This circuit for medium and short wave range was found in an American documentation from 1992. The circuit can use general purpose transistors and the antenna can be external or telescopic.
This simple experimental circuit using only transistor produces a tone given by C1 and C2. Tone is...
This power supply may have 5, 6, 9 or 12 V outputs depending on the 78XX and 79XX series...
This circuit is from Philips' 60s documentation. The circuit can be applied to modern operational...