Have been a little hectic.
In addition to trying to make some long overdue progress on my DMLS work, The Public Radio is kind of heating up right now. We received a new batch of PCBs, and got a few of them built up quickly.
To our astonishment, the first board we built worked immediately. This was actually kind of weird - we were expecting at least a bridge or two would need to be fixed, and there was always the chance that we had made a design error. Having our first board turn right on, and then quickly tune to WBGO 88.3, was a real kick.
Things won't always go so well, though, and so the following day we spent a bit of time straightening the workshop and setting up a bit of new tooling. The Public Radio HQ is now the home to a brand-old 1984 Tektronix 2465, a 4-channel 300MHz analog scope. We also picked up an inexpensive hot air rework station, and I dumped some bike parts out of one of my small parts cabinets and dragged it in to the city as well.
We don't have stencils for these boards (aligning circular stencils requires a bit more foresight than we could muster when we made the purchase) so we're laying out solder paste by hand with a syringe and toothpicks. Then we laid out a big piece of card stock and placed SMT components out part by part and set out with tweezers and loupes to place them on boards.
Our boards have two fine-pitch parts on them (the FM IC and the amplifier), and then they're almost all 0603 packages. These are manageable once you get going, but initially they're just fucking small. Anything smaller and we'd have a really hard time hand assembling these boards.
There are a few small modifications that we'll make before we go into production. Our thru hole trimpot's package needs to be changed, and we need to do a little tweaking on the gain setting resistors going into the amplifier, and I want to spend a little while getting graphics on the silkscreen layers. But these are minor changes; overall, the boards are 95% there.
On Monday we'll be receiving a batch of lasercut stainless steel lids, and we'll finally see how our whole assembly fits together IRL.