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Power - Beam (NOT sweep) ·BeamPower

TT21

High-current Marconi beam tetrode for RF amplification, audio output, and pulse modulation, with 45 W plate dissipation and substantial peak-current capability.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
IO
Base pins
-
Nominal heater
6.3 V / 1.6 A

Description

The TT21 is a beam tetrode for RF power amplification up to about 30 MHz, also useful as an audio-output valve and pulse modulator.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
IO
Base pins
-
Nominal heater voltage
6.3 V
Nominal heater current
1.6 A
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

Beam Power

X-ray radiationInterelectrode capacitances
Plate resistance
12000 Ω
Transconductance
0.011 S
Max plate voltage
1250 V
Max screen voltage
600 V
Max plate dissipation
45 W
Max screen dissipation
6 W
Max grid dissipation
2 W
Max cathode current
230 mA

Published maximum ratings and characteristics audited; remaining useful numerical data retained in parameter table.

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

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

  • Beam tetrodes with oxide coated cathodes, the TT2 [1]

    1

    Beam tetrodes with oxide coated cathodes, the TT21 and TT22 are identical except

  • Beam tetrodes with oxide coated cathodes, the TT2 [2]

    2

    Beam tetrodes with oxide coated cathodes, the TT21 and TT22 are identical except

  • at frequencies up to

    30 MHz

    at frequencies up to 30Mc/s and are also useful as audio output valves and pulse modulators.

  • HEATER TT2 [1]

    1

    HEATER TT21 TT22

  • HEATER TT2 [2]

    2

    HEATER TT21 TT22

  • iarpk) (pulse) [1]

    75

    iarpk) (pulse) 75 7-5 A

  • iarpk) (pulse) [2]

    7

    iarpk) (pulse) 75 7-5 A

  • iarpk) (pulse) [3]

    -5

    iarpk) (pulse) 75 7-5 A

  • Rg1 -k (cathode bias) [1]

    220

    Rg1 -k (cathode bias) 220 220 kQ

  • Rg1 -k (cathode bias) [2]

    220

    Rg1 -k (cathode bias) 220 220 kQ

  • Efficiency [1]

    61

    Efficiency 61 75 78 81 %

  • Efficiency [2]

    75

    Efficiency 61 75 78 81 %

  • Efficiency [3]

    78

    Efficiency 61 75 78 81 %

  • Efficiency [4]

    81

    Efficiency 61 75 78 81 %

  • Efficiency [1]

    59

    Efficiency 59 74 765 74-5 795 %

  • Efficiency [2]

    74

    Efficiency 59 74 765 74-5 795 %

  • Efficiency [3]

    765

    Efficiency 59 74 765 74-5 795 %

  • Efficiency [4]

    74

    Efficiency 59 74 765 74-5 795 %

  • Efficiency [5]

    -5

    Efficiency 59 74 765 74-5 795 %

  • Efficiency [6]

    795

    Efficiency 59 74 765 74-5 795 %

  • Efficiency [1]

    72

    Efficiency 72 76 80 81 %

  • Efficiency [2]

    76

    Efficiency 72 76 80 81 %

  • Efficiency [3]

    80

    Efficiency 72 76 80 81 %

  • Efficiency [4]

    81

    Efficiency 72 76 80 81 %

  • Efficiency [1]

    70

    Efficiency 70 755 785 82

  • Efficiency [2]

    755

    Efficiency 70 755 785 82

  • Efficiency [3]

    785

    Efficiency 70 755 785 82

  • Efficiency [4]

    82

    Efficiency 70 755 785 82

  • Efficiency [1]

    63

    Efficiency 63 69

  • Efficiency [2]

    69

    Efficiency 63 69

  • Fig [1]

    1 A

    Fig. 1. Constant anode current curves at Vg2==300V.

  • Fig [2]

    300 A

    Fig. 1. Constant anode current curves at Vg2==300V.

  • Fig [1]

    2 A

    Fig. 2. Constant screen current curves at Vg2=2300V.

  • Fig [2]

    2300 A

    Fig. 2. Constant screen current curves at Vg2=2300V.

  • Fig [1]

    3 A

    Fig. 3. Constant grid current curves at Vg2=300V.

  • Fig [2]

    300 A

    Fig. 3. Constant grid current curves at Vg2=300V.

  • Fig [1]

    4 A

    Fig. 4. Anode current curves at Vg2=300V and Vg negative.

  • Fig [2]

    300 A

    Fig. 4. Anode current curves at Vg2=300V and Vg negative.

  • Fig [1]

    5 A

    Fig. 5. Constant anode current curves at Vg2=600V.

  • Fig [2]

    600 A

    Fig. 5. Constant anode current curves at Vg2=600V.

  • Fig [1]

    6 A

    Fig. 6. Constant screen current curves at Vg2=600V.

  • Fig [2]

    600 A

    Fig. 6. Constant screen current curves at Vg2=600V.

  • Fig [1]

    7 A

    Fig. 7. Constant grid current curves at Vg2=600V.

  • Fig [2]

    600 A

    Fig. 7. Constant grid current curves at Vg2=600V.

  • Fig

    8 A

    Fig. 8. Anode current curves for pulse modulator applications.

  • Fig

    9 A

    Fig. 9. Screen current curves for pulse modulator applications.

  • Fig

    10 A

    Fig. 10. Grid current curves for pulse modulator applications.

  • Fig

    12 V

    Fig. 12. Class C telegraphy. Power output/anode voltage curves.

  • Fig

    13

    Fig. 13. Anode modulated class C telephony.

  • Heater voltage

    6.3 V

    Published heater rating.

  • Heater current

    1.6 A

    Approximate published heater current.