100 dB amplifier (T448E)

This circuit for VHF signals was found in an MIT documentation from the 1940s. The circuit operates with 4 tubes and has a gain of 100 dB.

FM Decoder (CB4601E)
Frequency modulated signals up to 500 kHz can be decoded with the PLL we show. The demodulated signal...
Integrated Digital Circuits Test (CB3895E)
We found this circuit in an American documentation of the 80's, being indicated for the test of...
AC134 or AC126 stage (CB4267E)
This step uses germanium transistors such as the AC151, GE2, and others having been found in a...