|
Peter,
Great set-up!
I have and use the SM60 pair as a double stack on an ED80.
Reading your write-up I have to disagree with the method of tuning...
Each etalon must be tuned off band but in DIFFERENT directions ie one slightly towards the blue the other towards the red - this gives maximum resolution and minimum band width. When properly tuned the peak intensity should be about 50% of that with a single etalon.
I've just gone through the "tuning" process with a 60mm Lunt DS and the difference was noticeable (unfortunately the "deadband" on the internal etalon makes the jobs doublely difficult.)
The attached sketch shows what we are trying to achieve.
(I also show my "patented" Vegemite DS controller! and a method of using the PST etalon as a double stack)
|