This two-tube circuit, one being a double, was found in Radio Electronics magazine from July 1958. The distance to the microphone depends on noise and losses. The cable must be shielded.
Other amplifiers of the series like the MC3301, MC3401 and LM2900 can be used in this circuit. We found...
We found this balanced modulator circuit for DSB and possibly SSB transmissions in US 1980s...
Found in documentation from the 1980s, this converter or inverter circuit uses components from...