Probadores de Tubos (Tube Testers)

[hectori 761]

asi es un forero compro uno!! duro un par de semanas y fallo la eprom ,el fabricante no da soporte tecnico no puedo negar que la maquina era muy practica!! pero en definitiva las antiguas son de lo mejor

No da soporte?? y que pasó? ahi murió? Perdida total?
Usá las partes principales y adaptás el sistema de los Probadores DIY, hay varios proyectos...

[striker 87]

Quedo en el baul de los recuerdos jeje

[hectori 761]

Uhh q pena, bueno si lo quiere sacar del baul, que me avise.... Seria bueno ver que se puede hacer con ese probador.

[hectori 761]

Vintage

[hectori 761]

TESLA BM215A - Otro Cardmatic

[hectori 761]

Probador de tubos IBM

[hectori 761]

Otros Probadores de Tubos Europeos

Windsor


Taylor



Mullard

[hectori 761]

Mientras espero ver como edito las fotos de los otros posts, les dejo otras fotos de Probadores PRO :) En este caso el mas completo de los probadores RCA, en un estado increíble, se vendió en Ebay hace unos meses en mas de 1700 usd si mal no recuerdo.

 

[hectori 761]

Otros

[rrohland 1.183]

Aquí, un par de fotitos de mi humilde Eico 667:

 

 

Aunque yo aún no lo destripo, así debería verse por dentro:

 

El manual, con todas las características del equipo: http://diyaudioprojects.com/Testeq/EICO-667/EICO-667-Tube-Tester-Instructions-Manual.pdf

Y el listado grandote de tubos que se pueden probar y sus respectivas configuraciones: http://diyaudioprojects.com/Testeq/EICO-667/Tube-Data-EICO-667-Tube-Tester.pdf

 

[hectori 761]

On 9/16/2018 at 8:19, rrohland dijo:

Aquí, un par de fotitos de mi humilde Eico 667:

 

 

Aunque yo aún no lo destripo, así debería verse por dentro:

 

El manual, con todas las características del equipo: http://diyaudioprojects.com/Testeq/EICO-667/EICO-667-Tube-Tester-Instructions-Manual.pdf

Y el listado grandote de tubos que se pueden probar y sus respectivas configuraciones: http://diyaudioprojects.com/Testeq/EICO-667/Tube-Data-EICO-667-Tube-Tester.pdf

 

Ese Eico es muy bueno, te dejo el Excel con los datos de prueba de distintos tubos : http://conradhoffman.com/EicoTubeTesterSettings.xls

[rrohland 1.183]

hace 5 horas, hectori dijo:

Ese Eico es muy bueno, te dejo el Excel con los datos de prueba de distintos tubos : http://conradhoffman.com/EicoTubeTesterSettings.xls

Gracias ché!!! Excelente aporte 

[bavario 298]

Alguien podría desarrollar un probador con electrónica moderna con software para modelo de tubo que sea “plug and play”, la tecnología para hacerlo barato está.

[pacifyer 100.000]

hace 33 minutos, bavario dijo:

Alguien podría desarrollar un probador con electrónica moderna con software para modelo de tubo que sea “plug and play”, la tecnología para hacerlo barato está.

Algunos testers y trazadores. Ignoro si sirven:

http://www.jacmusic.com/Tube-testers/Amplitrex/index.htm

http://www.jacmusic.com/Tube-testers/Sofia/Sofia-Index.htm

http://www.maximatcher.com/

http://amplitrex.com/

http://www.thebestamp.com/Testing_Equipment/Easy-Tube-Tester2.php

http://lnx.lv/lnx_tracer/

http://www.sgitheach.org.uk/crttester1.html

http://www.roehrentest.de/EnglishInfo.html

http://www.canor-audio.com/?p=901

http://tubesontheweb.com/matic.htm

http://www.klausmobile.narod.ru/projects/pr_02_kmtt_e.htm

https://retrovoltage.com/tag/digital-tube-tester/

http://www.valvewizard.co.uk/curvetracer.html

 

 

[hectori 761]

1 hour ago, bavario dijo:

Alguien podría desarrollar un probador con electrónica moderna con software para modelo de tubo que sea “plug and play”, la tecnología para hacerlo barato está.

Ya Existen, de hecho hay varias marcas (algunas ya las dejó pacy en su post) uno de los mas basicos y simples es este en ebay

https://www.ebay.com/itm/Vacuum-tube-tester-Digital-LCD-tester-KIT/161942329443?hash=item25b483d863:g:vRUAAOSwJkJWkbmo

[pacifyer 100.000]

hace 11 minutos, hectori dijo:

Ya Existen, de hecho hay varias marcas (algunas ya las dejó pacy en su post) uno de los mas basicos y simples es este en ebay

https://www.ebay.com/itm/Vacuum-tube-tester-Digital-LCD-tester-KIT/161942329443?hash=item25b483d863:g:vRUAAOSwJkJWkbmo

 

Lo que no me quedó claro es dónde te la enchufo. 

 

 

 

 

 

PD: a la válvula

[hectori 761]

http://lampizator.eu/UPGRADE/tubetester/tube%20tester.html

Lampizator tiene una versión Simple, pero sin Pantallita,

[hectori 761]

hace 9 minutos, pacifyer dijo:

 

Lo que no me quedó claro es dónde te la enchufo. 

 

 

 

 

 

PD: a la válvula

Tiene 4 cables listos para soldar a las bases de los tubos a probar.

 

De todas formas, tené cuidado, si lo enchufas al dildo, se te va a quemar...  ese es el "Tubo" que queres "Probar"? 

[pacifyer 100.000]

hace 5 minutos, hectori dijo:

Tiene 4 cables listos para soldar a las bases de los tubos a probar.

 

De todas formas, tené cuidado, si lo enchufas al dildo, se te va a quemar...  ese es el "Tubo" que queres "Probar"? 

Muéstreme cómo conecto esta custión:

o esta otra:

 

[hectori 761]

Getting started is very simple, because most of the elements are already connected.  You only need to plug the different connectors , followed by the T1 and T2 to the mains  using a switch and a fuse 1A.

 

Connect the four wires (cathode, G2, plate and G1) to the appropriate tube socket pins.  Do not forget to slide the ferrite beads on to the wires (except for the cathode).

 

Connect a transformer or an appropriate power supply to the tube’s filament socket.

 

Make sure that the module is on an insulated support and that there is no short circuit that can possibly occur.  Switch on power.

 

Pre-adjust the V plate voltage (Plate), Vg2 (grid 2)*, and Vg1 (grid 1) according to the characteristics of the tube to be tested.

 

 

Example of measurement :  

 

EL84 tube, the datasheet indicates :

 

 

Pin 2 :  G1 (grid 1)

 

Pin 3 :  K-G3 (cathode and grid 3)

 

Pin 4 : F (filament)

 

Pin 5 : F'(filament)

 

Pin 7 : A (anode and plate)

 

Pin 9 : G2 (screen or grid 2)

 

 

Test conditions :  In the absence of indications just refer to the curves.  According to these curves, it would be possible, for instance, to choose a plate voltage of 300V, a G2 voltage of 250V and a G1 voltage of -4.0V.  Under these conditions, the nominal debit would be 90 mA.

 

1 Set the display voltage selector as to show the plate voltage.

2 Turn the Vplate potentiometer to get a 300V reading on the screen.

3 Set the display voltage selector as to show the G2 voltage.

4 Turn the Vg2 potentiometer to get a 250V reading on the screen.

5 Turn the Vg1 potentiometer to get a -4.0V reading on the screen.

6 Plug the tube and leave it to heat up for about one (1) minute.

 

*Choose the corresponding displays by using the voltage switch.

 

Check that the neon indicator is turned off or is blinking.  For certain tubes, this light could be turned on continuously without blinking even if there is no short circuit.  In general , this kind of phenomenon is created by tubes which have high transconductance or power or by valves and cathodic indicators.

 

It is not dangerous to carry out tests even if the light is turned on.

 

Push on the "TEST" button and read the value of the plate current in mA.

 

· Release the button.  The test is completed.

 

More measurements :  transconductance , internal resistance and gain are possible and simple.  

 

 

Tubes matching is done by a simple method.  Test several tubes of the same type without changing the adjustments in order to pair up (or in quartets) tubes with plate currents whose measurements are closest.

 

For double tubes like : ecc81, ecc82, ecc83, ecc88 – 6sl7, 6sn7, etc…The measurement of any of the internal triodes can be undertaken by swaping the connection to either  the plateof triode 1 or triode 2 ( all other same electrodes connected together ). This can be easily undertaken with a simple inverter.

 

 

The testing of valves, diodes , cathodic indicators, gas regulators  is possible and described on §6.

 

 

 

2 OPERATING PRINCIPLES

 

 

 

Using an impulse mode, the tests are carried out every 0.5 seconds.  The time lag for obtaining the results is very short :  800 uS (0.0008 seconds).

 

Between the test windows, grid 1 is at a negative potential and the tube is in a cut-off state.  Its dissipation is almost non-existent.

 

This mode allows for the use of very little energy on the high voltage supply (plate and G2), and prevents the use of heavy and costly transformers, while at the same time allows for tests using high voltage and plate current (450V / 340mA).

 

A microcomputer PIC clocked at 12MHz carries out the acquisiton , measurement and management of defects and of the commands for the LCD display.

 

The plate supply is organised around an self-oscillation converter (Royer) controlled by a comparator.  A high-value condenser (47µF) serves as a reservoir and supplies the voltage during the800µS  test.  This condenser discharges slowly.  When the plate voltage has to be lowered, through the Vplate potentiometer, it would be useful to briefly push the DISCHARGE button, which would put a discharge resistance in parallel with the supply output and accelerate the process.  SURCHARGE warning (see below)   could then be displayed, and will disapear when the button is released.

 

The G2 supply, which has a lower debit, is organized around a conventional circuit :  transformer, rectifier, filter, stabilization using a group of zener diodes.  A power mosfet controlled by the Vg2 potentiometer delivers the G2 voltage.

 

These two supplies, plate and G2, are protected by current limiters. The peripheral circuits also have this type of protection.

 

The display of the plate and G2 voltage is carried out in an alternating manner through selection, using the voltage switch (connector J1 - pins 4, 5 and 6).  The G1 supply circuitry is like G2 but because of the low current, it is not buffered.

 

A short circuit tester for the plate and the internal electrodes of the tube is effected through a neon light (connector J2, pins 8 and 10). This neon lights up continuously in the event of a strong current.  Otherwise, it will blink or will remain extinguished.  This simple circuit is just an aide for the tests and has its limits.  It could stay lighted up continously when used with high power tubes or tubes of a specific type (diodes, magic eyes…) are present.

 

Some tubes are very unstable and the connection wires can be seen as resonant circuits.  Likewise, the plate, G2 and G1 wires have to be equipped with a ferrite bead filter to block any possible auto-oscillation.  These beads have to be positioned beside the tube socket closest to the connections.

 

The microcomputer monitors the plate voltage current. All excess will automatically limit the output voltage, SURCHARGE will appear on the screen, and all tests will be suspended until the problem disappears or until the TEST button is released.

 

 

 

3 ADVANCED TESTS

 

 

 

The cathodic current of a tube is an important element to determine its state and to carry out matching.

 

Nonetheless, this parameter gives only a preview of the tube overall performance.  With the DuoKit you will be able to carry out three other very complementary tests, which are :

 

 

 

· The slope or transconductance : Gm :  expressed in mA/V, uS or umhos

 

· The internal resistance Rp :  expressed in Ohm

 

· The gain µ which is the result of the two preceding values

 

 

 

Testing the slope :

 

 

Carry out a first test, and note the corresponding cathode current Ik1.

 

Without making other adjustments, increase or decrease the voltage on grid 1 (Vg1) by one volt, and note the new cathode current Ik2.

 

The Gm ( transconductance ) is the difference between the lk1 and lk2 currents, expressed in mA / V, or in uS, or in umhos, by multiplying the value by 1000 : 1mA/V = 1000 uS = 1000 umhos.

 

This feature, measured on several points, enables one to know the linearity of a tube.

 

Testing internal resistance :

 

Carry out an initial test, note the Vp1 plate voltage and the corresponding lk1 current.

 

Without making other adjustments, increase or decrease the plate voltage (Vplate) until a significant change in the current is created.  Note the new value of the Vp2 plate voltage and the new lk2 current.

 

The internal resistance Rp is the difference of the plate voltage divided by the difference of the corresponding currents :  Vp1 - Vp2 divided by Ik1 – Ik2

 

Calculating the gain :

 

As indicated above, the µ gain is equal to Gm (in mA/V) x Rp

 

All tube features are then known, and a very precise matching can thus be made.

 

 

 

4 VALVES, REGULATORS AND CATHODIC INDICATORS

 

 

 

Testing particular tubes like diodes, valves, rectifiers, gas-regulated tubes and cathodic indicators can be done with the DuoKit.

 

Diodes :

 

With the internal module supply, low-power tubes can be tested to a maximum current of approximately 15 mA,.  For currents above this, follow the procedure for valves testing.

 

Before plugging the tube, turn the Vplate potentiometer fully anti-clockwise and, if needed, push the DISCHARGE button several times to bring the plate voltage to a value < 5 volts.

 

The connection is done similarly as for other tubes :  wire K to the cathode and the Plate wire towards the plate (s).

 

When the tube is hot, slowly turn the Vplate potentiometer and observe the increase of the current, comparing it to the curve presented in the tube specifications.

 

Valves :

 

Valves or rectifiers tubes can be partially tested with an internal plate supply of the module.  However, the absence of the command grid prevents the  operation of the impulse mode, and the permanent debit may exceed the capacity of this supply.

 

In this case, use an external variable d.c. supply.  This d.c. supply will be adjustable from 0V to the desired voltage (depending on the curve of the tube).

 

Minus of the supply will be connected to GND (J2 pin1 or 2), and the positive pole to the terminal corresponding to the plate (s). To the tube socket but not to the module plate wire.

 

The connection and the sequence of tests are identical to the diodes.

 

Gas-regulated :

 

The test of these tubes is carried out with a resistor in order to limit the current.  The xxx voltage will be seen directly on the display.  Connections between terminal K and plate.

 

Cathodic indicators :

 

The test for luminosity of these tubes can be done simply by connecting its electrodes to the appropriate terminal and by adding the resistance to the plates, according to the schematics of the manual.

 

 

5 Technical features

 

 

Main Board's Dimensions : 146 x 133 x 28 mm ( L x W x H. max )

 

Power Supply : 220V – 230V or 115V / 50-60 Hz or 12V DC via DC to AC converter

 

Power request : 25 to 35 VA max. 

                Approx. 2 amps under 12VDC, via DC to AC converter 

 

Protection fuse : 1 A fast fuse (5 x 20 mm)

 

Measurement mode : pulsed, 8 bits / 12 MHz micro-computer

 

Adc sampling : 10 bits monotonous ( 1024  )

 

Measurement window : 800 µS

 

Interval between measurements : 0.5 second

 

Measurement  accuracy : better than 5% ± 1 digit

 

Grid 1 voltage: 0 to -100 volts minimum

 

Grid 2 voltage :0 to 350 volts minimum

 

Plate voltage :0 to 450 volts minimum

 

Maximal mesurable plate current : 340 mA

 

Grid 2 supply max. current: 60 mA

 

Grid 1 display resolution: 0.1 V ± 1 digit

 

Grid 2 display resolution: 1 V ± 1 digit

 

Plate display resolution: 1 V ± 1 digit

 

Plate current display resolution: 0.1 mA ± 1 digit until 34 mA

                                  1 mA ± 1 digit for I > 34 mA

 

Internal short-circuit protection.

 

Optional AC-DC regulated supply for tubes heating :

 

Output current: 3.5 A maximum

 

Output voltage tolerance : better than 5 % ( regulated )