Tubes Articles

FAKES TUBESHall of shame - Fake tubes

LASER FAKED - Telefunken Diamonds found.

The ultimate proof of authentity, the Telefunken diamond <> bottom, is no longer with us. This opens a whole new field for the fakers, because on sites like Ebay, the judgement for what is real or not, is very low. Buyers look only at good feedback of others, but themself they give only good feedback based on quick emotions. They do not understand, products, obsolete since 50 years, can never be on the shelf in quantities of 100's , from several sellers. They all show proudly ultra rare tubes in boxes of 100, on their website.

Naturally the most faked tubes are those where they can easily get raw metarial of. Like fake RFT ECC81 as Siemens ECC801S. That has changed, now the diamond <> has become laser printable, with a real glass melt process. So it is not a coincidence, the offerings of NOS <> tubes have exploded. A box with 100 pcs RFT ECC82 can now be converted in NOS Telefunken, with <> diamond bottem.

The Full Story


Portrait of some interesting tubes. Some broken apart. Some pictured alive. TELEFUNKEN ECC803S

 

 

Portraits


Telefunken ECC803S <>

TELEFUNKEN ECC803S

The Holy Grail of small signal tubes

 

The lost recipe of ECC803S


Game Over for EI tubes

EI Tubes factory closure

This is about the famous EI tube factory. Unfortunately most of the equipment was scrapped recently. This was a shameful destruction of an intact tube factory.

Read more about it here.



Tube Tester Freeware

Simple help page for Dynamic parameters

You have a good tube tester, but it can not measure dynamic parameters, like Gm, Gain, or Rp? Well most of the time you can, but you need to make aifferential measurement.

Instead of having to explain this just use this little Excel Worksheet. You can select the tube you want, or enter the data by hand in the right table.

Then you need to do Measurement 1 + 2 and you have the Transconductance. (Gm). If you also do Measurement 3 + 4 you get in addition the Gain the the Plate impedance.

Even so, you can use this program to check the performance of a tester, that is able to test Gm or even Rp and Gain. And no, this sheet makes no errors. Any differences are caused by the tester itself, since there are analog circuits also in digital testers, and even digital, you have the problem of low resolution if cheap A/D converters are chosen, such as in the AT1000.

DOWNLOAD HERE.



Dear Alesa, can you build my "fun" tubes?
Lemming Effect

A true story about AVVT, and the first single plate 2A3 re-issue ever since 1950. About the first mesh tubes we made, out first 274B, and many more tubes, our followers uses as examples.

Read full article here.



A mysterious "constant current user"

Or why voltage specified heaters should be voltage driven.
By Jac van de Walle

Computer Aided Testing

 

More information here


 

About Tin Whiskers

This is what happens when you use 100% pure tin.

More information here



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