Question about this Marconi.

ID: 149786
This article refers to the component: To the tube/semiconductor

Question about this Marconi. 
26.Sep.07 22:06
0

Francisc VISKY (RO)
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Francisc VISKY

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:

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 2
L610 
27.Sep.07 19:16

Reiner Scholz (D)
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Reiner Scholz

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.

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 3
 
27.Sep.07 19:24

Reiner Scholz (D)
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Reiner Scholz

 4
Marconi? 
27.Sep.07 19:32

Francisc VISKY (RO)
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Francisc VISKY

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...

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 5
 
27.Sep.07 20:32

Reiner Scholz (D)
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Reiner Scholz

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.

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 6
L610 
27.Sep.07 20:31

Roy Johnson (GB)
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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. 

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 7
Here we are  
27.Sep.07 20:51

Reiner Scholz (D)
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Reiner Scholz

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.

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 8
L610 
27.Sep.07 22:05

Francisc VISKY (RO)
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Francisc VISKY

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

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 9
L610 
27.Sep.07 22:55

Roy Johnson (GB)
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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

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 10
L610??? 
28.Sep.07 09:26

Francisc VISKY (RO)
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Francisc VISKY

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....

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 11
DET9 
28.Sep.07 10:42

Roy Johnson (GB)
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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

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 12
DET9 
28.Sep.07 15:12

Ernst Erb (CH)
Officer
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Ernst Erb

I moved the thread to the tube DET9. Interesting story how we nearly went wrong ;-)

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 13
DET9 
28.Sep.07 20:48

Francisc VISKY (RO)
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Francisc VISKY

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.

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 14
 
28.Sep.07 21:19

Roy Johnson (GB)
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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

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