Quote Originally Posted by George Nova Scotia View Post

I think this gives us few options:

1) Find a source of the 15x30x2 glass from old stock
2) Find someone to make the required glass (with a min order less than 1000sq meters!)
3) Rig another piece of glass to the metal frame
4) find and buy another head.
5) operate without the HA glass and hope the Dichro filter holds up.

I got lucky and did #4 although I'd like to fix up the broken head I have.
Number 1 is looking very remote right now, after all it's been long time since these were made (10 years ?).
3,5 might be doable but results will vary - as they say.

the search continues,

I think option #3 is the most realistic. I saw your photo of the round omega glass - I'm sure some sort of fastener could be devised to hold it slung under the original HA glass location. Even a loose piece of oversize HA glass slipped between the lamp and the dichroics (not attached) might be workable.

Option #4 is a good idea in general. You never know when the gremlins are going to hit...it is always good to have a backup. The problem is that 2nd hand units are getting harder and harder to find. Several years ago they popped up on ebay at a fairly regular clip - now they are few and far between. To make things worse, the prices of 2nd hand 500 systems seem to have been climbing quite a bit as of late.

Option #5 - It might work, but I don't want to be the one to sacrifice the dichroics in my 500h to find out