I don't use the AADE meter (my inductance meter was scratch-built from the ARRL handbook) but the fundamental frequency of the signal is not what the inductor is reacting to in most modern designs
The one I use, which I believe is similar to the AADE in measurement methodology, applies a square wave to the inductance and measures the effect of the inductance on the waveform. What is of importance is the frequency of the leading and trailing edges of that square wave, which is many many times the fundamental frequency of the waveform. The steeper the edges, the higher their frequency. Graphically, consider the leading (or trailing) edge of the square wave a part of a sine wave of some frequency. Following the steep slope of the edge waveform, continue with it to draw a perfect sine wave. You will see that the actual frequency of that sine wave may be somewhere between 10 and 100 times the fundamental frequency of the square wave if it's a decent square waveform. That's the test frequency that the inductor is reacting to: the frequency of the leading or trailing edge. Now, the fundamental frequency of the square wave can be of importance because the measurement circuit often uses what happens to the waveform during the time when the square wave is at peak or zero voltage to calculate the inductance. The length of that time can affect the inductance value reported, depending upon the design of the circuit, but that frequency is NOT the "test frequency" the inductor is subjected to in the circuits that I've worked with. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
