Data set 01
1959 Telefunken
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
Maximum frequency
800 MHz
Application
Application
Grounded-grid UHF amplifier
Voltage - Triode (single high frequency) ·Triode
4CM4
Telefunken 4CM4 indirectly heated miniature UHF grounded-grid amplifier triode for frequencies to 800 MHz, with 4 V 300 mA heater and 14 mA/V transconductance.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- -
- Socket code
- B9A
- Base pins
- 9
- Nominal heater
- 4 V / 300 mA
Description
UHF triode for grounded-grid amplifier service up to approximately 800 MHz.
Socket description
Small-button Noval 9-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B9A
- Base pins
- 9
- Nominal heater voltage
- 4 V
- Nominal heater current
- 300 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
1 physical section, each with unique specifications.
Section 1
Triode
X-ray radiationInterelectrode capacitances
- Transconductance
- 0.014 S
- Amplification factor
- 68
- Max plate voltage
- 220 V
- Max plate dissipation
- 2.2 W
- Max cathode current
- 20 mA
Telefunken 4CM4 1959 UHF grounded-grid triode. Heater 4 V 0.3 A, typical heater 3.8 V. Max plate 220 V, dissipation 2.2 W, cathode current 20 mA, negative grid voltage magnitude 50 V, heater-cathode ±100 V, grid resistor max 1 MΩ. Typical Va 175 V, Vg -1.5 V, Ia 12 mA, gm 0.014 A/V, mu 68. UHF amplification to 800 MHz, at 100 MHz gm phase -7°, additional noise conductance 0.5 mmhos. Capacitances shielded/unshielded: Cgp 3.1/2.0 pF, Cpk unshielded 0.2 pF, Cgk unshielded 3.6 pF, input g-(h+k) 4.2/3.9 pF, output p-(h+k) 0.25/0.3 pF. Plate pins1/9, grid2/6/8, cathode3/7, heater4/5. No plate resistance specified.
Source-dependent data
Operating conditions by source
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.