Voltage - Triode (single) ·Triode
Low-frequency amplifying triode with comparatively low impedance, also suitable as an anode-bend or power-grid detector in early receivers.
Low-frequency amplifying valve combining useful amplification with comparatively low impedance; also suitable as anode-bend or power-grid detector.
European 4-pin base
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
Published characteristics/ratings were promoted when unambiguous; remaining operating values are preserved in TUBE_SECTION_PARAMETER. Marconi L2B directly heated 2 V low-frequency amplification triode with comparatively low impedance, also applicable to anode-bend and power-grid detectors. Approximate plate operating ranges: power-grid detector 80–150 V; anode-bend detector 50–150 V with grid bias approximately -1 to -2 V; LF amplifier 75–150 V with appropriate negative bias. Transformer coupling supports substantial signal handling; these are typical service ranges, not new absolute maxima.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Anode voltage
80 to 150 V
Power-grid detector
Anode voltage
50 to 150 V
Anode-bend detector
Anode voltage
75 to 150 V
Low-frequency amplifier
Data set 02
Published operating points and test conditions from this source.
Filament Voltage
2 V
Amplification Factor
15.5
Maximum/Published Anode Voltage
150 V
Typical Detector Anode Voltage
80-150 V
Typical LF Amplifier Anode Voltage
75-150 V