Coronado PST front element replacement question

[AstroFlyer]

Does anyone know if an old "rusted" PST lens can be replaced with the new clear blue one?
Does anything else need to be modified or is it just straight swap?
Thanks.

Arek

[Merlin66]

Yes.
I've done this change over for a mate.
I purchased a gold tube/ blue objective from a guy who had modded his PST.
Just screwed onto the Black box..focus was OK, but because the secondary filter is now missing the Ha image is brighter.

( The Blue objective PST has a second UV-IR filter in the eyepiece holder to reduce the energy on the final blocking filter...the blocking filter still gives a 100% safe image.)

Ken

[AstroFlyer]

Excellent news Ken.
Thanks for a quick reply.
Inspired by your posts from few years ago I'm looking at building EC90 down the track...


Arek