This passive tuned circuit was found in a 90s Popular Electronics. The coils must be according to the monitored waveband.
This circuit was found in an Electronics World of 1968. It can be applied to any modern triac and...
This frequency modulated light transmitter is from a 1990s documentation. The circuit may use...
This Radio Electronics circuit, in an 80's edition, decodes the 67 kHz signal used at the time to...