We found this balanced modulator circuit for DSB and possibly SSB transmissions in US 1980s telecommunications documentation. The diodes can be replaced with equivalents.
Despite being from a 1970 General Electric documentation this circuit can be used as a shield if...
This is another quick adder that we found in an Electronic Design from the 80s. It also applies to...
This circuit was found in a 1969 Mullard documentation. Used transistors can be replaced with...