Homebrew PCBs

Barry Demers <sdad@...> writes:
> Now, if you can dial in that closely then go for it.

Sure, just pick up a transmission step gauge and a timer.  I've got my
UV box down to exactly where the film says the exposure should be, and
I know how far over or under I can go and still get good results.

In my case, I have 8 steps of working range, or a 16x time difference
between "just enough" and "almost too much", which means a window from
1.4 minutes to 22 minutes (I use 5.5 minutes).

What I'd like is a box that can do both sides in less time, which
means *more* UV.  If you need 24 minutes with a 15 watt bulb, then I'd
need four 30 watt bulbs - per side - to improve on my exposure times.