GUIDE TO DETERMINING RADIO TUBE BASES

Just N. Qvigstad  LA9DL

v.0.03 (02.02.2023)

This web-page is a help to determine a tubes base type. In manufacturers' tube documentation, the tube bases are often difficult to decipher, picture is missing, measurements often in a separate table and far too much unnecessary information on the base diagrams whitch them difficult to read.. Therefore, the majority of base diagrams are redrawn in a gray scale and only needed measurements for base type decision. Since tolerance measures have been dropped, one must take into account that all measures are nominal. Octal and sub-miniature tubes have many varieties. Therefore, the Octal tubes are divided into subgroups and the sub-miniature tubes (tube diameter less than 12 mm) are sorted by the diameter of the tube (T-1 to T-3) and not by count of pins/wires,

Base with contact pins:

1-PIN:

2-PIN:
Base 16mm
Base 16x22mm
All glass
Medium shell
Pencil
Base with window
Base B2A
Base twist lock

3-PIN:
Philips 4mm pins
Philips 6mm pins
Blade base
Arcotron
PeeWee
De-Forest US Navy
Europe B3
In-Line B3G
Base B15A3
Base LK121
Base WE 212A
Big TX Base
Base Ediswan
Base Telefunken
3-pin base /1-Socket Telefunken

4-PIN:
Franko-British
Europe
Europe side terminals
Base UV199
Base UV
Dwarf shell US

Tapered shell US
Small Shell US
Metal Shell US
Medium Shell US
Medium metal shell with bayonet US
Medium shell with bayonet US
Skirted medium metal shell with bayonet US
Jumbo short metal shell
Jumbo medium metal skirted shell, Type 1, Type 2, Type 3
Jumbo medium metal shell
Jumbo large ventilated metal shell
Super Jumbo small shell
Super Jumbo medium shell
Super Jumbo medium metal shell
Super Jumbo large metal shell with bayonet
Medium ceramic disk US B4A
Super Giant
Giant metal shell with bayonet
British L4
Philips big W4
Philips Telefunken BC4
EMI Cossor CRT B4E
Midget Hivac
Mini base Telefunken
Telefunken bayonet
Base WD
4-pin /1 Socket Telefunken
Large base 211 WE
Large base 212 WE
Base 316A
Base 703A
Base mettal 415 WE

5-PIN:
Miniature USSR
Telephone EU
French base
French Bi-grille
French Bi-Grille with side-terminal
French base PTT210
Midget Hivac
Small shell US
Medium shell US
Wide shell with barrier US
Giant base
Giant medium shell with bayonet
Giant metal shell with ventilated base
Super Giant
Super Giant metal base
Super Giant metal base with 3.keys
Telefunken bayonet

6-PIN:
Europe
Continutal EU
French Tri-Grille
Small shell US
Medium shell US
Medium long shell US
Siemens
Loewe bayonet bayonets
Loewe with senter-contact and bayonets

7-PIN:
Miniature
Miniature with pumping stem
Mini-miniature
Telephone
British B7
Continental EU
French Bi-Grille
Small shell US
Medium shell US
Medium shell with bayonet
US Septar medium molded flare
Septal medium button
Septar small wafer
Septar large button
Septar jumbo button
Giant medium metal shell with bayonet
Giant ventilated metal shell
All glass 2+5 pins

8-PIN OCTAL

8-PIN LOCTAL
Lock-in US
Loctal medium continental EU
Loctal large plastic spigot EU
Loctal large EU
Loctal TX

8-PIN:(not Octal)
Ditetrar with small button tip
Super Ditetrar with small button tip
Neo-Ditetrar
Eightar
Neo-Eightar
German medium shell Y8A
German short medium shell Y8A
German ultra short medium shell Y8A
German medium wafer Y8A
German large wafer Y8A
Rimlock metal shell
Rimlock glass wafer
Rimlock all glass
Rimlock metal shell spigot
All glass light base spigot
Gnom base

9-PIN LOCTAL:
Standard base
Big base
Plastic-spigot
Mica disc
Small base

10-PIN:
Decal
Decar
German Y10A with Large wafer
German Y10A  with Flared shell
Telefunken All glass CRT
Telefunken G10G
2+8pin Loctal

11-PIN:
Gnom base
Elevenar large wafer
Magnal small shell
Magnal medium shell
Sub-Magnal small shelll
Neo-Submagnal small shell                   
Unidecar small button
Special shoulder CRT
Indicating tube base
Large Nuvistor

12-PIN:
Indicating tube oval base
All-glass B12F
Duodecal small shell
Duodecal dwarf shell
Duodecar ultra short small shell
Duodecar short small shell
Duodecar base cap
Duodakar small buttom (Compatron)
Duodakar large buttom (Compatron)
CRT B12B
Twelvar medium ceramic wafer (Nuvistor)
Loewe base

13-PIN:
All-glass B13B
Thirteenar small button

14-PIN:
All-glass bottom with glass tip
All glass with short spigot
All glass long spigot
Diheptal B14A small shell
Diheptal B14A medium shell
Neo-Diheptal B14F
Miniature
14/15-pin Sub-miniature
Indicating tube - oval base

15-PIN:
All glass
All glass B13B

16-PIN:
All-glass WE

16-PIN:
All-glass B17A

20-PIN:
All-glass

21-PIN:
All-glass

25-PIN:
Special base 15+10 pin

26-27-PIN:
Special all-glass

29-PIN:
Twentyfyninar

35-PIN:
Thirtyfivar

Side pins (Acorn):
4-pin Acorn
5-pin Acorn 5AA
5-pin Acorn 7AA
5-pin Acorn wide P7A
7-pin Acorn Fivre
7-pin Acorn 7AB
7-pin Acorn P7
12-pin Acorn

SIDE-CONTACT::
4-side contact British B4E
4-side contact SCA Base
4-side contact small pins
5-side contact Continental EU
8-side contact Continental EU
12-side contact CRT B12D
12-side contact CRT P12
13-side contact CRT B13D
18-side contact CRT

SUB-MINIATURE WITH PINS:
T-3 pin tube:
8-pin round base

T-3x2 pin tube:
4-pin press base
5-pin press base

SUB-MINIATURE WITH WIRES:
T-1 wired tube round base:
4-wire round base
5-wire round base

T-1.5 wired tube press base:
4-wire press base

T-1.5 wired tube round base:
5-wire round base

T-1.5x2 wired tube press base:
6-wire press base

T-2 wired tube press base:
3-wire press base
4-wire press base
5-wire press base

T-2 wired tube round base:
5-wire round base center wire

T-2 wired tube special base:
3.wire special base
5.wire special base

T-3 wired tube round press base :
2-wire press base
3-wire press base
4-wire press base
5-wire press base
6.wire press base
7.wire press base

T-3 wired tube round base:
2-wire round base with tip
6-wire special round base

T-3x2 tube press base:
2-wire press base
5-wire press base
7-wire press base

T-3.5 wired tube special base:
2-wire round base with tip
3-wire round base with tip

STRAP/WIRE BASE:
7-straps Miniature base
10-straps Loctal base
7-wiire Miniature base
2-semiflexible leads
12/13-leads Thirteennar
14-wire Miniature

CLIP CONTACT:
3-clip, 6-clip, 7-clip, 11-clip

SOCKET CONTACT:
3-socket German base Ø: 66mm
3-socket German base Ø: 82mm
4-socket German base Ø: 66mm

BAYONET CONTACT:

B10, B15, B22, B27

SCREW CONTACT:

E10, E12, E14, E27, E40

COAXIAL BASE:
4.contact coaxial
4.contact disk seal

BLADE / CAP / STRIP / NUB CONTACT:
2-blade contact large
2-blade contact small
2-cap contact Ø15mm
2.strap 23mm wide
2-strap 35mm wide
2-contact strip and pin Type 1
2-contact strip and pin Type 2
2-nub base
4-nub peanut