Voltage - Triode (single) ·Triode
OSRAM triode valve for general electronic service. Available source material does not establish a narrower functional application confidently.
A537: OSRAM triode valve. The complete approved OSRAM sheet was read for construction, characteristics, operating data, and application guidance.
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 promoted where reliably identified; additional source values retained below.
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.
Heater/filament voltage
4 V
Heater/filament current
400 mA
Plate impedance
10000 ohm
Mutual conductance
1550.0000000000002 uS
Amplification factor
15.5
Application
Initial stages of microphone amplifiers
Design feature
Very low microphony and background noise
Maximum anode voltage
150 V
Data set 02
Published operating points and test conditions from this source.
Amplification factor
15.5
Plate impedance
10000 ohm
Mutual conductance
1550 uS