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Tube Tinker — Electron Tube Database

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6BL8 alternatives, equivalents, and replacements

Review exact electrical variations and directional substitutions recorded for the 6BL8 voltage radio detector converter. Compare core specifications and verify every restriction before using a replacement.

Exact variations of 6BL8

These designations belong to the same electrical variation group. Their names may differ because of international standards, manufacturing tolerances, or materials, but they are recorded as electrically equivalent—not merely substitutes.

  • 6LN8

    Voltage Radio Detector Converter

    Base
    9DC
    Socket
    B9A
    Base pins
    9
    Sections
    2
    Heater voltage
    6 V
    Heater current
    0.45 A
  • ECF80

    Voltage Triode Pentode

    Base
    9C12
    Socket
    B9A
    Base pins
    9
    Sections
    2
    Heater voltage
    6.3 V
    Heater current
    0.43 A

Replacement tubes for 6BL8

The following tubes are recorded as possible replacements for 6BL8. This direction does not establish that 6BL8 can replace them.

E80CF

Voltage Triode Pentode

Foreign To American

The database records E80CF as a possible replacement for6BL8.

  • Parallel heater circuits only
SpecificationOriginal tubeReplacement
Tube typeVoltage Radio Detector ConverterVoltage Triode Pentode
ConstructionPentode-TriodePentode-Triode
Base9DCNOVAL
SocketB9AB9A
Base pins99
Sections22
Heater voltage6.3 V6.3 V
Heater current0.45 A0.33 A
ECF80

Voltage Triode Pentode

Foreign To American

The database records ECF80 as a possible replacement for6BL8.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage Radio Detector ConverterVoltage Triode Pentode
ConstructionPentode-TriodePentode-Triode
Base9DC9C12
SocketB9AB9A
Base pins99
Sections22
Heater voltage6.3 V6.3 V
Heater current0.45 A0.43 A
7643

Voltage Radio Detector Converter

Receiving To Industrial Tubes

The database records 7643 as a possible replacement for6BL8.

  • Parallel heater circuits only
SpecificationOriginal tubeReplacement
Tube typeVoltage Radio Detector ConverterVoltage Radio Detector Converter
ConstructionPentode-TriodePentode-Triode
Base9DCNot recorded
SocketB9AB9A
Base pins99
Sections22
Heater voltage6.3 V6.3 V
Heater current0.45 A0.33 A
6LN8

Voltage Radio Detector Converter

Receiving Tubes

The database records 6LN8 as a possible replacement for6BL8.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage Radio Detector ConverterVoltage Radio Detector Converter
ConstructionPentode-TriodePentode-Triode
Base9DC9DC
SocketB9AB9A
Base pins99
Sections22
Heater voltage6.3 V6 V
Heater current0.45 A0.45 A

Where 6BL8 can be used as the replacement

In these recorded relationships, 6BL8 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6BL8.

ECF80

Voltage Triode Pentode

American To Foreign

The database records 6BL8 as a possible replacement forECF80.

No special restrictions are recorded for this substitution.

Specification6BL8 replacementOriginal tube
Tube typeVoltage Radio Detector ConverterVoltage Triode Pentode
ConstructionPentode-TriodePentode-Triode
Base9DC9C12
SocketB9AB9A
Base pins99
Sections22
Heater voltage6.3 V6.3 V
Heater current0.45 A0.43 A
6HL8

Voltage Triode Pentode

Receiving Tubes

The database records 6BL8 as a possible replacement for6HL8.

  • Parallel heater circuits only
Specification6BL8 replacementOriginal tube
Tube typeVoltage Radio Detector ConverterVoltage Triode Pentode
ConstructionPentode-TriodePentode-Triode
Base9DC9AE
SocketB9AB9A
Base pins99
Sections22
Heater voltage6.3 V6.3 V
Heater current0.45 A0.6 A
6LN8

Voltage Radio Detector Converter

Receiving Tubes

The database records 6BL8 as a possible replacement for6LN8.

  • Parallel heater circuits only
  • No-warmup series circuits only
Specification6BL8 replacementOriginal tube
Tube typeVoltage Radio Detector ConverterVoltage Radio Detector Converter
ConstructionPentode-TriodePentode-Triode
Base9DC9DC
SocketB9AB9A
Base pins99
Sections22
Heater voltage6.3 V6 V
Heater current0.45 A0.45 A

Verify before substituting

Matching a base or heater voltage is not enough to prove that two tubes are interchangeable. Check pin connections, heater current, maximum ratings, bias requirements, warm-up behavior, and the equipment manufacturer’s service documentation before making a substitution.

View the complete 6BL8 specifications →