Quote Originally Posted by Feign View Post
Unfortunately, this little revelation adds parts that need machining and I can't for the life of me figure out how you can get it so the end user can calibrate a multi-step attenuator easily, since you have to aim the laser exactly through both of the holes.
I'm showing my ignorance here, but... wouldn't it just be a matter of extra snap-together parts designed to hold the pre-machined parts in position? If the emitter is mounted to the circuit board then its position, along with all dimensions, are known quantities.

I realise there are plenty of fiddly, moving parts to calibrate, but wouldn't a static attenuator be easy enough to ensure consistent placement for?