My tube tester — L3-3

[Raffi]

Hi everyone! I want to tell in this thread about my tube tester L3-3. I will start with the fact that among engineers who deal with tubes, this tester is considered one of the best in the world! My tester L3-3 was made in 1976 - one of the best releases among these devices. This copy was made in Minsk factory "Kalibr" (Belarus), which existed until 2019. The tester has undergone a small modernization, I replaced most of the non-polar capacitors in it with quality capacitors from Wima, Mallory and so on....

In L3-3 unlike its predecessor - L1-3 in the power supply vacuum stabilitrons have been replaced by semiconductor ones. 

This tester allows you to check a large number of lamps, not only Soviet, and if you make adapters for some bases, the list of tested lamps will increase even more.

 

This tester measures the following parameters in radio lamps:

 

In diodes:

 

- Emission current or anode current;

 

In triodes, double triodes, tetrodes, pentodes and combination lamps:

 

- anode current;

 

- second grid current;

 

- the reverse current of the first grid;

 

- steepness of the anode current characteristic:

 

- the steepness of the characteristic of the heterodyne part of frequency-converting tubes;

 

- anode current at the beginning of the characteristic or grid locking voltage;

 

In gas discharge voltage stabilizers:

 

- ignition potential;

 

- stabilization voltage;

 

- change in stabilization voltage with changing current;

 

In kenotrons:

 

- Rectified current when fed from a 50 Hz mains supply.

 

 

 

Also in all types of lamps:

 

- leakage current between the cathode and the heater at voltages of 100 and 250 V (plus on the cathode, minus on the heater);

 

- leakage current between the electrodes (cathode and grid one, grid one and grid two) at voltages of 100 and 250 V.

 

The device provides supply of the following voltages to the electrodes of tested lamps:

 

 

on the incandescent - from 1 to 14 V at a current of 1.2 A;

 

on grid 1 - 0, from -0.5 to 65 V and fixed voltage -100 V;

 

on grid 2 - from 10 to 300 V at current up to 15 mA;

 

on anode - from 5 to 300 V at current up to 100 mA;

 

variable voltages for tested kenotrons - 2x350, 2x400, 2x500 V.

This instrument helps me a lot, I use it a lot, always before selling new NOS tubes I measure them on this tester. I also use it to select tubes for my amplifiers and provide testing services

 

I do not exclude that it is possible to sell and deliver abroad the same devices from Russia.

 

Also, if anyone needs a radio lamp test, you can message me.

 

Thanks for reading!