Tube-number record
12/04 HM / 12/04 JM
0 archive entries
BrandFERRANTI
ClassRadar Display Tube
BaseDuodecal
Filament6.3 V @ 300 mA
Construction
Primary TypeDisplay / CRT
EnvelopeGlass
Base MaterialPlastic/Bakelite
SectionsSingle
Filament / Heater
Heater NotesIndirectly heated
Absolute Maximum Ratings
Plate Voltage15000 V
Grid 2 Voltage600 V
Cathode Current0.5 mA
H-C Voltage200 V
Audio Performance
Key Features
- 12-inch diameter
- Flat faced
- Metal backed screen
- Long persistence phosphor
- Primarily for P.P.I. applications
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| PPI Display | 15000 V | — | — | — | 0.05 mA |
Application Notes
The HM variant uses Orange phosphor (Type H), while the JM variant uses Blue/Yellow phosphor (Type I). The HM tube has a magnesium fluoride screen liable to burn if the spot is stationary.
0 results