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6870

High-slope pentode for RF, video, wideband amplification, and small-transmitter service, bridging broadband voltage gain with modest RF power capability.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 600 mA

Description

High-slope Trustworthy RF and video pentode for small transmitting, video, and wide-band amplifier service, with 6.3/12.6 V heater operation.

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: 6.3 V
Nominal heater current: 600 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: Yes

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: 230000 Ω
Transconductance: 0.0085 S
Max plate voltage: 300 V
Max screen voltage: 250 V
Max plate dissipation: 6.3 W
Max screen dissipation: 2 W
Max cathode current: 50 mA

STC/Brimar 6870 indirectly heated fully screened VHF power pentode for Class C RF power amplification, frequency multiplication up to 150 MHz and high-level video service, also rugged mobile/aircraft applications. Center-tapped heater supports 6.3 V 0.6 A parallel or 12.6 V 0.3 A series wiring; parent HasSeries true and existing alternate heater parameters retained. Manufacturer normal maximum plate 300 V, grid-2 screen 250 V, plate dissipation 6.3 W, screen dissipation 2 W, cathode current 50 mA. Higher 500 V no-current plate/screen supply allowances are distinct from normal operating electrode maxima. Typical Class A at Va=Vg2=250 V, cathode resistor 120 Ω: Ia 25 mA, screen 3.5 mA, gm 8500 µmhos (0.0085 S), approximate rp 230 kΩ. Alternate at Va=Vg2=180 V, cathode resistor 56 Ω: Ia 25 mA, screen 3.5 mA, gm ~9000 µmhos, rp ~170 kΩ. Unshielded capacitances input 8.5 pF, output 7 pF, grid-to-plate 0.025 pF max. Basing JETEC 9BF.

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

1954 STC Brimar

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

Heater voltage (A-C. or DOCO).ll.tooooo.-n-.oo.o.-ooc.o-....o.t 1 2.6/§.3volts
3 V
Heater voltage (A-C. or DOCO).ll.tooooo.-n-.oo.o.-ooc.o-....o.t 1 2.6/§.3volts
Grid Noe.2 voltagCeesesesssesosesnase 250 180 DCvolts
2 V
Grid Noe.2 voltagCeesesesssesosesnase 250 180 DCvolts
Cathode bias resistOresesssessssssns 120 56 ohms
56 ohms
Cathode bias resistOresesssessssssns 120 56 ohms
Grid No.1 voltage (approximately)
1 V
Grid No.1 voltage (approximately)

Other

Maximum heater—cathode VOLltaZCeseesnsnsossscesssssssesssassnesnse ~90volts
90 V
Maximum heater—cathode VOLltaZCeseesnsnsossscesssssssesssassnesnse ~90volts
Maxcimum grid No.2 VOlta-geot-uooooooaoooooouoo-n-u'c-o.oto.oo..o 250DCvolts
2 V
Maxcimum grid No.2 VOlta-geot-uooooooaoooooouoo-n-u'c-o.oto.oo..o 250DCvolts
Maximum plate supply voltage (Ib =0 mA)oo-u-ooo~.ocooo.o-¢oono 500ICvolts
0 mA
Maximum plate supply voltage (Ib =0 mA)oo-u-ooo~.ocooo.o-¢oono 500ICvolts
Maxcinmm grid No.2 diSSip&tiOn..u...o...u.u...u.......n...o 20watts
20 W
Maxcinmm grid No.2 diSSip&tiOn..u...o...u.u...u.......n...o 20watts
Maximum grid Noe! currentescsescscsccssscssscsesssscoscsscssass 3.0mA
3 mA
Maximum grid Noe! currentescsescscsccssscssscsesssscoscsscssass 3.0mA
Maximum cathode ourreNtesccssssssoccrssscssssnsnsssncssssessnns 50 mA
50 mA
Maximum cathode ourreNtesccssssssoccrssscssssnsnsssncssssessnns 50 mA

Data set 02

1958 Brimar Radio Valve No 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Heater Voltage Alternate
12.6 V
Series
Heater Current Alternate
300 mA
Series

Characteristic

Application
RF and video amplifier / small transmitting valve