I received a test source of electroluminescent panels for the T4 build yesterday, General Electric night lights. Now, if I can source some GE resistors this thing will be 100% same source! Hahahaha, just kidding. These night lights were made in China, so the only same in the source is the name.

Plugged it in and it fired right up, I was so excited I forgot to take a picture, sorry.

Disassembly is pretty easy, there's already a groove where the front and back case half meet. It was just a matter of running a knife around the groove until I could shear the three connection pins, then it opened right up. What you see is what you get, the two contact pads at top of the element are press fit to the metal studs in the back half of the enclosure which taper into the blades of the plug. 120 volts AC (in my neck of the woods) right across the element, it's that simple.

My initial hope was to cut the element down so it could lay directly atop the CdS cells which would be pointing "up" in relation to the octal plug base. However, it appears that one electrode runs the perimeter of the field and to cut it down at all would sever that conductor and potentially render the panel useless. Being that this entire assembly is built on something like acetate, there is flexibility, so my current line of thinking is to roll this like a tube to line the inside of the can and situate the CdS cells in a periscope type fashion.

Received my General Electric B-46 photoconductive cells yesterday. After struggling with the 40 year old blister pack I stuck this part across the leads of a meter..

1.26-1.71 K under ambient light in the living room (no idea what angstrom I'm working with) and 160-200K after 5 seconds of cover, which puts it right in line with the Clairex CL505L that is the heart of the early T4 optos.

13th week of 1969 would be my guess. With the octet I concluded hastily that, should all fall within spec I can roll four T4 clones; I'm now leaning on slapping a range similar modern CdS cell to drive the meter, since that leg is out of the audio path and there is no benefit to a period correct part there. I tend to ignore what the meter is doing anyway..

Now to source the electroluminescent part, I'm pretty sure I can find a 2.2 meg resistor in a bin. There's also the matter of enclosure, but I do have some things I can cannibalize.