We found this small FM transmitter in an Australian publication from 1991. The 3-transistor circuit has a range on the order of 400 meters.
This circuit, obtained from a 1965 magazine, can still be assembled using some modern equivalent...
This source was obtained from a book on transistors from the 60's. The circuit uses germanium...
This powerful inverter provides a high-quality sine wave signal. I found it in a Radio Electronics issue...