This circuit is from old American documentation, using a regulator integrated circuit that is uncommon today. The diodes can be 1N4002 and the transformer has a 500mA secondary.
We found this circuit in a Radio Electronics from October 1976. The components are still common, but...
Found in old documentation, this circuit is intended for low level amplitude modulation with low...
The integrated circuit used consists of an array of Darlington transistors for currents up to 3 A....