Most hobbyists use crystals as an external clock signal for a microcontroller. A less common use would be to make a bandpass filter (BPF) for an RF signal. [Dan Watson] explains his crystal ladder … ...

This article is part of the Ideas for Design Series: Vol. 3, No. 9. Many communications and sensor applications require a bandpass filter with wide bandwidth. This filter typically requires ...

A new instrument has been developed to implement highpass, lowpass and bandpass filters. The Model 601 tunable highpass/lowpass filter contains a tunable 8-pole Butterworth highpass ...