This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time. The circuit is from the 90's, not being given the power supply.
This 6-transistor receiver was manufactured in Japan in the 60s. The circuit is superheterodyne and has a 6V...
This circuit was found in a 1986 documentation and it may be difficult to obtain some of its...
This circuit was found in a 1980s documentation. The low voltage circuit uses a PUT. Transistors can...