This 13 A V power supply with 2 A uses a transformer with 12 V of secondary and 2 A of current. The diodes can be 1N5404 or equivalent for 2 A or more.
This antenna for the frequencies 146 or 440 MHz was found in a magazine 73 for Amateur Radio of...
We found this circuit in an 80's EDN. The circuit makes use of a MAX680, being given a table with...
This circuit was found in a 1986 publication. However, it can still be easily assembled, as the...