This step of two transistors has a high input impedance due to the use of FET. We can use BF245 for this function and the bipolar can be BC548. The circuit is from an 1975 American documentation.
This powerful amplifier with 2N3055 transistors at the output provides a few tens of watts rms on a...
With this circuit it is possible to receive and send audio signals simultaneously over the same...
This circuit generates 100 MHz signals from a 20 kHz crystal. The circuit is from an 80's...