Search found 3263 matches

by Merlin66
Sun Jul 14, 2019 5:06 pm
Forum: Solar Scope Modifications
Topic: Planning my first PST mod and need some help
Replies: 38
Views: 973

Re: Planning my first PST mod and need some help

The front AOK adaptor is just a means of mounting the PST etalon to the donor scope.
The rear adaptor will need addition spacers to bring the the final focus to a position 200mm behind the PST etalon assembly.
by Merlin66
Sat Jul 13, 2019 4:27 pm
Forum: Solar Scope Modifications
Topic: Planning my first PST mod and need some help
Replies: 38
Views: 973

Re: Planning my first PST mod and need some help

The most successful and probably easiest PST mods are where the donor OTA is adapted (focuser removed and OTA cut) to correctly position the PST etalon assembly at the design -200mm inside the prime focus.
Many other options are fraught with problems and difficulties.
Keep it simple, and safe.
by Merlin66
Wed Jul 10, 2019 7:17 pm
Forum: Solar Scope Modifications
Topic: Planning my first PST mod and need some help
Replies: 38
Views: 973

Re: Planning my first PST mod and need some help

As well as the above important comment from Mark, remember you don’t need a focuser in front of the PST etalon. Once the etalon is correctly positioned at the -200mm in front of the prime focus it should not be moved. Any focusing behind the etalon to accommodate the eyepiece/ camera can be achieved...
by Merlin66
Sat Jul 06, 2019 6:11 pm
Forum: Solar Scope Modifications
Topic: Planning my first PST mod and need some help
Replies: 38
Views: 973

Re: Planning my first PST mod and need some help

I think you need to review the basics of the PST mod. 1. The front of the etalon must be positioned near as possible at -200mm inside the prime focus of the donor scope. 2. The final focus will then be very (very) close to 200mm behind the etalon assembly. Check your fitting/ settings to see how clo...
by Merlin66
Thu Jun 27, 2019 10:21 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: question on Young's F line image
Replies: 4
Views: 148

Re: question on Young's F line image

Nothing as distinct as Young shows.
We may have to wait until we see more activity.....
by Merlin66
Thu Jun 27, 2019 8:24 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: question on Young's F line image
Replies: 4
Views: 148

Re: question on Young's F line image

I simplistically think in terms of Severny’s moustaches as described and shown on p 82 and p83.
by Merlin66
Thu Jun 27, 2019 7:38 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: question on Young's F line image
Replies: 4
Views: 148

Re: question on Young's F line image

These were distortions seen in the Spectral line. A fine slit positioned over an active area.
See recent discussions and links from Peter Z.
by Merlin66
Mon Jun 24, 2019 12:19 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: A 19th century PST
Replies: 5
Views: 137

Re: A 19th century PST

I have some illustrations back home..... Basically a multi prism spectroscope with adjustable slit mounted on an excentric rotating adaptor which fitted the telescope. The adaptor could be rotated to bring the slit onto the edge of the Sun and when proms were found, the slit opened to allow a full v...
by Merlin66
Sat Jun 22, 2019 3:08 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: A 19th century PST
Replies: 5
Views: 137

Re: A 19th century PST

Browning made many solar spectroscopes which could be mounted on any refractor to allow observation of the proms using Huggin’s method.
More like a Quark than a pst.
by Merlin66
Thu Jun 06, 2019 1:06 pm
Forum: Solar Scope Modifications
Topic: How do I know my Stage 2 is 200mm?
Replies: 5
Views: 163

Re: How do I know my Stage 2 is 200mm?

The distance from the rear lens of the etalon assembly to the focus should be very close to the Majic 200mm.
It’s probably easier in some cases the find the prime focus position of the donor scope and then position the front element of the etalon assembly at -200mm by measurement.
by Merlin66
Sat Apr 27, 2019 10:25 am
Forum: Solar Scope Modifications
Topic: help with stuck threads
Replies: 11
Views: 406

Re: help with stuck threads

Brian,
Not sure I can help at this stage.....
I’ve successfully use a smear of boot polish on all the treads before using them, It’s worked well for me for over ten years.
by Merlin66
Wed Apr 17, 2019 11:28 pm
Forum: This is SolarChat !!
Topic: I need a laptop that matches the speed of ZWO ASI174
Replies: 10
Views: 419

Re: I need a laptop that matches the speed of ZWO ASI174

Bart,
I should have said my ol' ACER didn't have USB3 ports.......
by Merlin66
Wed Apr 17, 2019 4:40 am
Forum: This is SolarChat !!
Topic: I need a laptop that matches the speed of ZWO ASI174
Replies: 10
Views: 419

Re: I need a laptop that matches the speed of ZWO ASI174

I had similar concerns with my ACER....
Bit the bullet and went for a MSI gaming machine,i7, 16Gb memory, USB3, 500 Gb SSD and 1 Tb data drive.
Handles my ASI 174 and ASI 1600 at max frame rate.
Recommended.
by Merlin66
Fri Apr 12, 2019 11:57 pm
Forum: Solar Scope Modifications
Topic: Tilt needed on a front ERF?
Replies: 2
Views: 307

Re: Tilt needed on a front ERF?

I mount the D-ERF with a 1 -1.5mm tilt.
That's usually enough to prevent issues.....
by Merlin66
Wed Apr 10, 2019 12:49 am
Forum: Solar Scope Modifications
Topic: Planning my first PST mod and need some help
Replies: 38
Views: 973

Re: Planning my first PST mod and need some help

Mauro, I have a write up available for the PST mod drop me an email address for a copy. A couple of critical things. The etalon assembly must be positioned 200mm inside focus. The etalon works in an f10 beam. If the donor scope is faster (f5) the aperture will be reduced. Adaptors, front and rear ar...
by Merlin66
Mon Apr 08, 2019 6:54 am
Forum: Solar Scope Modifications
Topic: Crazy Idea...?
Replies: 4
Views: 363

Re: Crazy Idea...?

Bob,
I like the idea!
Not sure how you would control/ achieve the nominal separation (gap) and maintain it...Temperature control is one avenue.....
by Merlin66
Tue Apr 02, 2019 1:54 am
Forum: Solar Scope Modifications
Topic: 150 mm Solar Newton
Replies: 50
Views: 1965

Re: 150 mm Solar Newton

First light is always exciting!!
Well done for getting reasonable result.
Onwards and upwards.
by Merlin66
Mon Apr 01, 2019 4:16 am
Forum: This is SolarChat !!
Topic: SPICULAES by PROs
Replies: 8
Views: 401

Re: SPICULAES by PROs

Valery,
One issue it the ability to accurately tune the filter into the wings, at known and repeatable wavelength off set.
With a Spectroheliograph this is much easier and more accurate.
by Merlin66
Thu Mar 28, 2019 10:43 pm
Forum: This is SolarChat !!
Topic: OT - March 2018 S&T wanted
Replies: 3
Views: 202

Re: OT - March 2018 S&T wanted

Franco,
Many thanks. PM sent.
by Merlin66
Wed Mar 27, 2019 10:37 pm
Forum: This is SolarChat !!
Topic: OT - March 2018 S&T wanted
Replies: 3
Views: 202

OT - March 2018 S&T wanted

Seeking some help.
I've been collecting S&T for many years and now have them back to Vol 1, #1
For some reason, MARCH 2018 issue appears to be missing......
I'm looking for a clean, complete copy.
If you can assist let me know.
Many thanks,
ken
100_3560.JPG
100_3560.JPG (111.74 KiB) Viewed 202 times
by Merlin66
Mon Mar 25, 2019 4:14 am
Forum: This is SolarChat !!
Topic: More aperture please (PST)
Replies: 19
Views: 876

Re: More aperture please (PST)

Christopher,
You seem to have ended up with distinct banding across the whole disk????
by Merlin66
Mon Mar 25, 2019 4:10 am
Forum: Solar Software
Topic: New version of ImPPG
Replies: 6
Views: 380

Re: New version of ImPPG

Alexandra,
Just downloaded the latest version and it works OK for me...
Video settings??
by Merlin66
Sun Mar 10, 2019 9:12 pm
Forum: Solar Scope Modifications
Topic: PST Mod Reflections back off the Blocking Filter
Replies: 17
Views: 974

Re: PST Mod Reflections back off the Blocking Filter

Andrew, The pins are still there but just run on the interior surface of the housing. The prism is held by the focussing screw and the size of the block used. All the PST’s as far as I know were assembled in Mexico. Due to warranty returns etc etc there’s no meaningful relation between the serial an...
by Merlin66
Sun Mar 10, 2019 6:37 am
Forum: This is SolarChat !!
Topic: Were to put uv/ir filter?
Replies: 6
Views: 263

Re: Were to put uv/ir filter?

More important than the UV-IR is the mandatory ND3 filter.
You can fit an UV-IR after the ND3 if you feel concerned.
by Merlin66
Sat Mar 09, 2019 10:52 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New PST ITF?
Replies: 33
Views: 4501

Re: New PST ITF?

The angled thread is to give a slight tilt to the ITF filter.....