This circuit was found in Radio Electronics magazine from June 1958. The maximum distance depends on cable losses. More stations can be added.
This source allows the supply of laser diodes with voltages above 11 V. The circuit is from French...
This circuit uses an 18 MHz crystal to generate 36 MHz signals. We found it in an 80's...
This circuit monitors the current in the negative line. The circuit is from a 2005 Linear...