This receiver was found in an article in Electronics Now magazine in March 1994. The coils are critical, as shown in the figure. Listening is through headphones.
This circuit can measure frequencies up to just over 1 MHz and uses CMOS technology. The circuit is...
This variable oscillator was found in a Mullard transistors manual from 1960. The resistor R5 is...
This circuit, from a 1988 documentation, consists of an automatic temperature control using an NTC...