Broadband Balanced Mixer MC1556G (CB14563E)

We found this circuit in Motorola's Linear Databook in 1990. The integrated circuit used is no longer common today.

Audio Frequency Meter (CB20477E)
Found in a Popular Electronics from 1992, this circuit uses a PLL567 in an audio meter bridge that...
Sound switch or Vox (CB9215E)
Found in an EDN from the 90s, this circuit uses an electret microphone. The output can be used to...
Semiconductor Tester (CB18739E)
We found this circuit in an old documentation, but the circuit is current due to the components it uses and...