Telephone line monitor (CB10149E)

We found this circuit in a 1980s publication on telephony. The circuit uses an integrated amplifier from that time, which is uncommon today.

| Clique na imagem para ampliar |

Receiver for echo sounder (CB22357E)
Found in old documentation, this circuit is the receiver for the previous circuit. Components are...
XTAL Low Frequency Stable Oscillator (CB14152E)
We found this circuit in the 1994 Linear Applications Handbook by National Semiconductor. The...
8-Channel Switch (CB24698E)
This circuit switches the capacitors of a digital filter with the 4046 IC (PLL). The circuit was...