start MOD

[alessbonsai]

To start a MOD where do I start..
Where can I find the info mod 1/2
I use a PST or a 50/60 LUNT
There is an optimal configuration

[marktownley]

What scope are you going to put it on?

[alessbonsai]

I would like to use an f/10 , I would like the 102 Tecnosky/TS or a telescope that I already have 80/f10 , modified several years ago for planets.

[alessbonsai]

this is the initial idea .. what am I going towards ? the lens in front of the etalon is a collimator / telecentric, I have to keep it, since I'm at f10

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[AndiesHandyHandies]

Hi

You need the first option with the collimating lens.

The lens needs to sit 200mm inside the focus point of the telescope. 20mm aperture x F10 = 200mm.

This can be a problem. You may have to cut the OTA shorter to get the lens in the right place.

For my Maksutov mods I removed the collimator lens from the PST body, simple unscrew the holder.
I placed it in a 1.25" barlow holder with the same 25.4mm size, USA product so 1" lens.

And use a 48mm to 28.5mm adapter to screw the lens on the appropriate extension tubes into.

It is important Pupak says to get the lens as close as possible to the 200mm inside focus point.

In my Maksutov I put 1.25" UV-IR and Baader 35nm after the lens as a ERF. Advantage is the reflections are expanded back out they way they came in so no hotspot.

At 80mm the PST Erf should do the job OK.

Cheers. Andrew.

[alessbonsai]

if i understand correctly i have to keep the first lens of the black box inside the 20cm plane of focus and instead of using a d-erf i can use baader uv/ir and ha filters to dissipate energy, i have these 2 inch filters with cell , the Ha filter is photographic narrow band. Can the filters be mounted close together or do I space them apart to avoid reflections? The Ha filter is a mirror on the outside

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[alessbonsai]

I can't find an adapter to connect the black box

[alessbonsai]

especially I can not disassemble the yellow tube

[marktownley]

You need to mount the filters as high in the light path as possible. I would get some spacing between them.

AOK swiss sell the adapters you need. There might even be one in the second hand section on here.

[AndiesHandyHandies]

Hi

PST mods are subject to reflections.

Off the tilted etalon and the 35nm.

The PST is designed to give a full h-alpha 'sweet spot' view for a 4mm sun. At a nice price. Like the 40mm Lunt.

Going to 80mm will reduce the sweet spot to half the diameter but the 5mm blocker will will vignette the sun anyway.

Using a PST Mod 2 with binocular viewers helps with the reflections and improves surface details which can be seen.

For a nicer 80mm mod better to use a 40mm Lunt etalon from their 'PST' competitor. Which you could later double stack.
For a 100mm mod use a Lunt 50mm etalon from their modular series. As big as you can practically go on good days.

Nice to have a play with the PST as a starter.

Cheers. Andrew.