Push pull amplifier (CB21941E)

Using a pair of CK722s, this booster step of a few milliwatts of power was obtained in a 1960 Gernsback publication.

Telephone Line Tester (CB21266E)
We found this circuit in a Radio Electronics from the 90s. The circuit is for conventional analog...
Microphone Micro Amplifier (CB19624E)
The operational of this amplifier can be the 741 and the resistors R1 and R3 are of 10 k. R2B is...
Sequential 4017 and Neon Lamp (CB10508E)
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...