This circuit is from a Popular Electronics from the 90's. The circuit provides an output for a control stage.
With this circuit it is possible to tune the signals in the 50 MHz band in a common AM receiver around...
This circuit is from a 1980 publication. The circuit has high gain with weak signals and lower gain...
The original document is from Philiups, but now available from NXP (www.nxp.com), which is the...