We found this circuit that can reach 50 MHz in the February 1997 Electronics Now magazine. The integrated circuits used are not very common today.
This low noise preamplifier has a gain of 19 dB in the 30 MHz band. The circuit is from the 80s....
Found in American documentation from the 90s, this configuration detects the direction of rotation...
This circuit generates a 5.3 kHz linear ramp with the indicated components. The 7555 is the CMOS...