Secret Communications 2 most successful open day for the public, hosting this day a total number of 194 visitors!

This photo impression have been made first by Anton Kroes and second Frans Veltman, although, the latter's contribution hasn't arrived yet.

We therefore will start with Anton's material, whilst Frans's photos will be implemented


This webpage has been initiated on 5 December 2016

Current Status 8 December 2016


Today Frans Veltman's photo's being attached as well.

A dilemma arose, how to attached his photo series onto our website?


For it I have decided to add them onto his current webpage; as this allows the visitor to view them all, or select Frans' contribution separately. In our case, jumping to the according page-section.



However, for  those visiting this webpage for the first time, we would like to advice you to start from here downwards.



Tatjana Joëlle van Vark  is constantly attracting attention

Most of the time it is quite difficult having an undisturbed vision on here displays. Only because Jan Rijnders, who took this photo, kept his camera above his head we can see here.


I suppose that Frans Veltman took a series of pictures on Tatjana's demonstrations; so that we will start with Anton's work, who apparently did not take pictures of here.



My wife Karin in discussion with Marc

Hans Gouwlooze looks a bit scared

(photo by courtesy of Anton Kroes)


I guess, Wouter is guiding a group of representatives from the island Terschelling, who are taking care of the so-called 'Tiger-Stelling' complex

(photo by courtesy of Anton Kroes)

Just in front Maurice Hünen



Just an impression of what visitors would like to investigate

(photo by courtesy of Anton Kroes)



David Shelbourne is also following the conversations

(photo by courtesy of Anton Kroes)



Nobody should dare to pass Wouter, without having put his name onto the visitors list!

Why, because we would like to know at the end of this day how many have joined it.

(photo by courtesy of Anton Kroes)



Even the Master clock (HU 20) is attracting attention which is hanging near to the venue entrance

(photo by courtesy of Anton Kroes)



Nachtfee is attracting quite some attention, we therefore would like to focus on this subject particularly again. We are considering somewhere in- or around November 2017

Please keep an eye on our Website for future information.

(photo by courtesy of Anton Kroes)


Jos Disselhorst in conversation; in the background David Shelbourne is still following the conversations

(photo by courtesy of Anton Kroes)


Maurice Hünen, Anton Kroes' good friend, is studying an electrical coding machine, once designed by Reichert in the 1950s

(photo by courtesy of Anton Kroes)



In front a dismantled TypeX machine, as to show how it once had been constructed. Maurice still there

(photo by courtesy of Anton Kroes)



Job Vermeulen in conversation with Jan Rijnders. On the far right-hand side Mr Didier

(photo by courtesy of Anton Kroes)



I would like to know - how many words have been spoken today?

Just in front Marc in discussion. 

(photo by courtesy of Anton Kroes)



I can well recognise faces, but names? Anyhow, just on the right Paul, who is a Foundation Board-member as well as a personal friend of us

(photo by courtesy of Anton Kroes)



They are browsing through an intriguing, just recently published, German book: Achtung Spione, according '60 years of Bundesnachrichtendienst'

By the way: try to get it. For > 800 well done pages its price is rather low. I paid in Holland recently just 60 Euros for both volumes in a cassette!

(photo by courtesy of Anton Kroes)


Demonstrating the G 1,2 kW short-wave transmitter

One should always take care, due to the 3 kV HT voltage!

The three heavy lamps are dissipating the HF energy and acting as a dummy-load.

(photo by courtesy of Anton Kroes)



It has to be said though, that we run only on low power, because this is for our demonstration sufficient; believe me, those attending are enjoying the demonstration rather much

Sometimes people wonder why these lamps are not glowing at equal strength. The only reason is - that the pair of feeding wires constitute additional inductances.

(photo by courtesy of Anton Kroes)



This is where they are so much intrigued by. The red shining of the RS327 anodes is due to loss in the PA stage. For those wanting to know more, let us consider that η of a triode stage, operating in class C, is 50%, for an output of 400 watts we already encounter a dissipation of 400 watts as well

Normally a heavy blower is being engaged, but this device makes a hell of a noise and I have disconnected it; for it is runs only for some minutes and then only during the Morse-key being pressed down.



Also this transmitter section is impressing visitors

Viewing a pair of RS 282 in parallel acting as a (grid) keying stage.

Designed by C. Loernz AG, according the manual drawings about 1935/36; but being purchased by the Swiss Army in 1942.

(both photos by courtesy of Maurice Hünen)



Apparently 'Nachtfee' is attracting peoples imaginations still, and they are showing increasing interest in this magic apparatus

We therefore have decided to dedicate a full open day at this intriguing system.

You are looking at a Rb-controled frequency standard. It had been especially built such that just the two major Nachtfee signals being delivered: 15,000 Hz and 500 Hz; both sine-waves; as to fit into the Nachtfee system directly.  

(photo by courtesy of Anton Kroes)



The Nachtfee ground console with attached controlling sources

(photo by courtesy of Anton Kroes)



Jos Disselhorst in conversation with Jan-Willen Udo

(photo by courtesy of Anton Kroes)



 One cannot say that they are being bored

(photo by courtesy of Anton Kroes)



Paul is apparently explaining something;

we just might notice a glimpse of my neighbour and friend Fred Breur's back

(photo by courtesy of Anton Kroes)



Jan-Willem Udo likely a bit tired

(photo by courtesy of Anton Kroes)



There is some much mutual interest to talk about. Just noticing Berhard's red pullover

(photo by courtesy of Anton Kroes)



Trevor Sandersons in discussion with Mike Diprose and somebody unknown to me 

(photo by courtesy of Anton Kroes)



Maurice Hünnen just viewing into Anton's camera lens Tatjana

(photo by courtesy of Anton Kroes)


Please notice, that the succession of photos this time originate from Anton Kroes' photo-camera sequence. Our only aim is, to pass on an impression of this most remarkable day; no more no less!




On 8 December 2016

 Fans Veltman's photos being attached as well.



Tatjana is wearing special gloves whilst she is building up here magnificent coding machinery; by the way, during her demonstrations she wears these as well 

Please notice, that we, for simplicity, will not mention time and again, in the according caption spaces, that Frans Veltman is the kind photographer!



This photo provides a special focus on what an intriguing book can do with someone



I don't know all those on this photo, but some I do, on the right-hand side Ms. Blom, our (street) neighbour; and on the left-hand side Carsten Haucke, who came all the way down from the vicinity of Leipzig (in a single day trip!)

Quite unexpectedly, is, that the book 'Achtung Spione' is attracting so much attention.



The two volumes and the cassette are good visible

On the other side of the table we notice Jan-Willem Udo, and, of course, Paul. 



This lady would like to know - how and why it all started

By the way - a good question!



Remco den Besten PA 3 FYM, is particularly interested in Nachtfee, because he attended once a special talk on this intriguing subject; but he has not yet had a chance looking at it in detail 



Luckily Jan Rijnders' wife Marianne supported my wife Karin this day. She and her husband arrived as a 'deus ex machina'. Notwithstanding, that when I entered the kitchen Jan was supporting with washing coffee cups too!

They constituted a real relieve!

Can you imagine having to cope with 194 visitors without help?

Of course not, therefore we are so very pleased that they supported to make this a splendid day!



  Again explaining Nachtfee

In the background Peter Eijlander.



Tatjana explaining her exceptional techniques

For this occasion, she focussed extra on the backgrounds of foregoing coding techniques.



Tatjana's intriguing demonstrations are always attracting attention



A good view on the Enigma's, but it also shows an aspect that: we would like to explain technology in a broader sense. We therefore make, when possible,  visible what is inside a magic box, like is shown on the far left-hand side

The device in front is a type: Schlüssel M4, also known as the Submarine type (introduced after 2 February 1942).

Attached with it is a most rare Schreibmax; the printing device instead of the lamp-field. Normally handling Enigma apparatus demanded two men to operate it. One typing-in the message (plain or coded) and the second man reading-off what is shown at the lamp-field.

Whilst, Schreibmax allows operation by a single operator, as the text is being delivered by the Schreibmax- tape-printer.



This is what it all is about; discussions and explications



Also without my explanations is Nachtfee triggering someone's imagination

From left to right:  Peter Eijlander, Jan-Willem Udo and Peter Denters.




Didier (France), Massimo (Italy), I don't know who the person on the far right-hand side is, maybe also coming from France


Please notice, that for security reasons, the displayed Enigma machines will not be left within our Museum premises outside exhibition hours! 


Please proceed with

Gerard Vos' contribution

Status 24 December 2016


By Arthur O. Bauer