PST

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Post Reply
User avatar
rsfoto
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6163
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México
Has thanked: 9412 times
Been thanked: 5574 times

PST

Post by rsfoto »

Hi,

I am at the moment talking with a Science and Art Museum here in Mexico for new equipment for their Astronomical Observatory.

They will do Sun observation in white light and H-Alpha.

After reading a lot here, I would like to ask if the rear part of an PST could be used instead of buying a new BF30. The front part of their PST is totally blind or oxidized as we say here in Mexico.

They already have a Solarmax 60 but for remote operation the focusing is very difficult so I want to use the front part and add a BF30 on a separate telescope. In this case we are talking about a Takahashi Sky 90.

Is any part of the damaged PST is reusable I would make custom adapters for the reusable parts and save the money for the planned BF30.

I hope you understand my question.


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
User avatar
rsfoto
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6163
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México
Has thanked: 9412 times
Been thanked: 5574 times

Re: PST

Post by rsfoto »

Another question.

¿ Where is the BF in the PST ? and can it be taken out in order to use it in straight mode ?

Thanks


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: PST

Post by Merlin66 »

Rainer,
A "blind" PST can be used successfully in a PST Mod.
Confirm your email address to me and I'll send a copy of the PST Mod write-up.
The etalon and the "black box" can be used as a Stage 1 mod.
You need to be able to position the etalon at 200mm inside prime focus - this may be difficult with your scope without cutting the OTA!
Also you'll need a D-ERF mounted at the objective.
The blocking filter in the PST is in the eyepiece holder (the small red filter visible when you look down into the eyepiece holder) It's only 5mm diameter. It can be removed (the whole top section of the eyepiece holder) and re-fitted to a diagonal or suitable spacer tube.
IMHO it's a marginal proposition. Getting a BF10 (or larger) is the way to go.
Hope this helps.


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
User avatar
rsfoto
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6163
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México
Has thanked: 9412 times
Been thanked: 5574 times

Re: PST

Post by rsfoto »

rsfoto at rsfotografia dot com

Thanks :thanx:


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
peter drew

Re: PST

Post by peter drew »

Before I knew any better, my first PST mod was using a Sky 90. To avoid cutting the tube, I removed the whole focuser and made an insert to attach the PST body to the Sky 90 tube. Focusing was by the usual PST method. The 5mm blocking filter was not much of an issue due to the short focal length. I now know that this mod was restricted to F10 by the etalon giving an effective aperture of 56mm, it was still a considerable improvement over the original. There are better and cheaper donor options for the PST than a Sky 90.


User avatar
rsfoto
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6163
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México
Has thanked: 9412 times
Been thanked: 5574 times

Re: PST

Post by rsfoto »

Hi Ken and Peter,

Thanks for the comments. As you know those institutions are not blessed with big funds and I am analyzing all possibilities in order to save some bucks. If it is not feasable or it does nor make sense then I will follow the planned route wirh the SM60 front Etalon and the BF30 we already have in the budget mounted on a SKY 90.

The whole setup will be remotely controlled from an adjacent office and the Sun images in H-alpha and White light will be projected on MOntiors in the publich area so the people do really see somthing.

Nowadays they are looking through the eyepeice but we all know that without a bit of experience 50% of the ibservers see = Nothing :S

I did choose Takakhashi telescopes as I know them very well, they have good rack and pinion focusers and I know they do survive harsh environments. The rack and Pinion focusers do have a very good foscuing point repeatability in repositiong of a saved focus point. ITakahashi scopes are not cheap but they are really worth their money.

I know there are cheaper scopes outside but mainly they do all ahve crayford focusers and for me the crayford focuser is moire a disease then a real focusing option.

Also the museum can not invest every year in new telescopes.

It is a challenging project :whistle:


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
Post Reply