The signal from this transmitter is injected into a cable that you want to follow along a pipeline. Monitoring is done using an ordinary AM receiver out of season.
Based on common components, this circuit was found in an English publication. The circuit is...
This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply...
In relation to the previous circuit (CB18493E) this spy has an extra transistor, which can be a...