This powerful transmitter for the 27 MHz band was found in a Japanese publication from 1961. The circuit is powered by battery and has the details of the coils given next to the diagram.
We found this circuit in an English magazine from 1976. The magazine no longer exists, but just...
The figure shows a simple way to have emergency power for a 9 V circuit powered by a source. If...
Found in an Electronic Design from the 90's, this circuit supplies voltages according to the...