Found in a 303 Circuits from the 90s, this circuit converts signals from the 10 kHz to 150 kHz band to the 4.01 to 4.15 MHz band.
We found this circuit in an old publication. The circuit can be implemented with modern equivalent...
Operational amplifiers used in this 80's circuit is not very common today, but the setting can be...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...