Is my Coronado PST faulty?

[lukebl]

I got out my old Coronado PST today, even though the sun is very quiet, to test it out and I noticed that the view was incredibly faint. Too faint to see anything at all really.

Could the ITF filter be the fault, as that seems to be the usual problem with PTSs? The pictures of rusty ITFs I've seen on the web show the filter looking very uneven at the periphery. However, mine looks fairly even right across as this photo shows. Perhaps the filter is so corroded that the corrosion has spread right across the filter?  I haven't had it out for at least 18 months.

Any ideas? I was thinking it wouldn't be worth fixing, but I've just checked the current price online, and maybe it's worth replacing the filter after all.

[JamesF]

If it does need fixing then the alternative to replacing the filter is to go for the full fat mod and use a separate ERF in a larger aperture OTA.

James

[Peter Drew]

Looks like a complete failure to me, still safe but needs replacing to restore the performance.  As JamesF says, golden opportunity to upgrade to a PST mod.    😃 

[lukebl]

11 hours ago, JamesF said:

If it does need fixing then the alternative to replacing the filter is to go for the full fat mod and use a separate ERF in a larger aperture OTA.

Thanks for the input gents.

That's interesting as I already have an ERF from an incompleted PST mod with a TAL 100RS which I was never happy with. I'll have a go at  rebuilding it, although I always liked the wider full-disc view that the the basic PST gives.

[Merlin66]

Luke,

you can easily replace the defective ITF in the PST with a Maier filter.

Probably around us $100.