Update on Analog Stuff (publ. 2025-02-21)

I'm still waiting to be able to make the parts order. I really need a multiplier now if I'm going to make further progress, due to the more interesting models I'm looking at.

Something that has been bothering me is the large amount of noise at my work bench, which was being picked up by the computer, or even just the signal generator connected to the scope. It was about 600 mV noise p-p. After some investigation, I figured out that a lot of it was coming from an old computer running at the work bench. I moved that computer to a new location about 12 feet away, and that reduced the noise down to about 100 mV p-p. After than, I tried inserting a simple RC filter after the signal generator, and that reduced noise further down to about 40 mV p-p.

I need at some point to build some kind of Faraday cage around the analog computer, but it is not a trivial matter as I would to find a metal box of the right size, remount the switches off the board, and figure out exactly how I would want to feed signals in/out of the box.

I got quite a lot of advice — some of it even useful — from the folks on the sci.electronics.design News group. Looks like Usenet really isn't dead. I didn't ask for the median age of the participants, however, which might be interesting to know. 😁

Folks kept telling me I need to move away from the white push-down breadboards and use this, that, or the other prototyping solution, usually involving some form of soldering. But I find the push-down breadboards so convenient, in so many ways. In particular, I mean the ease with which I can modify the circuit, if necessary (i.e., when I mess up a connection or layout) and also I like how they lock together easily, i.e., so long as your boards all have the same number of notches on the sides.

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