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Tube Tinker — Electron Tube Database

Tube cross-reference

PY81 alternatives, equivalents, and replacements

Review exact electrical variations and directional substitutions recorded for the PY81 rectifier - damper diode. Compare core specifications and verify every restriction before using a replacement.

Exact variations of PY81

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.

  • 17Z3

    Rectifier - Damper Diode

    Base
    9CB
    Socket
    B9A
    Base pins
    9
    Sections
    1
    Heater voltage
    17 V
    Heater current
    0.3 A
  • PY83

    Rectifier - Damper Diode

    Base
    Not recorded
    Socket
    B9A
    Base pins
    Not recorded
    Sections
    1
    Heater voltage
    20 V
    Heater current
    0.3 A

Replacement tubes for PY81

The following tubes are recorded as possible replacements for PY81. This direction does not establish that PY81 can replace them.

17Z3

Rectifier - Damper Diode

American To Foreign

The database records 17Z3 as a possible replacement forPY81.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeRectifier - Damper DiodeRectifier - Damper Diode
ConstructionRectifierRectifier
BaseNot recorded9CB
SocketB9AB9A
Base pins99
Sections11
Heater voltage17 V17 V
Heater current0.3 A0.3 A

Where PY81 can be used as the replacement

In these recorded relationships, PY81 is the replacement tube. The listed original tubes are not automatically suitable as replacements for PY81.

17Z3

Rectifier - Damper Diode

Foreign To American

The database records PY81 as a possible replacement for17Z3.

No special restrictions are recorded for this substitution.

SpecificationPY81 replacementOriginal tube
Tube typeRectifier - Damper DiodeRectifier - Damper Diode
ConstructionRectifierRectifier
BaseNot recorded9CB
SocketB9AB9A
Base pins99
Sections11
Heater voltage17 V17 V
Heater current0.3 A0.3 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 PY81 specifications →