Historical HAM Hell-mode station of PA 0 AOB


Most photo's and video films were taken and processed by my wife (XYL) Karin


Down this webpage you find the YouTube links

Please consider first the photos and according text


Yesterday 15 January, Luca Fusari suggested that it might make sense making an overview photo of my station. I agree that it indeed does so.



On the left-hand side you see the Telefunken T200FK39a transmitter. The lower section is the power supply, in the centre my receivers and on the far right we have the AS 60 transmitter, its power supply is also the lower section. Please notice for details the hyperlinks below



Shown is my personal historical HAM station call-sign PA 0 AOB

Most of the shown equipment is now about 70 years old; it nevertheless works still fine and fulfils what may be expected from recent, non digital, technology; however, certainly it is a bit bulkier. Especially the T200FK39a transmitter is for its age extremely frequency stable. It ran, recently measured after a short warming up period during a QSO of about one hour 10 Hz; for a VFO controlled TX a rather good figure. (please notice the graph shown in the T200FK39a link below)

The Hell transmission mode is intriguing me since about 1976, and I am active in this field since.     It once started with purchasing, or was it swopping, of a Feldhellschreiber from Germany. I discussed this subject with Hans Richter DL 7 SK living in Berlin.     He told me, that it is simply possible to operate it in combination with an amateur (HAM) rig; as the Hell machine is provided with a special CW - mode connection. For it one only needs to use a special connector, which, when inserted, automatically disconnects the regular tone system.    

This I desperately would like to operate!

However, Hell was a transmission mode not allowed in the Netherlands. Although, it was was an official transmission system since the International Cairo Conference of 1938! I discussed the matter first with Dick Rollema PA 0 SE. His advice was, to contact Hans Evers PA 0 CX, who then lived in Germany and he also possessed the German call-sign DJ 0 SA.  Hell from its origin was a German transmission mode, once widely used, and was particularly permitted in Germany, likely also in other German speaking countries.

Our first step was getting the German amateur licence papers in which Hell was described. Then I contacted Cor Moerman PA 0 VYL, once a civil servant of the Dutch "Radio Controle Dienst" (RCD) which was the Office for these sorts of matters.

Cor told me, off the records, that no-one was particularly watching these kinds of amateur transmissions, as long one keeps a low profile.    The second move was applying for a Dutch special amateur permission. Cor's point was, that he should apply for it first, as a member of that organisation (RCD) they still could reject the matter without any kind of motivation to civilians. They could, however, not doing this against a member of the same Bureau, without a proper (valid) explanation!   

They tended, luckily for us, to approach it positively; the only bottleneck was, can they monitor such transmissions?    Cor had already traced in the basements of their monitoring station NERA, that they actually possessed a Hell receiver; albeit, it hadn't been used for more than 15 years! No problems, they could theoretically monitor our experimental transmissions. The Germans allowed, without restriction the Feldhell mode (122.5 Baud), and the Dutch Office (formerly known as PTT) decided that we could starting up the experiments. Cor received the positive decision and the next day a group of Dutch HAMs applied also for a special license. Its duration was first limited for, maybe a year or longer. It finally matured, and maybe owing to Klaas Robers' (PA 0 KLS) involvement some years later, it became an integral part of our amateur license.

In the meantime, Dick PA 0 SE wrote articles about the Hell machine also in an American periodical; and Hell mode since attracted interest of many computer fans. The Apple, first computer got programs for it and later IZ 8 BLY wrote a Windows program, which is still rather popular. Hell stations can be worked on many SW amateur bands, especially on 20 metres. In Autumn there is also a Hell contest.

Once, about 1980/81, PA 0 SSB got from me a Hellschreiber on loan, which he used for Moon-Bounce experiments successfully. I somewhere must still have the tape cassette.

On the web there are several websites especially dedicated to Hell mode. An early one was from Murray of New Zealand, I don't know whether it is still 'on the air'. Since some years Frank Doerenberg's Hellschreiber website is comprehensive and is worth to be looked at.  Although, he lives in the South of France, every Sunday possible he links-in via Web-SDR; formerly University Twente, but since they moved to another space, they never were operational fully since. Nowadays the Web-SDR of TU-E (Eindhoven) is often used. 

However, since about late 1976 I am engaged in a Hell-HAM network, which operates every Sunday afternoon. During summer conditions we start at 17.00 CET and during winter time on 16.30. QRG about 3775 - 3790 +/- QRM. Every Sunday, of course, when being at home I am QRV. In its beginning I started on 40 metres (late G5XB Stanly Cook was one of them), but this is a very crowded band and a few years later we moved to 80 m. During vacation time we may be out off the country and it is then quiet Sunday afternoon.

Since 1978 we hold once a year a Hell-meeting. It started with 7 attendees including partners (XYL). At its height we gathered with 27 members which number decreased a bit owing to the age and physical health of some of our fellow members. Especially the old ones which passed the age of 80. Nowadays, those attending are not always active in Hell mode, though, in some respect or another, they have some links to Hell mode operations. 


  Just today 17 January Frank Doerenberg very kindly sent me a copy of that famous Hell meeting photo taken in my QTH of 1980, where I still live

From left to the right: Late Helmut Liebich DL1OY, myself PA0AOB, PA0CSC Cas Caspers, PA0CX/DJ0SA Hans Evers, PA0KLS Klaas Robers, PA0VYL Cor Moerman, PA0SE Dick Rollema, F5VQ now Ni6q Robert or Brian Tompson, late DL1GP Hans Horn

I must revise my thought, Koos PA0KDF is not among this photo; hence, he did not yet joined the Hell group. Though, he certainly did soon thereafter!

My main comment, what were we all young looking 32 years ago!


Last, but not least I hope, the Hell-meeting of 2012:


I forgot all the names, just in front Frank Doerenberg F/N4SPP and next to him Marc Simons. Bastiaan PA3FFZ is the one in the yellow shirt, with whom I have had this day a Hell QSO (13 Jan.). Not all XYLs were among this photo (photo taken with self-exposure by Frank Doerenberg)

Those attending today and also in 1980 were: Myself PA0AOB and PA3BCB Gerard Wolthuis, who just jumped-in in 1980 as to say goodbye,  because he and his XYL had another appointment somewhere in Amsterdam.

I saw a comment today that it is sad that the group has decreased so much, but comparing both photos is not giving that impression. What is true, is the fact that 27 members attended in 2009, when the group met for the first time in our Museum new premises.



In the 1970s the German Bundes Bahn exposed their Hell GL machines, which could, with some modifications, also being used as a 'Feldhell machine'. In the late 1970s the Bundeswehr exposed their Hell 80 machines, which are still around, but does not provide the exact Feldhell system parameters.

However, most active Hell mode stations are using computer programs. Maybe the easiest way of operating Hell mode. They transmit Hell signals in the SSB mode. The only delicate thing is, that RIT control should be used, as to get rid of the LF-tone-offset.

For me personally, operating the original Hellschreiber machine is having a special flavour. Hearing its sound, and, operating it in conjunction with original receivers and transmitters, is 'the intriguing thing'. Doing so now for more than 36 years.


Viewing my HAM station from a different perspective

On the far left-hand side we just see the T200FK39 transmitter, which is extensively described on our website. My current receiver, since many years is not the Köln E52 which its attached SSB adapter, though a KWE-a (Kurzwellenempfänger Anton). A superb receiver, maybe the best CW receiver of its days. Please notice my paper on:

“The significance of German electronic engineering in the 1930s”


The T200FK39a is for its time of conception 1938/1939 a very exceptional apparatus:  


T200FK39a tuned at 3575.9 kHz (my current QSO frequency)

 It is not easy to take photos of this optical frequency scale projected onto a frosted glass-window. The microfilm frequency-scale is actually deposited onto a glass disc, which latter is mounted in the far rear of the VFO exciter module. Its light-rays passing mirrors and even an optical prism. We cannot reproduce the optimal light condition, as the original projection lamp is failing. For it I substituted a small (halogen) lamp being operated at a lower voltage (maybe even a bit out off focus), as to prevent damaging the microfilm content deposited onto the glass disk. The lower mechanical scale is understood to be used when, for what ever reason, the optical system is out of order.

Please bear in mind, that the T200FK39a was meant as to be fit into long-distance U-boats; we have to think of those sent to Penang or even Japan! Our version is having a motor tuning, which keeps the VFO tuning and all other transmitter stages in such a controlled tuning, that when switching over to another wave range (and particular frequency) the central transmitter tuning is about where it only has to be tine-tuned. Submarines lived longer when being submerged! However, they sailed on the sea-surface when being out off the range of Allied air-patrols. Please regard its manual:  T200FK39 transmitter. Quick tuning and transmission was a live saving feature. It was, however, a complicated, and thus expensive option (please notice the mechanics drawing, but don't look at it when you do not sleep well!), which most sets did not have later on; maybe kept where it was indispensable! Stripped T200FK39 versions got a xxx39b, c, d .. extension.


On top of the AS60, my second favoured transmitter, we see the antenna switching and the symmetrical antenna tuner, which tunes the matching of my Zepp-like fed antenna. It constitute for 80 metres a ½ λ length (40 metres long) and for the 40 metre band a full wave aerial. Both well in the spectrum of Zepp like antenna feeding. The open feeders are also visible. For controlling that antenna current exists, an additional small bulb is connected like a Z-Match. It is not the value of the antenna current, though, that current flows what is counting

Please, notice the glowing neon bulb inside the tuner, which responds onto the current electrical field. Operating currently the T200FK39, which provides maximally 200 Watt output power.  

Sometimes, after some years, I switch over to the AS60 transmitter v.v. 


The AS60 transmitter was designed about 1943 and is also a superb transmitter. It was adopted by the Swiss Army about 1944 and got from them type number: M1K

Please notice also our especially to this transmitter dedicated webpage: AS 60  as well as the German wartime manual AS 60 (Ln21210)

The AS60 is of a very special design, very different from what Telefunken about these days produced and designed. Once late Rudolf Ritter (CH) told me, that in contrast to normal practice, this transmitter was initiated by the Telefunken 'Sales Branch'. Viewing its construction, particularly in respect to the way it has been designed this could very well be true! Its VFO layout is outstanding!  In one respect, it used a typical Telefunken feature, being the 'microfilm' frequency scale reading:


According this scale my TX was tuned then at: 3577.8 kHz

It is easily possible to tune-in within a hundred Hz accurately. Give me the type of another VFO controlled TX, for military mobile and/or stationary operations of the 1940s, that provides such an accuracy? Its Tc is according the manual 5 ppm/K.

It has to be said, though, that it takes some time before this value comes into effect; as the VFO responds onto HF as well. And, only after HF is coming into being, the Tc control is becoming active and is finding its equilibrium. A process that takes some time (think of minutes), though, thereafter it is rather stable, maybe not as is the T200FK39a!


This photo session is made on 13 January 2013; in Holland it is mid winter. The QSO starts at 16.30 CET and it is outside already quite dark. However, I regard this having a special atmosphere, which effect is increasing the special experience. That is why I use a bit dim illumination

For this occasion my headphone being moved a bit upwards, as exceptionally, the loudspeaker (Lspr Gerät b) is being operated as well, which is giving a better sound effect when a video film is to be made for YouTube (see down this webpage). Rare, but on the same time also a thrilling experience.


 The current QSO today is with Bastiaan PA 3 FFZ. Koos PA 0 KDF sent me earlier this afternoon an e-mail that owing to family obligation he could not make it to day


I am operating the Hellschreiber keyboard. During this operation I interrupt the running of the paper tape, which I regard paper wasting otherwise. Would I have done so since the early days I would have had kilometres of 15 mm paper tapes. The current tape used is kind fully provided by Antoon PA 0 AST, who found a factory willing to manufacture the Hell paper rolls for a reasonable price

This particular Hellschreiber machine once came from my late friend DL 1 OY Helmut Liebich, who sadly died in July/August 2009; he was a very good old friend of mine. He became ill first and could no longer handle his Hell machine; which he most generously gave to me. His sun took over his call-sign, which may be still heard on amateur bands.

Really, Helmut Liebich DL 1 OY was a most kind person, he was the best one encountered in my life!


The text printed onto the paper tape was received a week ago and was transmitted by Koos PA 0 KDF. He joined our Hell group since, say 1980, as he appeared on a group photo made in my QTH that year (see text above, this is apparently not true). Klaas Robers PA 0 KLS keeping an apple in his hand symbolising that he uses an Apple Computer. Of course, an early type!

The Heart symbol is expressing '88' meaning kisses to ..., a common HAM expression, mainly for those being personal friends. He uses a software Hell-system, which option was integrated into his Hell-mode-program designed by his programmer friend Peter (PA 3 BEK). He just told me that actually Peter adapted a pixel matrix of 14 x 14 dots, which he Koos PA 0 KDF) himself matched (adapted)  so that he can use it in conjunction with the ASCII table as well.  


YouTube films taken during this Feldhellschreiber QSO


Bastiaan PA 3 FFZ is using a FT 7 tranceiver output 10 W. Operating his Laptop



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