Radio Valve Data: 1915-1960

Keith R Thrower OBE, The Valve Museum, April, 2022.

Triode Receiver Valves (pre-1926)^*

Type or
Trademark

Filament

Anode

Grid

r_a

g_m

μ

Year

Base

Notes
and applications

^{(1)The letters indicate the three types of filaments found on these valves. B = bright emitter, D = dull emitter, O = oxide-coated.}

Volts

Amps

Volts

-Volts

kΩ

mA/V

^{(2)The year shown is when it is believed the type was first issued. This date is accurate for most types but cannot be guaranteed for them all.}

^{(3)Pin-out details for non-exhibits can be found with the base details.}

  ^{★This table lists valves that were manufactured in the UK or which were claimed to be of UK manufacture. In practice several of the smaller companies imported their valves from abroad.}

 Dextraudion

235 (2V GP)

D

2.0

0.35

25-100

3.0

21.0

0.31

6.5

1925

B4

General purpose

240 (2V LF)

D

2.0

0.40

20-100

4.5

18.0

0.39

7.0

1925

B4

AF amp./output

306 (3V GP)

D

3.0

0.06

25-100

3.0

20.0

0.28

5.5

1925

B4

General purpose

312 (3V LF)

D

3.0

0.12

60-120

4.5

18.0

0.42

7.5

1925

B4

AF amp./output

406 (4V GP)

D

4.0

0.06

60-120

3.0

21.0

0.29

6.0

1925

B4

General purpose

412 (4V LF)

D

4.0

0.12

50-100

4.5

18.0

0.42

7.5

1925

B4

AF amp./output

440 (4V GP)

D

4.0

0.40

30-100

30.0

0.40

12.0

1925

B4

General purpose

530 (5V LF)

D

5.0

0.30

50-100

10.0

0.75

7.5

1925

B4

Output

Dextraudion

D

0.8-1.1

0.15

30-60

30.0

0.25

7.4

1924

B4

General purpose