See manual here:
https://www.radioelec.com/images/Image/ERSATZ%20TRIODE_english.pdf
Characteristics :
- Old triode ersatz module
- Small dimensions allow it to be easily inserted into the circuit or into the tube base.
- The connections are simple:
1 wire to connect to the grid pin
1 wire to connect to the pin Plate
1 wire to be connected to ground or to a filament terminal
- A small potentiometer allows to adjust the gain
- Module dimensions: Diameter 20 mm, max thickness 10 mm
- Compatibility:
Plate voltage 30 to 150 V
Amplification: 1 to 20 (adjustable)
"Plate" current: 1 to 6.5 mA
Composition:
- Comes with instructions and connection details
Use :
- Circuit for electrically replacing triodes type A405 - A409 - A410 - B410, probably also triodes TM, ...