This mixer with 20 dB gain per channel uses RCA's CA3048 integrated circuits. We found it in the July 1971 Radio Electronics magazine. The power supply does not need to be symmetrical.
This shield circuit allows recording of the signal from a serial output on a cassette recorder, with...
This Japanese radio receiver is from the 60s. It has 6 transistors and is powered by 4 batteries with...
The integrated circuit used is a voltage reference from Motorola. This configuration was obtained in...