This circuit was found in a documentation of the 80s, having didactic purpose. For R1 values between 10k to 1M can be used. Transistors are general purpose types.
This circuit was obtained in a magazine for radio amateurs 73 of the 90s. The circuit is based on...
This input stage has unit gain but a high input impedance and low output impedance. The circuit is...
May 2016 - It can be obtained from Mouser Electronics new display 1092 from VDC. The new LED...