Second Attempt (electronics only): Better, Still Mylar/Black Only

(The photos of internal workings in the gallery are of the second attempt PTR Module)

So, using some lessons from the first build, I built another, using a mask made of  copper PCB material drilled out for the optos. I also considerably thinned the guide slot by using 0.015" PCB material and the double-sided Apple tape. On this unit, this mounts to the LED board, making assembly/modification much easier. After a few weird component issues (an LM117-3.3 putting out 4 volts and a dead opto, easily found with the test tape and program) this worked better. I still made the 1.000 slot for the paper tape a bit too wide; I corrected this with "cat whiskers" on either side of the slot made of resistor trimmings to fine-guide the tape. This worked VERY well, with no "cross-talk" or show-through problems. But....I still can get good reads only from Mylar or black tape. I suspect that I will have to use op-amp comparators or something like that in attempt #3.  Still, this electronics module is a good build and I will probably use it with an 8080 emulator project.