3-tube receiver 2 (T1603E)

Using known tubes, this receiver was found in a Radio Electronics from 1949. The circuit does not include the power supply.

Password Lock (CB21545E)
We found this circuit in a 1998 documentation. The circuit makes use of CMOS logic and must be...
Programmed gain amplifier (CB7266E)
Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally...
Video amplifier 2 (CB9418E)
Found in an old American publication, this is one of many possible configurations for an analog...