5-tube commercial radio (T1619E)

This commercial superheterodyne receiver was found in a 1949 Radio Electronics. The circuit uses battery.

Motion Sound Control (CB6312E)
With this circuit you can produce the sound effect passing from one channel to another. The...
Temperature indicator (CB9308E)
The sensors in this circuit are NTCs and PTCs that work in a differential way by directly...
Basic Monostable with the 555 I (CB1295E)
This basic configuration can be found in a lot of articles on this site. In this case, the relay...