We found this balanced modulator circuit for DSB and possibly SSB transmissions in US 1980s telecommunications documentation. The diodes can be replaced with equivalents.
This circuit activates a relay when raindrops fall on the sensor. The circuit is from 1960...
Instead of the lamps, LEDs can be used in series with 470 ohm resistors. The circuit is from an...
This circuit is quite simple to assemble, having been found in a traditional American publication. The...