This circuit was found in Philips documentation from 1967. The components are of the time, being transistors like BCY38 for TR1, BC108 for TR3, and others depending on currents.
This circuit, obtained from the component manual used, has an ultra narrow 1 kHz range given by...
Utilizing the MAX4172 or MAX495 integrated circuit, this circuit increases the sensitivity of a...
This circuit uses an unusual component today which is the integrated circuit. We found this...