Hello,
Is there a link where I can see graphically how to change an ITF with rust in a PST 40?
Thanks.
Nebu.
Change an ITF in PST
- Montana
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Re: Change an ITF in PST
There is an ongoing thread on Stargazers Lounge might help at the moment, it hasn't come to the conclusion yet https://stargazerslounge.com/topic/3565 ... it-lasted/
Alexandra
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Re: Change an ITF in PST
Thank you very much Montana for your comments, I know this thread and it seems very interesting, the problem I see is that there are no photographs that explain step by step how to change the filter...
Cheers,
Nebu.
Cheers,
Nebu.
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Re: Change an ITF in PST
Hi Nebu,
It's actually very simple. It's very obvious when you look at it. The holes in discs are to turn them. The notches in rings are to turn them. Really all there is to it. The only thing about any PST is each section generally is glued/siliconed/something so it doesn't open easy and you have to use heat and a pipe strap wrench to turn things to avoid marring it up.
On a newer PST with an ITF it will be in the 2nd section of the eyepiece holder stalk. You will need to unthread it completely from the black box. And then separate it from the top section of the eyepiece holder, which has the small 5mm blocking filter you're used to seeing. Between the two is a threaded disc that shows a new filter, it's 12mm, and it will look cloudy and/or corroded. There is an obvious retainer ring that threads down onto the filter. It does not sit flush, it has tilt on purpose. You may have to break some silicone/glue of some kind to get it to turn, it will be obvious. I scraped the glue off with a small pin. It unthreads easy with any small instrument that can fit into the two notches on the retainer ring. Once exposed, you can drop the filter out. Then to replace it with your new ITF, put it in the same spot correctly oriented (Beloptik gives instructions, which color faces which direction). Then thread the retainer ring back down gently, don't over-tighten. Thread back on the other eyepiece holder section and thread the whole thing back to the black box.
Very best,
It's actually very simple. It's very obvious when you look at it. The holes in discs are to turn them. The notches in rings are to turn them. Really all there is to it. The only thing about any PST is each section generally is glued/siliconed/something so it doesn't open easy and you have to use heat and a pipe strap wrench to turn things to avoid marring it up.
On a newer PST with an ITF it will be in the 2nd section of the eyepiece holder stalk. You will need to unthread it completely from the black box. And then separate it from the top section of the eyepiece holder, which has the small 5mm blocking filter you're used to seeing. Between the two is a threaded disc that shows a new filter, it's 12mm, and it will look cloudy and/or corroded. There is an obvious retainer ring that threads down onto the filter. It does not sit flush, it has tilt on purpose. You may have to break some silicone/glue of some kind to get it to turn, it will be obvious. I scraped the glue off with a small pin. It unthreads easy with any small instrument that can fit into the two notches on the retainer ring. Once exposed, you can drop the filter out. Then to replace it with your new ITF, put it in the same spot correctly oriented (Beloptik gives instructions, which color faces which direction). Then thread the retainer ring back down gently, don't over-tighten. Thread back on the other eyepiece holder section and thread the whole thing back to the black box.
Very best,