Data set 01
1961 Tung Sol
Published operating points and test conditions from this source.
SECTION 1
Tetrode
Other
Heater voltage
2.5 V
Nominal
Plate voltage
12 V
Typical operating conditions
Screen voltage
11 V
Typical operating conditions
Voltage Pentode or Tetrode (under 100V) ·Tetrode
7851
Screen-grid electrometer tetrode with extremely low grid current and very high effective gain, designed for precision instrumentation involving minute input currents.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- -
- Socket code
- B7G
- Base pins
- 7
- Nominal heater
- 2.5 V / 200 mA
Description
The 7851 is a screen-grid electrometer tetrode with very high effective gain and extremely low grid current, intended for instrumentation involving minute input currents.
Socket description
Miniature 7-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B7G
- Base pins
- 7
- Nominal heater voltage
- 2.5 V
- Nominal heater current
- 200 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
Tetrode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 1700000 Ω
- Transconductance
- 0.00004 S
- Amplification factor
- 5
- Max plate voltage
- 12 V
- Max screen voltage
- 12 V
Electrometer tetrode.
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 02
1966 Tung Sol Electronic Tubes 4 of 4
Published operating points and test conditions from this source.
SECTION 1
Tetrode
Characteristic
Grid-to-plate capacitance
0.19 pF
WholeTube
Input capacitance
2.6 pF
WholeTube
Output capacitance
1.8 pF
WholeTube
Grid To Plate: G1 To P
0.19 pf
PublishedTable
Heater
2.5 VOLTS
PublishedTable
Plate Supply Voltage
11 VOLTS
PublishedTable
Grid #2 Voltage
11 VOLTS
PublishedTable
Grid #1 Voltage Applied
2.2 VOLTS
PublishedTable
Transconductance
40 uMHOS
PublishedTable
Plate Resistance
1.7 MEGOHMS
PublishedTable
Other
Plate supply voltage
11 V
WholeTube
Grid 2 voltage
11 V
WholeTube
Grid 1 voltage
-2.2 V
WholeTube
Plate current
16 uA
WholeTube
Grid current maximum
0.000000001 mA
WholeTube
Maximum Plate Voltage
2 VOLTS
PublishedTable
Maximum Grid #2 Voltage
12 VOLTS
PublishedTable
Maximum
12 VOLTS
PublishedTable
Maximum
1 VOLTS
PublishedTable
Maximum
16 VOLTS
PublishedTable
Grid Current - Maximum
13 AMPS
PublishedTable