11-12-2015, 06:32 PM
(11-12-2015, 04:51 PM)Nowhere-Man Wrote: As to the book. I did come across a way to measure the inductance of a coil using an electric buzzer and a calibrated crystal radio. I wasn't sure where the book was going with the maths calculation, though. I know how to calculate a resonant frequency using Pi and division by 1000000, plus using square roots but, unfortunately, the book was vague and it helps if they give an illustrated example. Anyway, you use headphones to tune into the buzzing and that should give a calibration mark on the dial you can use perhaps with the fixed capacitor to work out the inductance. Sadly it gives too little detail.
Gosh - that sounds like a complicated way to do it!
Mind you, I can't think of an obvious way to do it with minimal test gear. A signal generator and a volt meter are a sensible minimum, but back then these would have been expensive tools. We're lucky that today, £10 or thereabouts gets one of those magic "test everything" component testers from China.
