(no subject)

I guess I have a question for an electronics forum. But just in case one of my readers has an answer, and for my own records about what I've been up to.

I built a little stroboscope from a Velleman kit I bought at Am-sci. It's a good, simple device and soldering it all together was straight-forward. I planned to use it, along with a printable timing disc, to time my turntables. It It has an adjustable blink rate, so I got the blink signal on my oscilloscope and adjusted it as close as I could to spot-on 60 hz. (60hz is the nominal mains line frequency [in the US] so it's a handy timing reference that everyone has available.) But when I used it to check the timing on my turntable with an integral mains-frequency stroboscopic timer, the two did not agree.

What do you do when different pieces of equipment do not all agree? What do you do if you need a really solid frequency standard to check your equipment against? How do I tell if my oscilloscope is out of calibration?

Thinking about it more, I may have gotten some math wrong when mixing base-ten with base-sixty units, so I'll play around with it again tonight and do math on paper instead of in my head. I'd still like to know about good options for a frequency standard.

My Bicycle, Longing

My bike, Longing, in bright light outside my condo building.

I was thinking about how much of Longing is original as I rode home a few days ago; it's not very much. The frame (including headset and front fork), the gear shifters, and the brake levers are original. I'm pretty sure everything else on him has been replaced, in some cases multiple times. He'll turn 21 in two years. I've ridden so many thousands of miles on him...