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25T

Eimac medium-mu transmitting power triode for audio-frequency amplifier or modulator duty and RF power-amplifier or oscillator service. Its 25 W plate dissipation and kilovolt-class plate ratings support compact transmitting applications.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: 4
Nominal heater: 6.3 V / 3 A

Description

The Eimac 25T is a power triode for audio-frequency amplifier or modulator and radio-frequency power-amplifier or oscillator service, usable at VHF frequencies.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: 4
Nominal heater voltage: 6.3 V
Nominal heater current: 3 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

Triode

X-ray radiationInterelectrode capacitances

Transconductance: 0.0025 S
Amplification factor: 24
Max plate voltage: 2000 V
Max plate dissipation: 25 W

Published maximum ratings and characteristics audited; additional applicable 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

1950 Eimac Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Grid - Plate
1.5
Grid - Plate 1.5 fLfLf
Grid-F ilame n t [1]
2
Grid-F ilame n t 2 .7 fLfLf
Grid-F ilame n t [2]
7
Grid-F ilame n t 2 .7 fLfLf
Plate -F ilament [1]
0
Plate -F ilament - 0 .3 fLfLf
Plate -F ilament [2]
3
Plate -F ilament - 0 .3 fLfLf
T ransconductance (I b= [1]
25
T ransconductance (I b= 25 rna., Eb= 100 0, e c =-1 5) 2 500 fLmhos
T ransconductance (I b= [2]
100
T ransconductance (I b= 25 rna., Eb= 100 0, e c =-1 5) 2 500 fLmhos
T ransconductance (I b= [3]
0
T ransconductance (I b= 25 rna., Eb= 100 0, e c =-1 5) 2 500 fLmhos
T ransconductance (I b= [4]
-1
T ransconductance (I b= 25 rna., Eb= 100 0, e c =-1 5) 2 500 fLmhos
T ransconductance (I b= [5]
5
T ransconductance (I b= 25 rna., Eb= 100 0, e c =-1 5) 2 500 fLmhos
T ransconductance (I b= [6]
2
T ransconductance (I b= 25 rna., Eb= 100 0, e c =-1 5) 2 500 fLmhos
T ransconductance (I b= [7]
500
T ransconductance (I b= 25 rna., Eb= 100 0, e c =-1 5) 2 500 fLmhos
D-C Plate Vo ltage [1]
7
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
D-C Plate Vo ltage [2]
50
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
D-C Plate Vo ltage [3]
1000
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
D-C Plate Vo ltage [4]
1500
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
D-C Plate Vo ltage [5]
2
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
D-C Plate Vo ltage [6]
0
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
D-C Plate Vo ltage [7]
200
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
D-C Plate Vo ltage [8]
0
D-C Plate Vo ltage 7 50 1000 1500 2 000 200 0 vo lts
Plate Dissipation, pe r t ube':' • • • • [1]
2 W
Plate Dissipation, pe r t ube':' • • • • 2 5 watts
Plate Dissipation, pe r t ube':' • • • • [2]
5 W
Plate Dissipation, pe r t ube':' • • • • 2 5 watts
D-C Grid Vol tage (app ro x . ) [1]
-20
D-C Grid Vol tage (app ro x . ) -20 - 30 -55 -80 vo lts
D-C Grid Vol tage (app ro x . ) [2]
30
D-C Grid Vol tage (app ro x . ) -20 - 30 -55 -80 vo lts
D-C Grid Vol tage (app ro x . ) [3]
-55
D-C Grid Vol tage (app ro x . ) -20 - 30 -55 -80 vo lts
D-C Grid Vol tage (app ro x . ) [4]
-80
D-C Grid Vol tage (app ro x . ) -20 - 30 -55 -80 vo lts
Peak A -F Grid Input Volt ag e [1]
205
Peak A -F Grid Input Volt ag e 205 2 10 2 30 27 0 vo lts
Peak A -F Grid Input Volt ag e [2]
2
Peak A -F Grid Input Volt ag e 205 2 10 2 30 27 0 vo lts
Peak A -F Grid Input Volt ag e [3]
10
Peak A -F Grid Input Volt ag e 205 2 10 2 30 27 0 vo lts
Peak A -F Grid Input Volt ag e [4]
2
Peak A -F Grid Input Volt ag e 205 2 10 2 30 27 0 vo lts
Peak A -F Grid Input Volt ag e [5]
30
Peak A -F Grid Input Volt ag e 205 2 10 2 30 27 0 vo lts
Peak A -F Grid Input Volt ag e [6]
27
Peak A -F Grid Input Volt ag e 205 2 10 2 30 27 0 vo lts
Peak A -F Grid Input Volt ag e [7]
0
Peak A -F Grid Input Volt ag e 205 2 10 2 30 27 0 vo lts
Z er o-Sig nal D-C Plate Cur rent [1]
43
Z er o-Sig nal D-C Plate Cur rent - 43 32 21 16 ma o
Z er o-Sig nal D-C Plate Cur rent [2]
32
Z er o-Sig nal D-C Plate Cur rent - 43 32 21 16 ma o
Z er o-Sig nal D-C Plate Cur rent [3]
21
Z er o-Sig nal D-C Plate Cur rent - 43 32 21 16 ma o
Z er o-Sig nal D-C Plate Cur rent [4]
16
Z er o-Sig nal D-C Plate Cur rent - 43 32 21 16 ma o
Max.- Sign a l D-C Plate Current [1]
13 mA
Max.- Sign a l D-C Plate Current - 13 3 120 94 80 ma o
Max.- Sign a l D-C Plate Current [2]
3 mA
Max.- Sign a l D-C Plate Current - 13 3 120 94 80 ma o
Max.- Sign a l D-C Plate Current [3]
120 mA
Max.- Sign a l D-C Plate Current - 13 3 120 94 80 ma o
Max.- Sign a l D-C Plate Current [4]
94 mA
Max.- Sign a l D-C Plate Current - 13 3 120 94 80 ma o
Max.- Sign a l D-C Plate Current [5]
80 mA
Max.- Sign a l D-C Plate Current - 13 3 120 94 80 ma o
Max. -Sig na l Driving Power (ap prox.) [1]
1.4 W
Max. -Sig na l Driving Power (ap prox.) - 1.4 1.2 0 .8 0 .7 watts
Max. -Sig na l Driving Power (ap prox.) [2]
1.2 W
Max. -Sig na l Driving Power (ap prox.) - 1.4 1.2 0 .8 0 .7 watts
Max. -Sig na l Driving Power (ap prox.) [3]
0 W
Max. -Sig na l Driving Power (ap prox.) - 1.4 1.2 0 .8 0 .7 watts
Max. -Sig na l Driving Power (ap prox.) [4]
8 W
Max. -Sig na l Driving Power (ap prox.) - 1.4 1.2 0 .8 0 .7 watts
Max. -Sig na l Driving Power (ap prox.) [5]
0 W
Max. -Sig na l Driving Power (ap prox.) - 1.4 1.2 0 .8 0 .7 watts
Max. -Sig na l Driving Power (ap prox.) [6]
7 W
Max. -Sig na l Driving Power (ap prox.) - 1.4 1.2 0 .8 0 .7 watts
Effecti ve Load , Plate -to-Pl ate [1]
9200
Effecti ve Load , Plate -to-Pl ate - 9200 15800 33 700 55500 ohms
Effecti ve Load , Plate -to-Pl ate [2]
15800
Effecti ve Load , Plate -to-Pl ate - 9200 15800 33 700 55500 ohms
Effecti ve Load , Plate -to-Pl ate [3]
33
Effecti ve Load , Plate -to-Pl ate - 9200 15800 33 700 55500 ohms
Effecti ve Load , Plate -to-Pl ate [4]
700
Effecti ve Load , Plate -to-Pl ate - 9200 15800 33 700 55500 ohms
Effecti ve Load , Plate -to-Pl ate [5]
55500
Effecti ve Load , Plate -to-Pl ate - 9200 15800 33 700 55500 ohms
Max. -Sig na l Plate Power Output [1]
50 W
Max. -Sig na l Plate Power Output 50 70 90 11 0 watts
Max. -Sig na l Plate Power Output [2]
70 W
Max. -Sig na l Plate Power Output 50 70 90 11 0 watts
Max. -Sig na l Plate Power Output [3]
90 W
Max. -Sig na l Plate Power Output 50 70 90 11 0 watts
Max. -Sig na l Plate Power Output [4]
11 W
Max. -Sig na l Plate Power Output 50 70 90 11 0 watts
Max. -Sig na l Plate Power Output [5]
0 W
Max. -Sig na l Plate Power Output 50 70 90 11 0 watts
D-C Plate Vo ltage [1]
1000
D-C Plate Vo ltage 1000 1500 2000 2000 volts
D-C Plate Vo ltage [2]
1500
D-C Plate Vo ltage 1000 1500 2000 2000 volts
D-C Plate Vo ltage [3]
2000
D-C Plate Vo ltage 1000 1500 2000 2000 volts
D-C Plate Vo ltage [4]
2000
D-C Plate Vo ltage 1000 1500 2000 2000 volts
D-C Plate Current [1]
72 mA
D-C Plate Current 72 67 63 75 ma o
D-C Plate Current [2]
67 mA
D-C Plate Current 72 67 63 75 ma o
D-C Plate Current [3]
63 mA
D-C Plate Current 72 67 63 75 ma o
D-C Plate Current [4]
75 mA
D-C Plate Current 72 67 63 75 ma o
D-C Grid Cu rrent [1]
9
D-C Grid Cu rrent 9 13 18 25 mao
D-C Grid Cu rrent [2]
13
D-C Grid Cu rrent 9 13 18 25 mao
D-C Grid Cu rrent [3]
18
D-C Grid Cu rrent 9 13 18 25 mao
D-C Grid Cu rrent [4]
25
D-C Grid Cu rrent 9 13 18 25 mao

Data set 02

1962 Eimac

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

Frequency for Maximum Ratings
-

Other

Maximum DC Plate Current
75 mA

Capacitance

Grid-Plate Capacitance
1.5 pF
Grid-Filament Capacitance
2.7 pF
Plate-Filament Capacitance
0.3 pF

Data set 03

1965 Eimac Tube Manual

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

The Eimac [1]
25 W
The Eimac 25T is a medium-mu, power triod® having a maximum plate dissipation of 25 wet+a
The Eimac [2]
25 W
The Eimac 25T is a medium-mu, power triod® having a maximum plate dissipation of 25 wet+a
Cooling of th
25
Cooling of th. 25T is accomplished by radiation from the plato, which op®ratos at a visible
Current
3 A
Current----- 3.0 amporos
D-C PLATE YOLT^ [1]
6
D-C PLATE YOLT^6E - - - '35 Volts
D-C PLATE YOLT^ [2]
35
D-C PLATE YOLT^6E - - - '35 Volts
MAX-S1 [1]
6 mA
MAX-S16NAL D-C PLATE CURRENT 75 MAX. MA.
MAX-S1 [2]
75 mA
MAX-S16NAL D-C PLATE CURRENT 75 MAX. MA.
PLATE DISSIPATION [1]
25 W
PLATE DISSIPATION ---- 25 MAX. WATTS ¥:ki;i:-iF,:o#,;a::,:n}jr;i:¥;%;;uP;O:Wup:o?we:.,.:ub.a: cO85 ':': !2! '12 Watts
PLATE DISSIPATION [2]
5 W
PLATE DISSIPATION ---- 25 MAX. WATTS ¥:ki;i:-iF,:o#,;a::,:n}jr;i:¥;%;;uP;O:Wup:o?we:.,.:ub.a: cO85 ':': !2! '12 Watts
PLATE DISSIPATION [3]
2 W
PLATE DISSIPATION ---- 25 MAX. WATTS ¥:ki;i:-iF,:o#,;a::,:n}jr;i:¥;%;;uP;O:Wup:o?we:.,.:ub.a: cO85 ':': !2! '12 Watts
PLATE DISSIPATION [4]
12 W
PLATE DISSIPATION ---- 25 MAX. WATTS ¥:ki;i:-iF,:o#,;a::,:n}jr;i:¥;%;;uP;O:Wup:o?we:.,.:ub.a: cO85 ':': !2! '12 Watts
GRID DISSIP^TION
7 mA
GRID DISSIP^TION ---- 7 MAX. WATTS 'Adiust to give stated zero-signal plate current.
D-C PLATE CullENT
60
D-C PLATE CullENT ----- 60 MAX. MA.
D-C pl^TE YOLT^ [1]
6 W
D-C pl^TE YOLT^6E ---.- 2000 MAX. VOLTS Grid Dissipation - -
D-C pl^TE YOLT^ [2]
2000 W
D-C pl^TE YOLT^6E ---.- 2000 MAX. VOLTS Grid Dissipation - -
D-C PLATE CuRRENT
75 mA
D-C PLATE CuRRENT ----- 75 MAX. MA.
PLATE DISSIP^TION
25
PLATE DISSIP^TION -..--- 25 MAX. WATTS
GRID DISSIP^tloN
7
GRID DISSIP^tloN --..-- 7 MAX. WATTS allow for variations in circuit losses.
power output and grid driving power [1]
70 W
power output and grid driving power 70 -75
power output and grid driving power [2]
-75 W
power output and grid driving power 70 -75
at plate voltages of [1]
10001500 V
at plate voltages of 1000,1500 and Pp E20 cO -65
at plate voltages of [2]
0 V
at plate voltages of 1000,1500 and Pp E20 cO -65
at plate voltages of [3]
-65 V
at plate voltages of 1000,1500 and Pp E20 cO -65
POWER
0 W
POWER 0 U T P UT AT T S POWEP OUTPUT-WATTS