Found in Philips' 90s documentation, this small source can use modern transistors like the BD135 for TR4 and the BC series for the rest.
This circuit is one of many that we have in our section. It was taken from the Electronics...
This is a bridge for the measurement of low value resistances and high values too. The circuit...
This circuit for the two-meter band of radio amateurs was found in 1980s documentation....