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Introduction

Trying to identify an unknown valve that lacks identification is a problem we all have, especially with all glass valves where the paint is easy to rub off.

To make a specific parameter search using the standard museum search program of Zoom Indexer some special encoding has been used. A little tedious at first - but very powerful in use.

Some valves, especially those with the International Octal base cap, have pins omitted where they are not used. Within the museum these are universally recorded as nc for no connection. Those pins connected internally that must not have an external connection are recorded as ic.

Identifying an Unknown Valve

Each major parameter type is prefixed e.g. valve shape has the prefix shape: to make the search look for the parameter as a complete word spaces and hyphens have been replaced by full points . also the / is replaced with .

A very useful feature is the ability to search by pin connection. e.g. pin:1.a etc.

By searching for the valve.base and all of the pin connections the pin compatible types can be found as an aid to initial location of possible substitutes.

By recording the search terms in a text file they can be copied and pasted into the search box to avoid repeat typing.

Some examples

By searching for the EL84 B9A base and pin connections the pin compatible types are found.
base:b9a pin:1.ic pin:2.g1 pin:3.k.g3 pin:4.h pin:5.h pin:6.ic pin:7.a pin:8.ic pin:9.g2
returns: 6BQ5, 6P15, 30P12, CV5094, EL84, EL86, N709, PL84, UL84.

PX4

The full parameters recorded for the PX4 are:
shape:classic construction:pinch type:triode age:1920.1930 base:b4 heater:4.0v pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f

KT66

The full parameters recorded for the KT66 are:
shape:classic construction:pinch type:beam tetrode age:1930.1940 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a pin:4.g2 pin:5.g1 pin:6.nc pin:7.h pin:8.k.bp

EL34

The full parameters recorded for the EL34 are:
shape:wide.glass.tube construction:glass.foot type:pentode age:1950.1960 base:io heater:6.3v pins:8 pin:1.g3 pin:2.h pin:3.a pin:4.g2 pin:5.g1 pin:6.nc pin:7.h pin:8.k

EL84

The full parameters recorded for the EL84 are:
shape:thin.glass.tube construction:all.glass type:pentode age:1950.1960 base:b9a heater:6.3v pins:9 pin:1.ic pin:2.g1 pin:3.k.g3 pin:4.h pin:5.h pin:6.ic pin:7.a pin:8.ic pin:9.g2

ECC83

The full parameters recorded for the ECC83 are:
shape:thin.glass.tube construction:all.glass type:double.triode age:1950.1960 base:b9a heater:6.3v pins:9 pin:1.a pin:2.g1 pin:3.k pin:4.h pin:5.h pin:6.a pin:7.g1 pin:8.k pin:9.hct

GZ34

The full parameters recorded for the GZ34 are:
shape:wide.glass.tube construction:glass.foot type:rectifier.fw age:1950.1960 base:io heater:5.0v pins:8 pin:1.m pin:2.h pin:3.nc pin:4.a pin:5.nc pin:6.a pin:7.nc pin:8.h.k
Pins 3,5 & 7 are omitted.

Full list of Recorded Parameters

For explanations and exhibits matching any parameters the classified indexes can be found here.

All details below are case sensitive. The information has to be entered in the search box exactly as given below.

Nearly all base designs have explanation pages located on the right hand menu of the appropriate base index page.
The common and clear glass base types have direct links in the table.