This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit equivalents although the indicated types can still be found with some ease.
We found this transistorized radio for the AM band in a Japanese publication from 1960. The...
This small source is suitable for low consumption equipment that uses batteries. The circuit is...
Found in a magazine 73 for radio amateurs, this circuit has two settings, one for the interval and the...