This circuit was obtained from American documentation from the 1990s. The transformer can be a car ignition coil that works like an autotransformer. Q2 must be equipped with a heat sink.
This circuit is from a 1997 publication, but it can be assembled with a BD136 for TR1. The...
This long-time circuit uses a field effect transistor, which may be the BF245, and depends on a...
We found this transmitter in a Popular Electronics from 1992. The circuit transmits in the range of...