Telefunken G-73R, is this real or fake?

First about the ECC82 tube. In the eternal search for the best, the rarest, the most exclusive, any ECC82 from Telefunken, were not considered at all. Reason with NOS, is the general belief when something is well available, it can not be good. In addition to that, there still was (and still is) a good supply of NOS ECC82. Even a premium NOS type like 6189WA (double life time version) costs only half the price of a Russian made tube with a vintage USA brand printed on it. Not to speak even of the 5814, which is a real pearl with double life, low grid leakage, higher shock resistance, and a few things more. People refuse to read manufacturer data sheets, as a matter of principle, and for that reason do not know what is written in there. Things must be written on several social media, and from that point on, it is considered true. On this stream of information, or better say lack of information, Telefunken ECC82 was floating, at a low price. ECC82 TFK with diamond bottom was available on Ebay, in sealed boxes, like every week some pieces, or even in five-packs. If offered so regularly, a tube for that reason can not be special, is the general conception. I do not exactly keep list of prices, but let's say in 2010 or 2015 you could easily pick them up on Ebay in mint condition for 20...25 Euro.

Then something happened. Around 2018, a run came on the rare TFK ECC802S, which differs optically from TFK ECC82, so the fakers a could not easily re brand ECC82 as ECC802S. Suddenly ECC802S went for 150 Euro, beginning around 2018. While I write this text in 2025, we see them go now for 500 Euro easily. This may seem a crazy price jump, but it is a raise of only 20% per year, which is normal for the most wanted NOS tubes. You can calculate what 20% over 5 years will do, it is 1.2^5=2.48. So at 20%, what costs 100 Euro in 2025, will cost 248 Euro in 2030. Given this rate,TFK ECC802S will cost 1240 Euro in 2030. In this race for crazy prices, the normal TFK ECC82 was dragged along. They go for 150...200 Euro now.

So the search for Telefunken ECC82 has started. They will get rare, and sound better and better, when prices go higher and higher. In this light we have to see the Telefunken G-73R also.

Telefunken G-73R

What is this tube? I will say it frankly: I am not sure! All I have is information fragments from the internet. When searching the internet via the Google by date, you will see that G-73R suddenly pops up around 2015. These have hand written numbers on it.

I am absolutely not interested in information on social media, because none of this seems to have a source. It is just repeated from the one to the other. For instance some say this tube was made for Agilent, which is pure BS, because Agilent was founded decades after Telefunken closed tubes production. The BS continues with the meaning of the coating. It is probably for better screening. Well perhaps yes. And perhaps not. Where does this information come from? Without facts, this goes into the drawer of unconfirmed stuff.

I was send this picture by email, which is the most genuine I have seen so far. I worked at Hewlett Packard myself, in sales, and I remember selling semi conductor diodes like 5082-2811. These were internal part numbers of a very old numbering system, which was replaced in the 1970's by the later 'H' part number system, like the first LED lamps of HP had for instance the part number HLMP-1000. Optocouplers were called HCPL-xxxx, etc.

What we can say, this tube here, if it is not fake, was from before 1970. And no, it was not made for Agilent. On this box, it writes this is an aged 12AU7.

Call for information: Perhaps someone has an manual of the HP equipment, using this tube? This would PROVE this tube existed indeed. All I see here, is a sticker, which I can produce myself with photoshop as many as I need. Please let me know if you have additional information which has hard facts. I will be glad to add it here, or make corrections to the text now written here, if needed. I try to stay with the facts in this article. Please do not write me about texts which you found in social media by anonymous writers, who do not give a source reference.

G-73R. The easiest to fake tube

Right now, I am not sure if G-73R ever existed at all, or if it was a well done fake. If it was made indeed, one thing is sure: This is the easiest to fake tube ever existing. Any used TFK ECC82 can be used for it, since the tube was 'aged' anyway. The black paint can be done by anyone, it hides whatever is inside. Just the original boxes, as you can see pictured here, they are always gone. With NOS, boxes are sometimes gone, with 20% or so of the tubes. But with G-73R... they are always, always gone. Very strange.

There is something else elementary wrong with 'Labormuster' Stickers I see. Yes these stickers existed, that is true. But it can not be so for G-73R. Let's put the puzzle pieces together for this.

The German word Labormuster means: experimental prototype. And yes, when I search some internet pictures for this, I find tubes like that. Uninteresting tubes, even from the P-Series. This brings me back to Hewlett Packard, my ex-employer. At the beginning of the story, ist that Hewlett Packard box. The only reasonable reliable picture I know. So the Hewlett Packard designation is 5082-0406, and the Telefunken designation for the same is G-73R. So far so good. Now just imagine the situation at HP. They sold this tube in their measurement equipment. The make not just something. They make calibrated equipment for engineering, or for the army, for medical equipment, and even for space applications. Do you really think they use "experimental prototypes" for this? Of course not! That is out of the question. I have a copy here, of what is called the 'environmental manual' by HP. It describes in detail how products are qualified. Before a 5080-Part Number is assigned, products must pass painfully precise procedures. HP was famous for that. 100% sure, HP would never use experimental prototypes. Imagine something goes wrong with a satellite, or someone dies from a medical mistake. Someone opens the equipment, and out come.... experimental prototypes. I worked 17 years at HP myself, and I can tell you: No, they would never do that. It means these stickers on G-73R are fake by definition.

From the same seller from Vietnam, I see such stickers with clear visible traces of digital pixels on it. I am not surprised. I see more evidence of faking with this seller. Such as CCa tubes, labeled CCA., and printed with new, thick paint, instead of printed with this original white ink which is water solvable, and wipes off easily. His auctions have several faked products. Not that I care much about this faker, it is just that I saw faked stickers of G-73R on his website.

Finally, we have asked an ex-Telefunken tubes sales person, who is now retired. He does not remember anything about G-73R. Not remember it, is something else than saying we never made it, but in any case this is what he said.

Conclusion: Any G-73R, I am very very careful. By the HP box, IF this is not a faked box, then they must have existed. But this box is all we have, and the "proof" is a sticker only. That is not much. A sticker can easily be faked with Photoshop. We just would need to see a few more of those boxes. That would be helpful. And finally, if they existed indeed, they have been hidden with ultimate perfection since 50 years. And then now suddenly since 2018, bang! They pop up everywhere, at all kind of web sites, sometimes even in quantities.