Hearing aid amplifier (CB22355E)

We found this circuit in an English documentation from 1995. The components used are common nowadays. The phone is low impedance.

Beat frequency generator (CB20378E)
This circuit can be used to listen for SSB signals on receivers that do not have the built-in...
Low Impedance Preamp 2 (CB21895E)
This configuration was found in Raytheon's circuit manual from the 1960s. The circuit has an...
perature Controlled Oscillator (CB13025E)
Tem The CMOS oscillator illustrated in the figure has a frequency that depends on the temperature sensor, a...