Good day all, I have a question: I built a passive high pass filter in an experiment using a hand wound inductor (toriod) and a resistor. The filter worked great as a high pass at frequencys ranging from 100 Hz - 1,000,000 Hz (rolling off around 10,000 Hz). After creating a bode plot, I noticed that at very high frequencies (relative) around 5-10 MHz, the filter began to roll off slightly. What causes this unwanted behavior? * feel free to be "mathy"