I finally put my frequency counter kit together yesterday. It's based on a circuit designed by a ham radio geek named Wolfgang Büscher ( DL4YHF ). He notes on his webpage that he doesn't mind folks monetizing the design, but it would be nice if they credited him. The seller I bought my kit from actually did via a link to his website for instructions, so that's nifty.
The frequency counter is the device in the lower right with the numerical display. I'm going to see if Mark can help me print a case for it. It runs on 7-9 volts with an onboard regulator. The regulator is a surface mount device; the first one I've ever soldered. I used advice from the Michael Geier book I own; a quick tack-solder on one connector, get the other pins connected nicely, then reflow the first pin. I guess it works! I'm still going to stick with through-hole if I possibly can for right now.
I made my own power cord for it too. I've been buying wall-warts just for their cords and plugs so I can get an array of different sizes. I found the right one, cut it off the power pack, and soldered spade connectors on to it to fit my desktop power supply (that I also made myself from a kit). I turned it up to 8 volts and powered on the counter. I had to bend a cap out of the way because it was shorting two of the 7-segment display pins, but after that it worked fine. I'm pleased with myself.
On the upper left is my B&K VOMatic made in Chicago in the early '60s. I actively use it for my putterings including, in this case, checking resistor values before soldering them into the counter. Using something older than me, that I *also* fixed and cleaned up myself, in daily work makes me really happy.
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All that said, I still don't feel like I really know very much at all about electronics. I think this is probably irrational, and I don't know if there is some threshold I'll pass at some point that changes my mind.