This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an auxiliary relay with the call signal for a possible louder bell.
Found in American documentation from the 90s, this circuit uses TTL technology and is therefore...
Found in a 1968 Electronic Design, this circuit is intended for suppression of trigger noise in...
This amplifier for audio transmission lines was found in a 1961 American publication. The critical...