The circuit shown uses an unusual regulator currently, which is the LM2935, which must be mounted on a heat radiator. The circuit is from Motorola's Linear Interface ICs.
This small transmitter with 2 transistors can reach several hundred meters using a 30 to 70 cm...
Although modern integrated versions exist, this 1995 circuit shows a discreet solution with common...
This circuit from Ferranti was released in 1969. It makes use of the company's transistors that admit...