IFR 1200 SS|
Bryan's Old Computers
Yet Another Hobby...
I like test equipment (shiny objects and flashing lights). It's
another geek thing--but with a whole different set of geeks. :)
Back in the seventies, when I was a poor teenager and had to find my
test equipment without the help of ebay, I often had to resort to building
it myself. Money was tight, and good test equipment was very expensive. I
ended up making much of my own for fun and actual use. I built a lot of
simple things, logic probes, power supplies, semiconductor testers and
curve tracers, & etc.
One time I made a frequency counter in a probe--about the size of a
logic probe. To get it that small, all the chips were stacked like bricks,
with the pins bent outward, cut short and soldered point-to-point with
wire wrap wire. What a pain! It worked for a long time, but somehow I blew
a chip in the front end and the pain of replacing it was just too much. It
was cannibalized somewhat, and then discarded. I had big plans of starting
a business to sell them, but it was just too much trouble for a dumb high
My 'Frequency Probe' case design, 1978
My most ambitious project at the time was a 41/2-digit digital voltmeter of my own
design. It used a dual slope analog to digital converter that I had to learn about in
order to build. It took months to complete, but worked fantastically! I even added a
capacitance, current, and ohms function. I used it for years, and then
like most of my projects, cannibalized it for parts to build something
else. Today, nothing remains but a few of the precision resistors I used
in the voltage divider. -- My interest in preserving history is a recent one.
Check the above links to see my test equipment related projects.