Broadband amplifier (CB9179E)

Found in an old Popular Electronics, this circuit has a gain of 20 dB. The integrated circuit is uncommon today.

Call indicator (CB7235E)
We found this circuit in an old neon lamp application manual. The circuit stores a call. The...
Audio Interface with Optocoupler (CB25495E)
This isolation circuit for audio signals was found in the August 1992 issue of Radio Electronics...
Fuzz 4 (CB4874E)
This fuzz uses only one transistor that can be the BC548. Signal input and output cables must be...