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Information - Help 
ID = 19354
Brand: Philips; Eindhoven (tubes international!); Miniwatt
Tube type:  Triode, vacuum   Universal 
Identical to A410 = PR37_Condor = PR37_Pope
Similar Tubes
Normally replaceable-slightly different:
  5.XX. ; A9 ; LP2_Philips ; R36 ; V1520
Other base:
First Source (s)
1924 : Saga of the Vacuumtube, Tyne p.421

Base Europe 4-Pin (A, 4A, B4, since 1914) (Codex=Eo)
Was used by Radio/TV-reception etc.
Filament Vf 4 Volts / If 0.06 Ampere / Direct / Battery = /
Description S= 0,5 mA/V; 10-fache Verstärkung; Ri= 20kOhm; wurde auch mit UX4-Sockel geliefert 
Text in other languages (may differ)

Alan Scott Douglas † 16.11.15

A410: Telefunken Werkstattbuch
Wolfgang Bauer

A410: own collection
Peter den Boer

Usage in Models 4= 1924 ; 1= 1925? ; 19= 1925 ; 3= 1926? ; 12= 1926 ; 2= 1927?? ; 5= 1927? ; 10= 1927 ; 4= 1928?? ; 17= 1928? ; 6= 1928 ; 2= 1929?? ; 1= 1929? ; 2= 1929 ; 1= 1930? ; 4= 1930 ; 2= 1931??

Quantity of Models at with this tube (valve, valves, valvola, valvole, válvula, lampe):95

Forum contributions about this tube
Threads: 2 | Posts: 6
Hits: 1579     Replies: 1
A410 (A410)
Georges Van Campenhout

Dear all,


in the Olens Radiomuseum (Belgium) I found a set, equipped with 4 Philips tubes A410. At the back of the tubes, there are two strange markings: the first says RECLAME, and the second, in thinner lettering: INUTILISABLE. This french word means 'cannot be used'.

As I understand it are these lamps meant for pubilcity. I measured the heater, and it is seems to be open circuit!

Has anyone an explanation for it?

Christian ADAM

Dear Georges,

You may be right. As "réclame" means "for advertisement", may be these tubes came out damaged from the factory but have been distributed to the dealers for the show room for example.

It's interesting...


Hits: 1843     Replies: 3
A410_Philips (A410_Philips)
Mark Hippenstiel

Hallo zusammen,

kann mir jemand erklären, warum Valvo eine A410 mit Werten, die von denen der Philips-A410 abweichen, hergestellt hat? Oder sind unsere technischen Daten bei der Valvo inkorrekt und es handelt sich doch um die selbe Röhre?

Ich will da keine Baustelle aufmachen, aber es würde mich schon interessieren, ob es auch noch ähnliche Fälle gegeben hat.

Danke, und viele Grüße
Mark Hippenstiel


Roy Johnson

Dear Mark,

I do not know for certain in this case, but one quite probable reason is that they were named independently. There was no agreement between manufacturers in 1925.

The numbers chosen were the obvious ones 410 =  4V 0.10A  (406 0.060A). 

Then there was the pressure to reduce battery consumption so a valve would be announced as 0.06A  then a little later a small ca  (approximately) can be seen in the leaflets! 

Also even when a type was "copied" production possibly led to a slightly different product!

There are many cases of tubes being named the same but with completely different function - not only a difference in characteristics.   For example DE1 and DE2 appear as both triodes and rectifiers.

Perhaps someone knows for certain the A410 story, but my guess is simultaneous naming.

Kind regards,



Wolfgang Bauer

Mr. Hupse wrote:

Hello Mark,
I cannot answer directly to your forum contribution because there is no reply button available for me...
The Valvo A410 is a 100 mA triode, designed for serial supply in DC radio sets. It is almost equal to the Philips B415. And not equal to the Philips A410 or Philips A415, as these tubes only consume 65 mA.
Best regards,
John Hupse
Mark Hippenstiel

Dear John, and dear Roy,

thanks for the further insight. I recollected that  the merger (or take-over) between Philips and C.H.F. Müller had already taken place when those two types were released.

But this would only take place ca. 2 years later (1927) - and a Philips prospectus of 1927 calls the A410 an "old" tube already, now (application-wise) superseeded by A442 and A453, but still on stock or production.

I would have guessed that even back then companies would have looked over the fence (of their home market), especially in the case of Philips which employed a very expansive strategy already from the beginning.

But Roy's probably right, since both types were released in 1925, only a year (or less) after the founding of Valvo.


End of forum contributions about this tube

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