This converter for the 150 MHz band was found in an American documentation. Transistors are uncommon today and equivalents can be used.
This amplifier for recording heads was found in a Radio Electronics from September 1963. The...
This circuit is from a 1970 publication, having been implemented with germanium PNP transistors. We can...
This circuit is from the Linear Applications Handbook of the National Semiconductor of 1994. The...