Foundation C.D.V. & T. thoughts


Page initiated on 18 July 2013

Status: 7 August 2013

Update: 2


The relevance of quasi ‘stand-alone’ artefacts lacking a context


Having previously considered about the precautions to be taken as to maintain the aims of our Foundation for the long term - putting up a vision with an open end is not very helpful - there need to be a strategy; at least one that can be discussed.


It is not only a legal matter that is counting though, also what is the significance of old techniques? Nowadays, progress is going extremely fast and the life-cycle of a product from its planned conception is maximally five- maybe a few years more. Who knows what was common practice two decades ago? Considering, techniques of more than seventy years ago is like talking about ancient history. But, these techniques where used in the 1950s and maybe in the 1960s still.    


Finding an artefact might causing a lot of queries, like:

For what was it once used? (branch)

How did it work? (principles)

What was its context?

Was it once state of the art? (accuracy)


What often occurs, is, that a device comes without any context. Like a meter, but that it was part of a test arrangement is impossible to know, unless one once might have seen it in another configuration.


Please notice, that most photos, without further notice, have been kindly taken by Phil Judkins; these were taken in the barn where the devices were found recently. Its purpose was: informing me what the items are about, that was what counted; these were never intended for this (web-page) purpose!





An ac current meter

Considering its scale linearity, my guess is that it is being equipped with diodes. A thermocouple would have provided a non-linear scale reading, whether a hot-wires is behaving like this scale is not known to me.

Viewing the meter connections, these clearly show that the meter was meant for HF measurements, and it is thus likely that a hot-wire technique is involved; I believe that a thermocouple is causing a far more exposed non linearity scale.



Viewing it from a different angle

What was its purpose and what does imply both text information?

This item was amongst a big bunch of devices which comes very kindly from late Graham Wimbold recently. We can, nevertheless, partly answer some of the open queries. For it we have to take additional photos in September. Nevertheless, the engraved text is a warning that one should not touch the electrical contacts when measurements being taken. Although, I wasn’t aware of, but it closes a gap of my previous understanding.


A small and bit fuzzy photo originally part of a  current display, showing the Bakelite tray viewed from  beside

This may also clear the point why the previous meter is curved asymmetrically, as it has to fit within the tray with other meter devices.

A set of meters being kept together in a Bakelite open tray in our exhibition. My previous understanding was as to store these items, which still maybe one of its purposes. But, it also most likely was as to insulate the meter(s) from its surrounding, because the meters might be carrying rather high voltages levels, be it ac, dc or HF signals or even both combined. This proves, that when an artefact is being considered, that a curator must have an understanding of what kind of measurements and techniques might have been once dealt with. Is this an exceptional device? Yes and no. It does, nevertheless, only make sense when the way it once have been constructed is understood appropriately.    

This tiny photo is derived from an existing display overview showing the Bakelite tray and a glimpse of two meters inside it. The relevance of this meter gear is that it becomes possible, for example, to measure the input of a transmitter and monitoring instantly its HF output behaviour. For it insulation against ground is an important stipulation.



An example of combined realistic measurements

Please notice the necessity of strict insulation against each other! I will not say, however, that this set of meters was operated just in conjunction with the pulse modulator IG62a of the Würzburg system.  

For it we have to make in September more detailed photos.



Another intriguing device is our ‘Airborne Command’ transmitter and likely receiver (transponder?). Already for decades part of our collection.


That it apparently has a transmitter function can be derived from the electrical circuit. It even may incorporate a tone-selective stage;  whether the selected tone originating from the 'not available' receiver module is triggering the transmitter is not understood.  



A photo of the Airborne Command  transmitter (transponder)

Viewing: just at the tank-circuit of the transmitter output stage. The label L10 (facing towards us) is just the point where the receiver signal enters (inductively) the selective-tone section (Rö 11 acting likely as a diode detector).


The tuneable coil L15 in combination with C 69 and the green other ones (not good visible) is selecting likely different tone frequencies

The red-brown resistors clearly show that this module was assembled in a Philips factory.

Please consider for more information the Aircraft Command transponder page


It is rather likely that it was meant for fitting into a rocket or into a sort of to be guided bomb. It operates somewhere in the 300 MHz band. Looking at the kind of components used, it was assembled by the Philips Company; however, definitely not designed by them! This is curious, as Eindhoven was liberated in September 1944, it should thus have been manufactured before this date. An option might be, that it was still somewhere in the Philips stores in Eindhoven when Eindhoven was liberated. I have for it to ask the previous owner Jan Wolthuis for additional information.

All those familiar with German modular construction technologies know that it never could have been designed by the Philips Company. Likely, they might have manufactured it on behalf of a GAF branch. Most small electrical components originate from Philips. However not all, some from Hescho as well. The valve sockets are labelled as was common German practice.



But, also the curious mechanical/electric timer device  fog M32    

Also part of our collection.


The curious timer device M 32

Whether the device is set at: 50 minutes or 50 hours we don't know.


The only clear conclusion from the producer code ‘fog’ is



The German Black-Forest area is well known for its watch and clock makers. Viewing the photos there can be no doubt that it is a high quality device.

Again, its exact purpose is unknown (though, still in concert with the production company designation ‘Kontrollapparate’). That it has a timer function is evident. We do not have the intension to operate it, thus we have to wait until someone answers this query.


Isn't it beautiful?

Last May I visited Günter Hütter, and saw the same type of device among his collection. When we opened it, I was quite surprised, because it lacked half the gearing mechanism! Ours has two ‘un-rests’, Günter’s sample possesses only a single one. Was this due to a later simplification as to save expensive (strategic) raw materials?

Considering the expensive way it was constructed, my guess is that it was once meant for the GAF; which had been equipped with the best gear available.




Continuing, with Graham Wimbold's gear


Within the same bunch of Graham’s remains, was a typical German GAF blue/grey box. Seeing the fuzzy 'R IV' did instantly ring a bell.

Rudolf Staritz told me a few months ago that the only known Siemens R IV receiver was sadly donated to an entity in Karlsruhe. This receiver type was once employed by the German Abwehr in their Hamburg station at Wohldorf.


Viewing the R IV power supply label

I have to apologise for the fact that this photo is rather fuzzy.

Phil took it when he gathered the German gear from late Graham Wimbold's barn, which is most generously donated to our Foundation.

The label, nevertheless, points what it actually is.



The loudspeaker window, although, I cannot see one. Maybe its opening is just at the opposite side of this box. My guess, this side actually is meant for air flow cooling

Whether a loudspeaker would have been operated generally is rather doubtful, because the Germans used in the very most cases headphones.


I phoned Staritz and told him that we should get the power supply unit to a R IV receiver. This receiver is rather exceptional, as it is based on the HRO technique, however, in contrast to the genuine HRO and its German KST copy, the coil box was to be accessed from the top lid. The next photos, also originating from Staritz’s collection, shows this, albeit, vaguely. One of the coil boxes is clearly visible. Whether it belonged to another (second) band or that this was the way it was mounted is not yet known (viewing this photo again, my impression is that the coil-box should be mounted on top of the RX box). A later review makes it plausible that the coil box should be put in the open space left of the visible coil box. Why should be there otherwise a hole, the tuning section is then just underneath the plugged-in coil box contacts.

A Google search provided that someone is selling a small document on the curious R IV. Interestingly, Staritz told me that the loudspeaker should be incorporated inside this power supply. The set he knew of - owned by a recently died collector - was without this unit. This would mean: - that Staritz must have noticed it during his wartime engagements with the Abwehr Service. Very remarkable indeed!


The receiver R IV shown on the right-hand side, the power supply on the left with on top an old telephone type. Whether the device in between the power supply and the R IV RX is housing a loudspeaker is not known to me

The sign on the wall indicates that this was receiving place number 10 (Platz Nr. 10)



The main room on the 1st floor (in the US they call it second floor)

Very interesting, is, that on the far left-hand side we see a Hammerlund Super Pro receiver. Next to it, I guess, a German HRO copy known as KST. The Hammerlund gear might have been obtained via Portugal. The previous photo was taken in the same room, from the camera position on the right-hand side.


The 'Ausland Abwehr Funkstelle Wohldorf'

The previously shown receiver room is on the first floor just behind the open windows

For full information please consider, my CHiDE paper on Abwehr wireless



Another device among Graham’s artefacts, is a curious meter.


This meter apparently is a voltmeter combined with an ohm meter meant for cable testing




The meter can be also hold (fixed) by the operators belt

Operational instructions are clearly provided

I must admit, that I have never seen such a device before.



Sometimes we come across interesting devices, which once was part of an system outfit; but the most wanted remained and the not direct useful items is being neglected. This fact makes side techniques more valuable than the set of which it once was part of. For example, the tank receiver or transmitter are widely around, as > 100,000 have been produced. Its mounting frame in contrast is extremely rare. Sets can be found, but the cabling and plugs can be rather wanted items.



Another intriguing device is a ‘stereo optic’ (Brückenraumglas) device which was used for aerial photographs. In recent days one may get the impression that only Britain possessed such a secret or magic stereoscopic technology. This photo proves, however, that the Germans must have used it too. Whether their conclusions had equal impact I cannot judge. 


The GAF stereoscopic photo viewer


Detail photo of the content of the transport case (Fl 38025)

Apparently, watching the screw-slits, the lid must have been removed before.

Typical German way of stock-part numbering - the stereoscopic glass + mounting carries GAF stock number Fl 38460 + Fl 38461



What to think of the next box?




On its top lid is painted the abbreviation: Str.Tfl. A.

Being rather acquainted to German abbreviations, this most likely stood for – Strecken Tafel type A. (range table A) Please consider the next photo

As the devices have not arrived in Holland yet, we have to wait for a thorough investigation.



Certainly a kind of calculation table (Streckenzugtafel A)


What the real purpose is, is not yet understood

It might point into the direction of a kind of distance measurements in the horizontal- as well as vertical plane?


I have asked, of course, my friend Werner Thote from Radeberg. In first instance he could not answer my query, but he passed on the question on to an old friend; This is what he replied:

Lieber Werner,
da müssen wir wohl einmal einen Vermessungsfachmann fragen. Karten stellen nur die
senkrechte Projektion des Geländeprofis dar, nicht aber die wahre Länge zwischen
Standort und anvisiertem Meßpunkt. Mit Hilfe dieser Tafeln kann als Funktion der
Neigung bezogen auf die Horizontale die wahre Länge ermittelt werden. Üblicherweise
wird dazu am Theodoliten diese Neigung abgelesen und  mittels Winkelfunktion die
gewünschte Länge ermittelt. Die Tafeln ermöglichen das ohne Berechnung durch
Nun hatte die Artillerie früher viel  mit der Vermessung zu tun, so daß eine
militärische Verwendung nicht ausgeschlossen werden kann. Inzwischen erledigen das
auch schon Rechner.


Another, very strange box contains a ‘Hypsometer'.


The only thing that can be derived from a label – is that it was used for daily calibration of a barometric device. The British mains plug points into the direction that this apparatus was once operated in Britain. 


The Hypso meter kept in its box


Whether Graham operated it our another entity I don't know. 


This label tells us - that it concerned a Navy Hypsometer

For continuous correction of a 'Aneroid-Barometer'. Calibration to be done on daily bases. The Hypsometer should be kept near to the DUT


A detail photo of the Hypsometer

'M' tells us that it was once German Navy property.

Serial number 373/Obs

For obvious reason, we have covered photographically the so-called 'Pleite Geier' or Hoheitsadler.

The suffix 'Obs.' points into the direction of weather observation. Weather forecast was a very important source of information for the Germans. As operational actions, but also artillery-data was depending upon these kinds of data.

These weather data messages were transmitted in a particular Morse code and always started with the 'WW' symbols.

Please consider also my book: Funkpeilung als alliierte Waffe gegen deutsche U-Boote 1939 - 1945



What to think of a brown Al. box?


 Containing a single axis gyroscope and two repeater potentiometers; of which one is coupled with a gyro axis

Flugrichtungs means: Flight direction

From a recent photo from Horst Beck, we know that the centre hole between the two connectors was fitted onto a 14 pin List-Stecker (connector)


The second one may be linked onto one of the three aeroplane axis. The other one repeats the actual gyro vector of the spinning gyro-axis



At the rear of this platform is a camm-gear-wheel.

The wiring is strange, as it might indicate that not to long (1960s?) ago it was used in an experimental set up. 


This photo of the same device, looks a bit friendlier. The camm-gear-wheel is also better visible

I have called the European expert Horst Beck. He told me that it apparently was called: Richtgerät 44 and that an optical system was part of this system. The text ‘Kursschaltkasten’ might point that the gyro had to maintain correct targeting of the fighter aircraft (Kursaufschaltung?) it might have been interacted with the auto pilot (gyro system)



A trouvaille is a small diode.



It clearly was designed for minimal capacitance between the anode and the filament

My guess, it was manufactured by Gundelach.




Another curious device is a box with a range of plugs.


Apparently an acoustical range measurement combiner apparatus

Horst Beck told me that it belonged to an acoustical range measuring system.


Considering what the next photo suggests, internally is printer device, which prints on a quite wide paper tape.


Not being noticed instantly - this printing device is an integral part of the acoustical range central (combiner?) unit

Which can be seen at the bottom of this photo, the photo is been taken from beside.

How it works, and where it once have been operated cannot yet be answered.


To be continued in due course.