The transistor used in this circuit is uncommon today. AC124 or equivalent such as AC188K and 2N2431 can be used. The circuit is from the 80's and makes use of transformers.
This simple low-power circuit uses, in the original version of 1965, germanium transistors. The...
With this configuration we have a voltage follower, amplifier with unit gain, in which the output...
With this passive circuit it is possible to modulated in amplitude a low intensity RF signal. The...