Only for reference this is a circuito f a commercial receiver of the year 1958. The circuit uses coils and transformers hadr to find in our days. The circuit is destinated to receive MW stations.
Other operational amplifiers of the same series can be used on this circuit found in Motorola's Linear...
Found in 1980s documentation, this circuit produces 1 Hz flashes. The op amp supports equivalent. R5...
In the figure we have the way to use a single control voltage to act on two varicaps...