EL33

 Attention : dans Sélection Rapid Tubes des éditions ETSF, le tube EL33 est donné comme l'équivalent d'un 6V6, ce qui est une grave erreur. Le 6V6 est une tétrode à faisceaux dirigés avec une pente de de 4 tandis que le EL33 est une penthode pure avec une pente de 9.

MD

  Hello, Radio Friends members,

It will be that la válvula EL33 (Mullard) it is equivalent to the valve KT61, (Marconi).

Retired data the book in Spanish of the author R. J. Darkness. 1.ª edition November 1956.

Best Regards

Júlio Branco

Hello Júlio Branco,
 

The EL33 (or 6M6) it is NOT equivalent to the KT61. This data book is not serious !

A Philips or Mullard data book would never make such recommendations.

The EL33 needs a cathode resistor of 150 ohms at least, while the KT61 needs a cathode resistor of only 90 ohms.

Without changing the cathode resistor the EL33 and the KT61 may never be used to replacing each other.

As a makeshift one can use a KT61 to replace an EL33, but the performance will decrease.

An EL33 should never be used as direct replacement for the KT61. Due to the wrong cathode resistor the EL33 will be severely overloaded and will give only low performance.

Best Regards, Jacob

Amigos miembros,

Será que la válvula EL33 (Mullard) es equivalente a la válvula KT61, (Marconi).

Datos retirados el libro en español del autor R. J. Darkness.

1.ª edición Noviembre 1956

Com os meus cordiales cumprimentos

Júlio Branco

 Hello Júlio Branco,

El EL33 (o 6M6) no es equivalente al KT61. ¡Este libro de datos no es serio!

El libro de datos de Philips o de Mullard nunca haría tales recomendaciones.

El EL33 necesita un resistor del cátodo de 150 ohmios por lo menos, mientras que el KT61 necesita un resistor del cátodo de solamente 90 ohmios.

Sin el cambio del resistor del cátodo el EL33 y el KT61 se pueden nunca utilizar a substituirse. Pues de expediente puede utilizar un KT61 para substituir un EL33, pero el funcionamiento disminuirá.

Un EL33 se debe nunca utilizar como reemplazo directo para el KT61. Debido al resistor incorrecto del cátodo el EL33 será sobrecargado y dará seriamente solamente de resultado inferior.

Recuerdos,

Jacob

Dear Members

This information can be very useful goes my dear friends of the radio.

The tube EL33 directly can be substituted by the tube 6M6.

Best regards

Júlio Branco

Dear Julio,

I have just seen that you also posted to the EL33, so I copy my comments made to the 6V6 below  as a caution.

"The 6V6 and EL33 are NOT equivalent!  A hasty note of warning!

They have the same base, connections and heater volts but differ considerably.  THe heater current of the EL33 is 0.9A compared with 0.45A for the 6V6.

More seriously the biasing requirements are different and could cause dangerous excess anode currents.  Replacing an EL33 with a 6V6 without changing grid bias would not be a good idea!

The power limitation on the EL33 is 9W whereas the 6V6 is 12W; the output impedance is different.

Whilst it may "work" to exchange these tubes it should not be done without circuit changes.

Regards to all,   Roy"

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Also kindly act please on Mr Erb's request to remove "directly" in your posting so that there is no possible confusion!  We must be careful not to leave information that could prove dangerous to equipment or to people!  Thank you.

Kind regards,   Roy

Dear Members,

I ask all excuse goes my previous information. I was induced in mistake by the fact of my manual of tubes to incorrect be. I won't usually check the technical dates of to manual when this it informs us that equivalence direct exists, in fact, to present it date, I have been following the instructions of the manuals and I have always been having success in my work. Then the reason goes the which I don't have the habit of checking the manuals I or in correct the. Inclusively to removes you doubt if he had or in the tube averaged EL33 changed goes the 6V6, the in the manual he felt this information, I made the experience given that had available the tube 6V6, the radio worked, what concluded that EL33 was damaged. I removed to 6V6, I acquired an EL33, being like this with the concluded work and without noticing the mistake that was to commit. I already analysed the tube 6V6 and it is 100 percent, it was not damaged.

A thank you very much goes all of the information that gave me on the tubes EL33, 6M6 and 6V6, once again it is confirmed that this forum is very important, and where us been always to learn.

Best Regards

Júlio Branco

Dear Julio
Nevermind. But it is essential that we also keep record of the faults in publications since we want to achieve a "reference work" here. We are far from that but on a way to it.

I kindly ask you to take this sheet you have shown to us, cross the V so taht it is still well visible and write over it M. Then scan it again and load it up with a text explaining in which book you found it and on which page.

Please do this in your first post by editing - on both entries (tubes). Then everybody has learnt something and a newcomer will not do the same but recognise that that book is wrong. You will rarely ind a book where everything is correct. It is the big gain for us that we can always improve our data to the best - but we will have to take notice of reasons and references, proofs etc.

Attachments

• Radio_tubes_page (36 KB)
• EL33_6V6 (56 KB)

I'm sorry, Hernst

Lately I have been walking with a lot of work, reason for the which I didn't put in the post that suggested to do.

Here it is going the alert and so that all of the members of Rmorg, and not only, for everyone that visits this grandiose site to be possessors of this book they make the respective correction.

forumdata/users/3656/Tube_EL33_6V6.png

forumdata/users/3656/Radio_tubes_book_page1.png

Best Regards

Júlio Branco