uknown KTD tube

Does anybody have some idea about tubes on pictures below ?.

It has label KTD and letters DRP

I have two of them, and both have same number2918 on one side of glass.

One has also number 1206 and other 1052 (seems to be serial numbers)

They are triodes - never used.

Glass holder of anode and grid are similar to tubes made around 1914 ???

 possibly SIEMENS A tube  type ??

Thanks

Danko

 

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• picture 1 (36 KB)
• picture2 (33 KB)
• picture3 (25 KB)

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Dear Danko,

 

can you check if the label is TKD? The tubes look like the Tekade T1_TKD.

 

Best regards

Emilio

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Hi Emilio,

 

Thanks for fast answer.

I think this is not TKD, but they are very similar.

I found some data about early german POST tubes, first made by Siemens. Probably many other  manufacturers were involved, also "my" KTD ;)

So, i made some more pictures which may say some more words about it.

I took them with my 150 Mpix overhead camera. It is not realy suited for that, but this way was possible to extract logo and letters which are not to strong and are not extremly visible for other types of cameras.

First picture shows upper side with letters, and on second are visible Grid and Anode.

Best regards

Danko

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• DN_1 (33 KB)

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Dear Danko

Emilio is right, it is a tube made by TKD (Süddeutsche Telefon-Apparate, Kabel- und Drahtwerke) during WW I.

On your tube the early logo of that company is shown with the large first letter T in the center!
Later, they used the different logo TE KA DE to prevent such missinterpretation. 

DRP means: Deutsches Reichs-Patent and the numbers underneath is the S/N.

 

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Dear Wolfgang,

Thank You for info.

After a while, i found the same.

Here, at RMORG i found some data about Te-Ka-De. There is also info about changing of LOGO.

Almost everything is written somewhere, but it's often hard to find (hi)  ;)

So, now i am almost 100 % sure that my tubes are T1 from TKD.

It is some difference in bakelite parts (shown in RMORG picture), but everything other is the same.

Emilio, Wolfgang, thanks for fast answers and guidance. They were helpfull.

Best regards,

Danko

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