Current to voltage converter for grounded loads (CB9338E)

Found in an Electronic Design from the 90s, this circuit uses components from that time.

Recording tapes eraser oscillator (CB7303E)
This 70 kHz oscillator is used to erase tapes in pre-recording. The circuit is from 1968 General...
Automatic Frequency Control (CB4101E)
We found this circuit in an old documentation for hams. In it we have the way to use a varicap to...
Touch or Proximity Alarm (CB17329E)
This sensitive touch circuit that triggers an oscillator uses only transistors. The circuit is...