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DET9

Information - Help 
ID = 17716
       
Country:
Great Britain (UK)
Brand: Marconi-Osram - (Valves/Tubes); GB
Tube type:  Transmitting Triode, air cooled   Power/Output 
Identical to DET9 = CV2899

Base Europe 4-Pin B4 (Eu A, E, 4A) 1914
Was used by Transmittertube (Radio)
Filament Vf 2 Volts / If 0.3 Ampere / Direct / Battery =
Description

Typ; Va=250, Ia=15mA; Ra=3k; gm=2.3 This tube was a low power transmitting type.

 
Information source Taschenbuch zum Röhren-Codex 1948/49   
- - Manufacturers Literature   

b4_base_pins~~379.png DET9: Fin Stewart
Fin Stewart


Just Qvigstad

Collection of

 
ro_marconi_det9_front.jpg

DET9
 

Forum contributions about this tube
DET9
Threads: 1 | Posts: 14
Hits: 4094     Replies: 13
Question about this Marconi.
Francisc VISKY
26.Sep.07
  1 The serial number it can not be seen. I think this is a very old Marconi tube. But what type it is? There is a black spot in the place where the serial number should be.

Attachments

Reiner Scholz
27.Sep.07
  2 Hello Francisc, I assume, this is a L610 type. My similar looking tube is showing  "MADE & PATENDED IN ENGLAND" in an oval circle  and inside of this "L610" with an adittional 74 and 2.
Brans tube compendium calls A 615 as corresponding.
The black spot at your tube is hiding the MWTC (Marconi Wireless Telegraph Co) logo.
Reiner Scholz
27.Sep.07
  3 Hier noch 2 Fotos

Attachments

Francisc VISKY
27.Sep.07
  4 Hi, Reiner,

Thank you for helping me. I not see in your picture the socket, is it the same with the Marconi's. On my reversed picture it can be seen a 4 figure. But I am not positive...
Reiner Scholz
27.Sep.07
  5 Hi Francisc,
yes I left out a photo showing the socket because it´s exactly the same one.
I did not yet find any more information on this triode.
Roy Johnson
27.Sep.07
  6

Francisc,

It could well be a L610, but please compare with the specimen in the National Valve Museum, HERE.  The size, base and structure should help.

If the vacuum  and filament are intact you may care to check that it is indeed a 6V tube.

Regards,

Roy

P.S.   Reiner, please load a picture as there is not one for the L610 - thank you. 

Reiner Scholz
27.Sep.07
  7 Thanks Roy for that information.
Yes, I am happy to load the pictutre but want to assure myself,  the listed TUNGSRAM L610 tube is identical to the MARCONI type.
Francisc VISKY
27.Sep.07
  8 Roy,
As usual your comments are very well done, thaks for making clear the doubts around this nice tube from the early of radio communication.

Best regards,
Francisc
Roy Johnson
27.Sep.07
  9

Reiner, Francisc

Thank you!  I am not convinced about the Tungsram L610 and can find no reference to it.  The cited Taschenbuch zum Röhren-Codex 1948/49  may be in error. 

However, I shall leave it in existence and ask for it to be verified.  If the Tungsram and Marconi have identical characteristics we can amalgamate.

In the meantime, for security,  I have added the L610_Marconi for your pictures.    

Regards,

Roy

Francisc VISKY
28.Sep.07
  10 Dear Roy,
I just wanted to upload the picture when I took a look again  to my Marconi and I have seen some yellow marks. After a soft cleaning the following inscription came up:

....ED & PATENTED IN ENGLAND

The first letters should be 'manufactur' I guess, then under the '&' sign there is '51' and under the letter 'N' (from England) there is a '1'. It is written  roundly.

End now the surprise, at lest for me, the type is

DET 9
         
I tested several times using a magnifier (x6) and breathing many time on the glass!

Also in my oldest Radio Valve Data (1958, MK Budapest) there are six type of L610 only one has a 'D' at the end but what is strange is that there is one with 4 v heater voltage the rest with 6 v. The manufacturers are:
Geco        (L610)
Lissen      (L610, 4v heater)
Tungsram (L610)
Valvo       (L610)
Osram     (L610, L610D)

On the RM there is an empty page for DET 9....
Roy Johnson
28.Sep.07
  11

Thank you for the dilligence Francisc!  

I have added data to the DET9 which also met the CV specification CV2899.    This type was available from the manufacturers as late as 1963 although from existing stocks and of a later pattern.

The most common circular writing said "MADE & PATENTED IN ENGLAND".  The 51 is a batch coding.

As before mentioned, I find that putting the tube in the refridgerator for a period before trying to read weak markings as the slight moisture lasts longer and enables focussing and even photography.

Now that we are certain of your tube, please load the pictures.

Regards,

Roy

Ernst Erb
28.Sep.07
  12 I moved the thread to the tube DET9. Interesting story how we nearly went wrong ;-)
Francisc VISKY
28.Sep.07
  13 Loading the pictures I did a mistake: a loaded the wrong source. The source is good for L610 but not for The DET9. How to proceed ?

P.S.
Roy, thanks for the idea with the refrigerator.
Roy Johnson
28.Sep.07
  14

It seems that your three pictures of the DET9 tube are correctly placed on the DET9 page ready to be shown.  What is the problem, please?

Roy

 
DET9
End of forum contributions about this tube

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