6AM6

High-slope miniature pentode for wideband RF, IF, and video-frequency amplification in communications and television equipment.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 7DB
Socket code: B7G
Base pins: 7
Nominal heater: 6.3 V / 300 mA

Description

High-slope miniature RF pentode for wide-band RF, IF, and video-frequency service; formerly coded 8D3 and equivalent to CV138.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 7DB
Socket code: B7G
Base pins: 7
Nominal heater voltage: 6.3 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7DB - 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

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 1000000 Ω
Transconductance: 0.0075 S
Amplification factor: 70
Max plate voltage: 300 V
Max screen voltage: 250 V
Max plate dissipation: 2.5 W
Max screen dissipation: 0.8 W

Brimar 6AM6 (previously coded 8D3) indirectly heated high-slope sharp-cutoff B7G miniature RF pentode for RF/IF/video wideband amplification and television; usable as a frequency changer to about 100 MHz with external oscillator. Heater 6.3 V 0.3 A. Manufacturer rating differences: GE handbook gives max plate 300 V and max screen 250 V (existing promoted limits retained), while Brimar specifies max plate 275 V and max screen 275 V; do not silently merge competing manufacturer's rating systems. Max plate dissipation 2.5 W, screen dissipation 0.8 W. Typical at plate/screen 200 V, control grid -1.5 V, cathode resistor 135 Ω: plate 9 mA, screen 2.25 mA, gm 7.5 mA/V (0.0075 S), approximate rp 0.8 MΩ. Alternate at plate/screen 250 V, grid -2 V, cathode resistor 160 Ω: plate 10 mA, screen 2.6 mA, gm 7.3 mA/V, rp 1 MΩ. Inner amplification factor g1-to-g2 ~70; existing gm 0.0075 S, plate resistance 1 MΩ and mu 70 retained. Suppressor grid to cathode. Approximate cutoff control-grid -4.5 V at 200 V or -5.5 V at 250 V. Shielded capacitances input ~7.5 pF, output ~3.2 pF and grid-to-plate ~0.01 pF.

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.

Data set 01

1958 Brimar Radio Valve No 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate Voltage
250 V
Plate Current
10 mA
Screen Voltage
250 V
Screen Current
2.6 mA

Characteristic

Plate Resistance
1 Mohm
Transconductance
7300 µS
Amplification Factor
70
Frequency Changer Maximum
100 MHz

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Maximum plate voltage
300 V
Published handbook rating
Maximum screen voltage
250 V
Published handbook rating
Plate voltage
250 V
ClassA
Screen voltage
250 V
ClassA
Control-grid bias
2 V
ClassA
Plate current
10 mA
ClassA
Screen current
2.5 mA
ClassA

Characteristic

Plate resistance
1000000 ohm
Published handbook characteristic
Transconductance
7500 µS
Published handbook characteristic
Heater voltage
6.3 V
Published heater rating
Heater current
300 mA
Published heater rating