Smooth Long Plate Telefunken ECC83 12AX7 tube. AT1000 Tested 106% & 118% gm

All of the labeling is worn off on this tube. 

This tube clearly has the Telefunken diamond on the bottom.

Before testing the heater was on for at least 2 minutes and plate voltage was applied for at least on minute.

Also checked for shorts, noise, and microphonics.

Tube was tested in Fixed Bias mode

Was tested on a Amplitrex AT100.  One of this tester's attributes is detecting gas.  Any low level gas the AT1000 detects, it is likely other testers will not measure any gas at all.

The Transconductance spec for a new tube is 1600 mhos at 250 plate volts. 

Amplitrex AT1000 results.

Tube             Emissions % GM %        mhos        H-K leakage ua   Gas mA

ECC83 12AX7       116/141     106/118     1700/1900   0/0               .0/.0

The gas value above is well within the good range.  The tester manual says for signal tubes the gas ma should be less than 1ma.

These are well below 1ma.

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