We found this balanced modulator circuit for DSB and possibly SSB transmissions in US 1980s telecommunications documentation. The diodes can be replaced with equivalents.
In this circuit, the relay remains closed by activating a lamp, for a time that depends on the...
The figure shows how to connect a 7400 to obtain a bistable configuration. The circuit must be...
The circuit is from an old documentation making use of an operational amplifier of the time. The...