This transistorized stage has a high gain, being adjusted by VR1. The circuit can be used as an excellent audio preamp. We found this circuit in a 1996 English publication.
Found in older documentation this setting applies to modern components, noting that the power...
This circuit can send signals in both the VHF and FMN bands with a range of a few tens of meters. The...
This circuit indicates when the voltage of a 12 V battery is low. With changes, for example, the...