1N3129
The 1N3129 is a 20 mA Germanium tunnel diode. 1N3129 Specifications (from http://www.americanmicrosemi.com/catalog/1N3129.html):
- Peak current: 20 ± 1 mA
- Total capacitance: 20 pF
- Peak to valley current ratio: min. 8.0
- Peak voltage: 100 mV
- Valley voltage: 300 mV
- Forward voltage at peak current: 575 mV
- Series inductance: 0.6 nH
- Series resistance: 2.5 Ω
- Semiconductor material: Germanium
- Maximum operating temperature: 100 °C
- Package style: DO-25var
- Mounting style: T