6SN7 Preamplifier (T1105E)

This preamp circuit has a typical configuration as found in a 1946 publication. Supply voltages are indicated.

High Voltage Status Indicator 6N138 (CB1555E )
The circuit shown in the figure can be used as a high voltage indicator on a power supply line of...
555 Doorbell (CB25531E)
This simple circuit was found in the November 1992 issue of Radio Electronics magazine. It...
Ultrasound Emitter (MSB122E)
The circuit shown by the figure below can produce signals in the range between 20 kHz and 30 kHz....