This circuit for the very low frequency range was found in the Radio Electronics magazine of February 1983. The components are according to the frequency range to be amplified.
The range for this transmitter is up to 100 m. The signal can be received by any circuit tuned for the...
We found this circuit in a Popular Electronics of the 80s. The circuit can be made with almost any...
Found in Popular Electronics from the 90s, this circuit serves to indicate the output level of a...