The Ware for December 2022 is shown below.
Turning this into a suitable Name that Ware-style entry was a bit tough, but I think maybe I hit a balance between leaving enough clues, and giving it away. We’ll see shortly!
I have a lot more to say about this ware: I will give proper attribution once the ware has been guessed (or the end of the month, whichever is sooner); but let’s just say I was incredibly pleased to find such detailed images in the public domain.
The ware for November 2022 is a Keithley 2110-240. I’ll give Rodrigo F. the win, but I’m curious how he knew it was the -240 version; I did not expect someone to discern the line voltage rating from the photos!
Also, thank you Ian Mason for the lucid explanation of the exposed traces near key signals. Here’s his quoted answer, so you don’t have to look it up in the comment thread:
The reason for stripping resist from over guard rings [is] to ensure that any leakage paths come into electrical contact with the guard ring. If you had, say, a bit of flux residue as a leakage path, if it passed between two pins but over the solder mask then the guard ring would be insulated from it and would have no effect. The whole point of a guard ring is that it’s a (relatively) low impedance path either to ground or to a duplicate of the measured signal – being insulated behind soldermask is anything but low impedance.
It’s tricks like these they never teach you in school. I’m guessing it was a hard-learned lesson for the persons who had to figure out that trick on their own. Thanks for sharing the knowledge!
Edit: I forgot to note that Rodrigo F. should email me to claim the prize!
The Ware for November 2022 is shown below.
A grounded guard ring is placed around some of the most sensitive analog traces; I would love it if someone could teach me why the soldermask is removed for these guard rings. I imagine there must be some motivation to retain this motif even into mass production, since the mask-less traces run between SMT pins, which I have to imagine incurs a potential yield impact, or at the very least it makes rework more challenging.
Also, yet another tamper-proof seal broken:
It was just a matter of time…such is the fate of any seal within my reach!
The Ware for October 2022 is a Wavetek Model 21 signal generator. The winner is Marc! Congrats, email me for your prize!
Here’s some more photos of the system for context. It consists of a function generator (analog) board, and a digital control board, along with a third board (not shown) that manages the LCD and buttons.
The Ware for October 2022 is shown below.
I think there should be ample clues in the first picture to guess the ware, but I included a couple of close-ups of the circuits because I love it when circuit boards document their functions so clearly. You can basically read the schematic directly off the traces. I also enjoy the motif of “here’s a ROM but no microprocessor” (the ROM is the ceramic-packaged 2716 in the top right of the first photo, with the label covering the UV erase window). ROM-based sequencers/FSMs and lookup tables were fairly common for this vintage, but these days most designs use ROMs exclusively to store code that is accessed by a CPU.