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ID = 14411
Great Britain (UK)
Brand: MO Valve Co. Ltd.; GB
Developer: MO Valve Co. Ltd.; GB 
Tube type:  Triode, vacuum   Universal 
  Ca. 1925 up to 1945 rare.
Identical to L63 = VT154_GPO = VR67 = 10E/11448 = 6J5G
Similar Tubes
Normally replaceable-slightly different:
First year Aug.1938 Wireless World (The), London (WW, 79) Show report

Base Octal (Int.Octal, IO) K8A, USA 1935 (Codex=U)
Was used by Radio/TV-reception etc.
Filament Vf 6.3 Volts / If 0.3 Ampere / Indirect / Specified voltage AND current AC/DC

Pa<2.5W, Va<250.

Dimensions (WHD)
incl. pins / tip
34 x 84 x mm / 1.34 x 3.31 x inch
Tube prices 2 Tube prices (visible for members only)
Information source Taschenbuch zum Röhren-Codex 1948/49   
Babani, International Radio Tube Encyclopaedia   Pages 116-117

s_470_g.gif L63: W.Sprick: Austausch-Röhren-Lexikon 1947
Günther Stabe † 19.8.20

Just Qvigstad
L63: my collection
Giuseppe Antonio Tusini

More ...
Usage in Models 1= 1937? ; 1= 1938?? ; 1= 1943?? ; 1= 1943? ; 2= 1945?? ; 1= 1947 ; 2= 1948 ; 5= 1949 ; 1= 1950?? ; 3= 1950 ; 3= 1951 ; 2= 1952 ; 1= 1953? ; 1= 1956?

Quantity of Models at with this tube (valve, valves, valvola, valvole, válvula, lampe):25

Collection of



Forum contributions about this tube
Threads: 1 | Posts: 9
Hits: 3083     Replies: 8
L63 (L63) USA?
Roy Johnson

Dear Collectors

I see that we have two entries for the L63.   L63 designated as a Common tube USA and a L63_MOV.

All the pictures on the "USA" L63 are actually of MOV valves.

Was the L63 manufactured by anyone other than M.O. Valve/GEC?   I have no evidence!

Kind regards to all,


Ernst Erb

Dear Roy

Thank you very much for your remarks regarding the two entries.
I have now changed the maker on the L63 and intended to delete the L63_MOV.

In his early time our collector friend Peter has done what one asked because his knowledge was not yet established. That is no problem if we can correct.

I could not yet delete the L63_MOV because somebody has a "private collecor card" on that one. I now asked him to delete the card and put it on the L63 (where he has one too) and then I will be able to delete that one - except somebody comes up with really a "different type of L63" which then could be a variant of the L63 or even an "underline-tube" like in fact L63_MOV is - but surely on the wrong type - since MOV is THE maker.

Roy Johnson

Dear Ernst,

Thank you very much for your advice.

I did not want to take any action by deleting and moving without seeking confirmation, even when one is fairly sure!

As with the LV90, there is so much still waiting to be discovered.

Kind regards,


Mark Hippenstiel

Dear Roy, dear Ernst,

I have one "Osram (BVA)" of the ST envelope type and one M.W.T. with the T9 tubular envelope in my posession.

While I concord to count Osram to MOV, I'd like to point out that we have MWT as a seperate maker (look here). Maybe the MOV-only theory should be re-thought?


Ernst Erb
  5 Dear Mark
I'm not familiar enough - without research in my books - to decide if it is a mistake to carry also Marconi (M.W.T.) as valve producer/brand but I think it is so.
We list 14 valves for Marconi:


And the many underline types show that there is something wrong ...

If I'm right it is the same group in different times and company decisions.
I'm sure Roy knows much more and will suggest to us what to do. In any case it is essential to know the Osram-story for knowing. I have written about it but not the time to reread it. It is about the same like in Germany where the tubes are stamped Telefunken but built by Osram during many years. The two Osram did not anymore belong together after the founder has sold them - that I can still remember.
Roy Johnson

Dear Ernst, Mark,

The majority of the manufacturers that we list as having made a valve are probably wrong! As Ernst remarks it is not only MOV or UK - it is business.


<1918  Marconi Wireless Telegraph valves were made by Edison Swan. These were badged Marconi. 

1918  Marconi Wireless Telegraph combined with General Electric (The UK one not the USA) to form Marconi-Osram Valves.  GE had made valves but MWT had not.

1920 Marconi-Osram renamed M.O Valve Co.

I am fairly sure that MWT never manufactured valves only early radios and later electronics.

Post 1960 or so we have GEC Electronic Tube Company as the Management Co for English Electric Valve Company and the M-O Valve Company.

SO  What we list as manufacturer depends largely on date and this is very difficult.  I tend to list as manufacturer the earliest that I know from the literature. ( I have changed some from Mazda to Ediswan on that basis). 

BUT - when the same type/named valve was made for a large number of years it could be listed under several manufacturers - GE, EE, M-OV with the SAME badge.  I do not think that would help!  (We should add English Electric, however - I shall ask as I have "parked" a few valves under GEC)

All we can do is to try our best and gradually fill in the details.  The dates are the most difficult to obtain as one never knows if one has the FIRST data book.

I shall try and research more but those are my immediate quick thoughts.

Kind regards,





Ernst Erb

Dear Roy
Yes, that sounds very familiar about this group.
We have in fact two fields:
The maker(s)
The "introducer". We can deal later with the deisgner - or now where we are sure.

I see that in any case we list too many makers for GB:
Example: Gecovalve = we list 10 valves and for General Electric UK we list 9. The difference: Gecovalve is just the or a brand of GE UK ... We should only have the choice for one of them and give the other Code-9-status. 

I'm not quite sure if Code-9-status prevents administrators for selecting the company/brand automatically (?).

Unfortunately it is also very easy for "Company-Administrators" to just tic a field to get this name into the valve manufacturers instead only model manufacturers. Valve companies/brands derive of the same list but have this field ticked.

The rule should be that we get only ONE company/brand fort a group. Tubes after WW2 (e.g. GEC Electronic Tube Company) can go into a different scheme.

If several groups have produced the same valve then we should use "Common tube production Great Britain" and if possible use the field for the designer too. In some cases it is even wise to choose "Common tube type worldwide" - but it might even be better for early valves including WW2 and a few years after to introduce "Common tube production Commonwealth". If Roy tells me to do  so I will introduce this. 

I have not the detailled knowledge to put up those rules for GB and we are all glad that Roy can lead us. so my outlines are only a suggestion. Rome was not built in one day - so we have no hurry. I'm very glad that we will gradually get a good picture for early tubes from GB. The aim is to have really a very distinctive and correct database with as much local knowledge as possible.

Roy Johnson

Dear Ernst,

Thank you for that.  I shall need to think through the implications in detail and come up with a plan. Rome is not yet even planned!

MWT is not listed (correctly) as a valve manufacturer. 

I have applied to add 3 more names.  English Electric Valve, Marconi Applied Technology and e2v which is a current manufacturer.  These are the successors to EEV.   Only "Valve" box ticked.   I believe that we should acknowledge the existence of such manufacturers - how we allocate brands and details to the valves needs to be thought in detail.  MOV and EEV were two separate orgnisations on different sites - GEC were managers, so calling all such valves GEC is perhaps not fair!

Perhaps we just call England and Germany (and Switzerland?) EUROPE!

I shall try and find a little time to come up with a plan. It must be simple enough to operate and provide sufficient detail for both archival and practical use. 

Kind regards,


Ernst Erb
  9 Konrad just told me why the valve was there: The "Codex", a very small booklet whith lists over 10'000 valves (and is full of errors) shows two valves L63 with different electrical parameters. This may be wrong. The only error was that "the right one" was called L63_MOV. Now "the American" will have to be the code-9-tube. Konrad will bring it in (again).

Since "Codex" is very often used by beginners and has been reprinted, we have to list all the valves there. What are the reasons why we have to list all - even if they do not exist?
Since a few persons act as valve administrator it is quite possible that a member tells one of them that the valve is missing here - and then we load it up. Then comes another - like me with the L63_USA and deletes it again ... The game can go on for ever ...
We want to be a real virtual "reference book", not only a catalogue.
If something has been printed in a common book or journal then we have to give reference. In our case of the L63_USA (better even L63_USA?) we have to state in colour maroon (even in bigger size) why this particular tube is not existing (or probably not) but where listed - just
everything we know. If we are (prety) sure we change the valve into code-9 - AFTER we have written our comment.

Dear Roy, I'm glad taht you think first of a plan for that. But I would distinguish between the continent and GB - even suggest Commonwealth. We still can use Europe if this is the case, it is there. Our biggest problem is indeed to combine the "reference book" with the "practical side" for the user who does not read about valves - but "only" uses them.

I see that you have already entered the new brands/manufacturers. We will probably not (yet) have to deal with E2v - but it is good to list the company (of 2002) since we want to be a "reference book". Thank you.
End of forum contributions about this tube

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