quality control is/was very inconsistent. the ECC83 had microphony problem; the nickle plate EI ECC83 is most famouse for being or going microphonic. nearly all unsold nickel plate EI ECC83 are microphonic or very badly mismatched triodes or both. perhaps all are defects. i do not know.
The story is actually a bit longer and significantly different. EI never bought any Telefunken tooling.
EI signed a contract with Philips on January 16th, 1959. The license for 11 types of noval electron tubes and one octal tube (PL36) was taken over. Original Philips machines for production of electron tubes and instruments for tube testing were purchased. EI personnel were trained by Philips engineers in Nis. Many workers and engineers from Nis spent a couple of months in training at various Philips factories in Holland. Production on the new line began the same year.
Telefunken approached EI in the fall of 1960 with a request to manufacture the ECC82/ECC83 anodes. Telefunken never had a production of the same capacity as Philips. All Philips tube machines were well ahead of their time in terms of speed and other features. Especially the machines for metal parts were many times faster, as well as the automatic grid winders.
ECC82/ECC83 anode tool was constructed in the middle of 1961, and the production started in the beginning of 1962. Telefunken smooth 17mm (actually 16.5mm) anodes were made on a Philips Anode Press, with EI Nis tooling, at very high speed with exceptional quality.
So what was the tooling origin at Ei between 1948 and 1959 ?
What is meaning : "were made on a Philips anode press, with Ei Nis tooling" ?
What about the ECC88 ?
If some parts were comming from Holland and Philips tooling (>1958), I imagine Ei Ecc88 from 1959 to circa 80 (Grunf input) should be as good (quality control apart/ dispersion of the half triodes ratio) than all the others manufactures with the same tooling on the same period ?
That's relative, we know some cheated an time period where the tube was on spec is not the same for all
What is meaning : "were made on a Philips anode press, with Ei Nis tooling" ?
What about the ECC88 ?
If some parts were comming from Holland and Philips tooling (>1958), I imagine Ei Ecc88 from 1959 to circa 80 (Grunf input) should be as good (quality control apart/ dispersion of the half triodes ratio) than all the others manufactures with the same tooling on the same period ?
That's relative, we know some cheated an time period where the tube was on spec is not the same for all
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One more time ... The story is actually quite long and significantly, significantly different.
Behind the widespread misconception, that the first vacuum tubes in EI Nis were made on Philips equipment, there is an almost unbelievable post-war story, especially for today's time.
Back in 1947, the Yugoslav government sent a delegation to visit Siemens. The delegation that traveled to Berlin consisted of Dr. Lazar Perovic and two engineers. Their task was to buy x-ray tubes, since no x-ray machine worked in the war-ravaged country. Instead of x-ray tubes, the delegation returned with a contract to take over a complete line for the production of electron tubes, which was taken as war reparations.
Nis was chosen almost by chance. The then mayor, Mr. Slavoljub Petrovic Djera, promised free apartments for German engineers, technicians, craftsmen and their families. And that decided it.
The first German experts arrived in May 1948, and 71 apartments were provided for them. At the beginning of June, the rest of the engineers and technicians and most of the equipment arrived from West and East Germany.
Although the war wounds were fresh, the Germans were cordially and warmly welcomed and placed in nice apartments with their families. And that surprised them incredibly. German workers were very satisfied with the city of Nis. Even today, Nis is a city very well known in Serbia for its hospitality, for its numerous cafes and restaurants, and for its good food. The living conditions were great, they had nice accommodation and salaries three times higher than local employees. They were very satisfied.
Since you mentioned Russian tools, it should be noted that at the end of 1947 and at the beginning of 1948, cooperation with Russian experts was also planned. However, that's when the fight between Tito and Stalin begins and the change in Yugoslavia's course towards West. All this culminated in Bucharest, at the Cominform session on June 28, 1948, Informbiro begins. But the construction of the factory could not be stopped.
Since Nis is very close to the Bulgarian border and the factory of vacuum tubes is of strategic importance, an initiative was launched, and later there were many pressures to move the factory to Sibenik, Croatia. In the end, the German experts did not want to go anywhere from Nis, and without them, in the absence of Russian experts, there would not even be a factory.
The first tube that was made in RR Zavod Nis was AZ1 in 1951.
I don't know how familiar you are with the technology of the production of electron tubes, which is quite complex, so I will simplify my answer a bit.
The anode tools (the tooling) were made in Nis, the mica tools as well. Both tools were done by Nis workers based on the Philips AZ1. And all the following tools were made in Nis by Serbian engineers and workers.
Stems were made on Gustav Bruckner machines, only tubulation was made on a Gladitz machine. The bulbs were made at the Serbian Glass Factory in Paracin, Serbia.
The heaters are wound on an automatic Gustav Bruckner machine. Also, all welding was done on a Gustav Bruckner welding machine. As well as sealing process.
Exhaust process was done on an automatic Schmid and Kleinberg machine with Elektra vacuum pumps.
Forming of tubes were done on rack made by RR Nis workers.
The grids for ECH21 and EBL21 were made on Telefunken's automatic machine and on 5 manual grid winders.
In the beginning, 150 AZ1 were made per day, and in 1958 half a million valves were made, of which 220,000 were AZ1. EI also made: ECH21, EBL21, 6K7G, EZ12, EZ21, UCH21, UBL21, …
That's the beginning of RR Zavodi Nis (Elektronska Industrija Nis, EI Nis) in short. The next era is cooperation with Philips, and growing into a real giant that produced more than a million tubes per month.
Dragan
tubes.rs
Behind the widespread misconception, that the first vacuum tubes in EI Nis were made on Philips equipment, there is an almost unbelievable post-war story, especially for today's time.
Back in 1947, the Yugoslav government sent a delegation to visit Siemens. The delegation that traveled to Berlin consisted of Dr. Lazar Perovic and two engineers. Their task was to buy x-ray tubes, since no x-ray machine worked in the war-ravaged country. Instead of x-ray tubes, the delegation returned with a contract to take over a complete line for the production of electron tubes, which was taken as war reparations.
Nis was chosen almost by chance. The then mayor, Mr. Slavoljub Petrovic Djera, promised free apartments for German engineers, technicians, craftsmen and their families. And that decided it.
The first German experts arrived in May 1948, and 71 apartments were provided for them. At the beginning of June, the rest of the engineers and technicians and most of the equipment arrived from West and East Germany.
Although the war wounds were fresh, the Germans were cordially and warmly welcomed and placed in nice apartments with their families. And that surprised them incredibly. German workers were very satisfied with the city of Nis. Even today, Nis is a city very well known in Serbia for its hospitality, for its numerous cafes and restaurants, and for its good food. The living conditions were great, they had nice accommodation and salaries three times higher than local employees. They were very satisfied.
Since you mentioned Russian tools, it should be noted that at the end of 1947 and at the beginning of 1948, cooperation with Russian experts was also planned. However, that's when the fight between Tito and Stalin begins and the change in Yugoslavia's course towards West. All this culminated in Bucharest, at the Cominform session on June 28, 1948, Informbiro begins. But the construction of the factory could not be stopped.
Since Nis is very close to the Bulgarian border and the factory of vacuum tubes is of strategic importance, an initiative was launched, and later there were many pressures to move the factory to Sibenik, Croatia. In the end, the German experts did not want to go anywhere from Nis, and without them, in the absence of Russian experts, there would not even be a factory.
The first tube that was made in RR Zavod Nis was AZ1 in 1951.
I don't know how familiar you are with the technology of the production of electron tubes, which is quite complex, so I will simplify my answer a bit.
The anode tools (the tooling) were made in Nis, the mica tools as well. Both tools were done by Nis workers based on the Philips AZ1. And all the following tools were made in Nis by Serbian engineers and workers.
Stems were made on Gustav Bruckner machines, only tubulation was made on a Gladitz machine. The bulbs were made at the Serbian Glass Factory in Paracin, Serbia.
The heaters are wound on an automatic Gustav Bruckner machine. Also, all welding was done on a Gustav Bruckner welding machine. As well as sealing process.
Exhaust process was done on an automatic Schmid and Kleinberg machine with Elektra vacuum pumps.
Forming of tubes were done on rack made by RR Nis workers.
The grids for ECH21 and EBL21 were made on Telefunken's automatic machine and on 5 manual grid winders.
In the beginning, 150 AZ1 were made per day, and in 1958 half a million valves were made, of which 220,000 were AZ1. EI also made: ECH21, EBL21, 6K7G, EZ12, EZ21, UCH21, UBL21, …
That's the beginning of RR Zavodi Nis (Elektronska Industrija Nis, EI Nis) in short. The next era is cooperation with Philips, and growing into a real giant that produced more than a million tubes per month.
Dragan
tubes.rs
The meaning is as follows: The machine for making anodes is from Philips, and all the tools were made by Nis experts.
I will try to simplify.
This is that machine: Multi slide (4 slide) Philips anode press.
The best way to understand what tooling is and the real meaning of my words is to google for 4 slide metal stamping and forming process
I could write a lot about it, but I'm not sure you would understand it correctly.
More than ten years ago I wrote a short article about Telefunken ECC83 (Smooth Anodes).
I will surely write about ECC88 / 6DJ8 and E88CC / 6922 soon, but I still don't know when.
Thanks for your very informative and somewhat thrilling stories, Dragan 👍 !
Anyway, I'm scratching my head why the Serbian workers and employees decided for the Philips AZ1 as the antetype, although they had been trained by Siemens engineers (from Munich?), as I do understand your writings.
Best regards!
Appaired 5% max ?
This would be great news to me and safe a lot of work
Would you know what exactly got appaired to 5% max
and tell where you did find this 5% claim?
Thank You
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that was the average number gap between the half triode out of the plants because of carefull assembly, selected and special made parts.
Don't remember if on Philips datasheet.
Don't remember if on Philips datasheet.
Natural born storyteller 😉. Lucky for you, English is not my native language!
@radiostar
Thanks for that history lesson. I relived my childhood. I migrated from Serbia (Zemun) to Australia (Sydney) many decades ago 🙂
EI Nis tubes were very well regarded.... their 6DJ8, EL34 & KT90, in particular.
Thanks for that history lesson. I relived my childhood. I migrated from Serbia (Zemun) to Australia (Sydney) many decades ago 🙂
EI Nis tubes were very well regarded.... their 6DJ8, EL34 & KT90, in particular.
The Dutch were very smart guys. Way ahead of anyone in the field of tube manufacturing at that time. There were also a couple of brilliant guys in Serbia, so it doesn't surprise me at all why Philips was chosen.
The Germans were from Telefunken, Siemens and Lorenz.
AZ1 was simplified, because they had a problem with Gustav Bruckner stem machine. They were made without central support rods. Also, the first 2500 pieces were made with mica parts from Holland, then a mica tool was made and mica from Prokuplje and Macedonia was used.
Look at those spot welds 😵! They still had to learn something 😉. And they did, of course.
Best regards!
Best regards!
Did Ei stamped ECC88 with 6dj8 marking for the Asia-Pacific and american market ?
I have read when E.I. recieved lately the Philips toolings from others european plants that closed, E.I. then also stamped Philips on some batch for Philips itself (with Philips box as well) as did Polam in Polland.
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Here's the tube I used... as a front end in The HYBRID circuit (https://digilander.libero.it/essentialaudio/hybrid_circuit.htm)
Thanks for the picture. first time I see doublle marking like that. ... interresting !
6DJ8 marking seems syrilic marking so certainly genuine.
Is there a time code ?
6DJ8 marking seems syrilic marking so certainly genuine.
Is there a time code ?
I don't know... can not remember the time code. I made that amp probably some 35 years ago.
The long & skinny Ei KT90 was my favourite from that era. I remember the beautiful sound even to this date.
The long & skinny Ei KT90 was my favourite from that era. I remember the beautiful sound even to this date.
ah, maybe the tube needs to be changed now ?That's a 5 000 hours tube ! Or at least you certainly made zillions of amps since...
6DJ8 - It is not Cyrilic marking - it is Latinic marking, as below ECC88.
On the boxes "Industrija" means Industry, written in latinic.
We used and laerned at school both Cyrilic and Latinic writing.