Tuning Indicator ·Triode-TuningIndicator
Electron-ray tuning indicator combining a control triode with fluorescent display for visual tuning indication in AC-mains receivers.
4 V electron-ray tuning indicator. Electrical ratings and operating characteristics were extracted from the supplied 4-volt valve data table, including the published heater data and available section-level values.
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.
2 physical sections, each with unique specifications.
Section 1
Electron-ray tuning indicator.
Section 2
No fixed ratings are recorded for this section.
Fluorescent tuning-indicator section.
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
250 V
Triode current
3 mA
Control-grid voltage
-3 V
Screen voltage
250 V
Transconductance
2000 µS
Amplification factor
50
Plate resistance
25000 ohm
Data set 02
Published operating points and test conditions from this source.
Heater voltage
4 V
Heater current
320 mA
Plate voltage
250 V
Grid voltage
-3.5 V
Plate current
3 mA
Transconductance
2000 uS
Plate resistance
25000 ohm
Amplification factor
50
Indicator supply voltage
250 V
Indicator grid voltage range
-6 to +3 V
Maximum indicator current
1 mA