work (I looked at Paris Meudon, and there non composited images looked the same). Then I saw what "could" be done with a CaK, and realised that there was a problem.
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cocobolo
Carpal Tunnel
Reged: 10/27/07
Posts: 1550
Loc: british columbia, canada
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Nick, that is just an excellent explanation. The only possible suitable camera I have is the little Orion Starshoot II which I have just got. Still in the box. I'll give that a go. Thanks, Keith
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ElWampa
newbie
Reged: 07/27/04
Posts: 3
Loc: Round Rock Texas
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Just obtained a PST from eBay today, it seems to have the sickness as well..
Here is an image I took right out of the box.
Might want to add #97193 to the list. Say it isn't so!?!
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"Quantum Mechanics: The Dreams Stuff is Made Of."
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NickH
Post Laureate
Reged: 05/09/06
Posts: 3717
Loc: Wiltshire, UK (near StoneHenge...
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Rusted like a goodun...
Oh dear!
I just picked up a Solarmax 40, with a very very very rusty BF10, which is now being looked in to ..
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astropup
sage
Reged: 12/12/05
Posts: 423
Loc: Ann Arbor, MI
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ElWampa,
I just sent you a PM. Check your "My Home" to read it.
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DBA Deep Space Observer 10" f/5 (GSO Dob)
Meade 114/500 4.5" f/8 Reflector
PST
Celestron Skymaster 15x70mm
Oberwerk 8x56mm
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DAVIDG
Carpal Tunnel
Reged: 12/02/04
Posts: 1985
Loc: Hockessin, De
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Quote:
Dave, do you know if this misaligned penta prism problem is common at all? My PST has fairly recently had "the fix". Is it possible it might have been checked for misalignment do you know? It looks like more than a week of bad weather coming here so it will be some time before I can check. Thanks, Keith
Keith,
My rust repaired PST had a misaligned prism after it was returned and when I checked my CaK it was also misaligned. I have sent pictures of my misaligned prisms to a couple of friends and they also reported that their prisms were not aligned correctly because the glue holding them allows them move after time. The astigmastism makes the image look alittle soft and you might think it's just bad seeing. If you never looked through a PST with a correctly aligned prism you most likely won't know you have a problem. We have all heard that some PSTs give better images then others. The thought is that this is just variablity in the quality of the optics or bandwidth of the Etalon. I think it's more of combination of the "rust" problem and a misaligned prism. I'm very pleased with the image quality that both my PSTs now produce. Before the rust was fixed and the prisms aligned I always thought that image could be sharper and I could see that the limbs of Sun on opposite sides were never both in sharp focus at the same time. Now that they are and the image is just sharp and seeing is less of issue.
- Dave
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Homemade 'scopes 8"f/7,6" f/5", 6"f/4, 4.25" Schief. 60mm Coronagraph,60mm H-alpha system, 4.25" White-light Solar Newtonian,solar spectroscope, 4.5" f/16 Schupmann Medial refractor, 14 Stellafane awards 7 in optics
Engineering = Taking what you have and making what you need.
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DanWray
newbie
Reged: 10/11/06
Posts: 4
Loc: Denver, CO, USA
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My PST #98457, got knocked over, was sent in for repairs, was lost, finally found, now blue and not as good as it was, disapointment. I also was using it with a bino viewer by removing the spacer under the eyepiece holder. I can no longer remove that piece because it now has a secondary filter in it. I am not happy but I don't know what to do.
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12.5" f6 newtonion homemade equtorial
100mm f6 BW Optic refractor Super Polaris mount
80mm f12.5 Pentax J-80 altaz refractor
75mm f16 Unitron 131-C folded equitorial refractor
60mm f15 Goto Hy-Score model 451 altaz refractor
60mm f15 Tasco 7 TE equitorial refractor
60mm f11.7 J.C. Penney equitorial refractor
PST
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NickH
Post Laureate
Reged: 05/09/06
Posts: 3717
Loc: Wiltshire, UK (near StoneHenge...
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I personally don't think the blue ones bandpass matches the old ones either. My old one, was 0.7A easily (I was able to a/b it against an SM40), but was rusty and astigmatic...the new one, has no rust, not quite sure on the astig front yet, but the bandpass is now worse..
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CtGuy1955
journeyman
Reged: 02/12/08
Posts: 8
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I went to the NewHavenAstro website and in the message area, they mentioned having to send two of the clubs PST's back
to be repaired. I thought how odd that two had to be fixed.
I Immediately went to a search engine and typed in PST
recall, and your site came up. I started to read about the
rust and viewing the pictures. Soooooooo, I went out to the
observatory and got the PST case out, and brought it into
the house. With much antisipation, I opened the case, pressed the two buttons on the lens cap, and behold....
Lots and lots of orange/brown RUST stuff. WOW
I called opt and they said it has a 5 year warrentee,
and they faxed my 11-29-04 sales slip to Meade.
I have to pay for shipping and insurance and send the
scope to meade. They said there is about a 4 week waiting
period. I also have to put a $15.00 check in with the scope
to cover the return to me.
I have heard that when I get my scope back, it will have
alot of new parts and look different. I really want to thank you so much for having such a great site that can help
people like me. I probebly wouldnt have noticed the problem,
and time would have run out. Funny thing to me is that Ive
heard that when I get my scope back, it will have a one year
warrentee. With the original 5 year, it should have until
11-29-09. I dont know how liable Meade is/was buying the
company, but I am glad they are doing something about it
and not just shunning the responsibility.
Please add the serial number of my PST to your list.
95660 Sick
Edited by CtGuy1955 (02/12/08 10:48 PM)
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cocobolo
Carpal Tunnel
Reged: 10/27/07
Posts: 1550
Loc: british columbia, canada
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Welcome to the solar forum CtGuy1955. We're all going to guess that you are around 53 y.o. Meade has been getting some good press on CN about the fix for the PST. I got mine off another CN chap, and he had it fixed. So far, it is performing very well so I have no complaints at all about the Meade/PST affair.
Most people are saying that it is taking a bit longer than 4 weeks, but you will essentially have a new scope when it comes back.
Again, welcome to CN and the solar forum. Keith
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CtGuy1955
journeyman
Reged: 02/12/08
Posts: 8
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Thank you Keith, for the nice welcome and support for
a problem that until this morning, I didnt even know
I had. You are correct, I am 53....are you psychic or
what? scary! I decided to buy the PST after trying
to view the sun with my LX200gps 10" with both a Mylar
type baeder paper and a darning frame, and another type
of sunglass type. It was ok. Getting the pst and seeing
the prominences was so kewl. Although I never saw anything
happening but on the edges, never anything happening inside
on the surface. Dont know if I should, but according to
the pictures on the box.....
I hope to be able to get the scope back and start taking
some photoes of our closest star.
Thanks Keith and clear Skys
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cocobolo
Carpal Tunnel
Reged: 10/27/07
Posts: 1550
Loc: british columbia, canada
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It may have been the rust problem that was degrading the images. But using a combination of the tuning ring and the focus knob, you can get the details on the disc to show up. Usually not at the same time though. And I find that if you centre the object of interest in the eyepiece that it shows up way better. That is to say, if you have a prom on one side of the disc, then center the prom, it is much clearer. We had a thread running about this a short while ago. You may be interested in going back over some of the solar threads to see the stuff that comes up. And as for some of the pictures - well, lots of these guys just blow your socks off. Hunt for a few of Pete Lawrence's pics using his PST. You won't believe what he does. Keith
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CtGuy1955
journeyman
Reged: 02/12/08
Posts: 8
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I cant believe some of the pictures Ive been seeing. I do
like the ones that people have used photoshop and blackened
out the Sun, so only the Prominences show up. I joined
the PST group on yahoo.com and uploaded some pictures of my
Rust problem. I mailed my pst to meade today. Cost me
20.85 snail mail with a 600 insurance and look up online
confirmation that they received it.
Here is a nice pic.....
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NickH
Post Laureate
Reged: 05/09/06
Posts: 3717
Loc: Wiltshire, UK (near StoneHenge...
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Wow, that one looks like pollen...
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Dubboy
Carpal Tunnel
Reged: 07/05/05
Posts: 2254
Loc: Northern Michigan
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YIKES 
Looks like a globular cluster got inside and flew apart! 
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Don
"Don't worry about what telescope you own, or its quality. Just get out under the night sky and enjoy God's wondrous universe" Thomas Back.
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CtGuy1955
journeyman
Reged: 02/12/08
Posts: 8
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Come on now guys, You wouldnt want me to have just a small
fringe of dust on the outside only? I needed to have it
all over, especially when I tilt it up towards sol, the diagonal in the back really gets coated nice so as to
better protect my eyes from the harmfull rays of the Sun.
I took one of the pictures I took of the sun that had some
small prominencies and was wondering how people "mask" the
photo, so that the sun is black, the sky is black, and just
the prominencies are a deep red color, and the picture looks
really kewl???? Thanks for advice (whoops, wrong thread)
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