Some wartime espionage undertaken at Philips Eindhoven


It is most exceptional that one is coming across this kind of material.

What can we learn from this originally negative, thus black background with white text, "photo copies"?

For this occasion I have converted it into a positive copy. As to notice how the original sheet looks like, please click on the illustration at the top.

We posses a range of these kinds of copies, but it does not make sense reproducing well known information (neglecting the espionage information in its header which are all the same)


What can we learn from this file?

GB3266/43. This number is used on all Telefunken data sheet copies which are available here.

Van Harry voor Karel    Both names likely were codenames. As in wartime usually, the resistance groups were always using fake names. As to prevent that the Germans could match a name to an existing individual. We may assume, that both persons involved had any name, but certainly not Karel nor Harry. The serial number is equal for all of these messages; /43 indicates that it is 1943 information.

Intriguing is, that the valve types LV9 - LV10 - LV11 and LV12 never had reached the production stage. Although, some prototypes are around like the one in our collection LV9. However, Philips had definitely been involved in the development of the so-called: Nasenkolben Größe A1. Nasenkolben indicate that the 'spigot' is realised by means of a so-called guiding glass nose. By the way, also a Telefunken patent DE857538, application date 26 June 1941, finally granted 21 February 1952. I guess, that the spin-off of this wartime work done on behalf of the Germans (they paid for it) might have influenced the development of the post war Rimlock valve series (like EF40, EL41, ECC40 and that like).

Please notice the very interesting wartime article on the development of this project (FTM 1942). Please notice also Telefunken's wartime patent application: DE762245. I strongly believe, though, that the basic philosophy behind it was very clever. The entire project was, however, never fully implemented; as the wartime circumstances made this impossible. Some valve types, nevertheless, reached widespread employment (LV3 - LV13 - LG12 - LG200 ... ).

I guess, that we never will know who was behind Harry and Karel, but that they have exposed their lives by informing the Britons about German wartime projects is doubtless.

'Voor' Ware office is also clear  ('voor' means 'for', 'van' means 'from').

Byl VI is a bit uncertain. It might mean bijlage (attachment to) or that someone BYL in London was involved, I don't know?

The next documents below might indicate that materials had first been conveyed to the Dutch Government in London.


Philips wartime information over the period 1941 - 1943/44 reached also London and, according the accompanied letter, it was handed over by the Dutch Government in London onto the British intelligence.

I strongly doubt that this kind of information can be found anywhere else on the web.


Shown is the first page of a British wartime document

It apparently covers 1941 most of 1944. I guess, that some must have been related to Valvo production figures as well. As Eindhoven had been liberated in September 1944.

Philips Lamps LTD, Eindhoven, (PDF)

File date maybe originating from late 1944 or early 1945


Some aspects of the list on delivered items is of interest

By the way, as so often, the Britons maybe not the Dutch passed on inaccurate information PSH0/B should be: PSU o/B; down EA?50 should, most likely, be EF50 ....


Other interesting figures are about the rare EFF50 and EFF51

I only know about the application of the EFF50, which was used in the front-end stage of the Kreuzeck receiver; the Jagdschloss receiver designed by Siemens & Halske.

The figure of 4000 EFF50s produced is quite easy understandable

My guess: The Germans intended the production of about 80 Jagdschloss systems all together. Then is a figure of about 4 x 80 x 10 spare sets and experimental valves versus the 80 systems to be scheduled quite realistic. When we estimate that 10 times for each system is to be kept in stock. (4 x 80 = 320; 10 complete sets per Jagdschloss system is making 3200; 800 for tests and research is 4000)  Also the production of 1000 DAH50s might be for some valve collectors of interest.




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