[Thomas Scherrer] has an odd piece of vintage test equipment in his most recent video. An AIM LCR Databridge 401. What’s a databridge? We assume it was a play on words of an LCR bridge with a digital output. Maybe. You can see a teardown in the video below.
Inside the box is a vintage 1983 Z80 CPU with all the extra pieces. The device autoranges, at least it seems as much. However, the unit locks up when you use the Bias button, but it isn’t clear if that’s a fault or if it is just waiting for something to happen.
The teardown starts at about six minutes in. Inside is a very large PCB. The board is soldermasked and looks good, but the traces are clearly set by a not-so-steady hand. In addition to AIM, Racal Dana sold this device as a model 9341. The service manual for that unit is floating around, although we weren’t able to download it due to a server issue. A search could probably turn up copies.
From the service manual, it looks like the CPU doesn’t do much of the actual measurement work. There are plenty of other chips and a fast crystal that work together and feed an analog-to-digital converter.
LCR meters used to be somewhat exotic, but are now fairly common. It used to be common to measure reactance using a grid dip meter.
I had to look up what “LCR” stood for. I probably could have eventually guessed, but the context of the article was, for me, a bit off.
Not sure what to say to that, LCR refers to the most basic elements of electronics, L inductance, C capacitance and R resistance and the article seemed fine to me.
yeah i immedately knew exactly what LCR stood for when i read the headline, but when i read the article it felt at first like i was in a different world. it’s because the headline was a question and the first paragraph didn’t answer it :)
Takes me back 20 years to when I used to have one of these in the lab. Was a big thing, but got the job done. I remember it worked well on the bench, as sorting and measuring parts was easy and you could use the devices top for sorting etc.
We have a big old Hewlett Packard LCR meter from this era and we have spent 20x its original (high) purchase price on getting it calibrated yearly, because that’s a non-trivial process and cost. They’re complex machines.
Before 90s, when cheap-ish o’scopes started to be available for mundane hillbillies like me here in the CZ, the GDOs were a tool of choice for majority of both professional and amateur repairmen and tinkerers. Easy to build, readily available and although not a total panacea, it was pretty useful bit of kit. Nobody needed digital connected LCR bridges apart from science and military labs. A 6F32, handful of passives, beeswax potted coils and Gustáv Husák was your uncle. Those were the days…