View Full Version : German Funkmess: request for information

05-20-2007, 04:14 AM
Request for information

As we all know, the "Battle of Britain" did not only see the use of RADAR on the british side for air defense coordination, but the germans also utilized similar technologies. Research has revealed a few holes in the documentation and we would like to ask you - the community - to help us filling these holes.


The use of german ground-based radar is well known for later stages of the war, but unfortunately we have not managed to obtain precise information on the use of this earliest german radar beyond anecdotal reports. So far we have managed to find hints, that the Wehrmacht had placed two FREYA stations at the Channel Coast in order to monitor british shipping in the Channel. Apparently these FREYA stations have not been used for coordination of air assets, though. Our questions here are:

<LI> Is our information on the Wehrmacht's use of FREYA during the "Battle of Britain" correct? Were there really just two FREYA installations on the Channel Coast?
<LI> What was their exact designation and type (model)?
<LI> Where were these installations located?

2.) "Wotan I" and "X-Verfahren"

We have managed to find the following description on the use of "Wotan I" in combat.


In 1933, Dr. Hans Plendl from the DVL mad a suggestion for a VHF-Precision-Navigation System which would allow the dropping of bombs in bad weather without visual contact with the target. In the spring of 1934 he received a contract for the development of this "X-System."
Dr. Plendl was appointed the director of the RL Department of the DVL in Rechlin (later the Group F at the Research Institute of the Air Force at Rechlin). The "X-System" worked on the principal that a guiding beam was directed over the target and served as a course beam. Two other beams on different frequencies intersected the course beam at right angles prior to the target. The beams allowed the pilot to determine his speed over the ground with a special "X-Clock" to determine the correct release time for his bombs.
After extensive testing by the group headed by Dr. W. Kuehnhold, the "Wotan 1" UHFNavigation System working on 66 – 77 MHz was operational in 1937. The antenna was made up of two vertical arrays one which transmitted a continuous a signal and the other an intermittent 120 cycles per minute signal. A series of 14 beams with a width of plus minus 0.05 degrees each with Dot/Dash signals modulated to 2,000 Hz were transmitted. A larger version with 18 beams was also developed. Using 14 beams was necessary obtain a high beam resolution. This made it difficult for the user and also his opponent to determine which one of the beams was the correct one to use. The antenna was later supplemented with two reflectors which made it possible to increase the range. Eight of these systems, also called the
"Multi-Beam Rechlin System," were installed around Germany in 1938. At the end of the year most of them were transferred to the western front. After the capitulation of France, ten of these systems were transferred to the channel coast.


Working in the E-Group at Telefunken (H. Hahnel, Dr. Rucklin) developed the "X-Receiver" (FuG 22) code name "Anna" which operated on a frequency of 66-77 MHz. The receivers were produced by Siemens. The circuit was similar to the EB1 2 receiver, however an amplifier was added to differentiate pulsed signals. The display, AFN 2, was used and connected to two anodes such that one needle showed the localizer beam and the other the transverse beams. The "X-Receiver" was installed in He 111 H aircraft and used in September 1939 against Poland and England in August 1940 to June 1941 from Vannes and from then on from Chartres.


The system was used as follows: The frequency of the UHF-beam (A) was tuned into the first receiver which was tracked by the pilot. See the figure on the next page. The flight engineer
manned the second receiver and it was his job to determine the time that the aircraft crossed the transverse beam signals (B) and (C) which transmitted at different frequencies. Usually these beams were detected 18 and 6 km before the target and used to determine the ground speed of the aircraft. A "X-Clock" (fabricated by Hartmann & Braun, later by Beurle & Sons) was used to calculate the time to the target. Wind drift, altitude, aircraft speed was measured and accounted for. The clock would then show the time for the aircraft to drop its bomb.

So the basics for the utilization of "X-Verfahren" are quite clear, but we hope for more precise information and maybe additional details on the plane-based components of the system. Our questions here are :

<LI> What was the exact technical designation of "Wotan I"?
<LI> Which additional units or devices were necessary to operate "Wotan I"?
<LI> Where were such "Wotan I" stations located during the "Battle of Britain"?

3.) "Wotan II" and "Y-Verfahren"

The details for "Wotan II" and its use are sketchier. All we could find was the following:

German Ultrashort Wave Y Navigational Procedure
The Y procedure, introduced at the end of 1940/beginning of 1941, provides both the indication of direction and distance. In order to achieve this, the sound modulation of the ground transmitter received by the airplane is sent back with a different frequency. The distance calculated from the phase difference is sent out by means of synchronized pulses.

Our questions are:

<LI> Can anyone supply more detailed information on the "Y-Verfahren" and its technical details?
<LI> What was the exact technical designation of "Wotan II"?
<LI> Which additional units or devices were necessary to operate "Wotan II"?
<LI> Where were such "Wotan II" stations located during the "Battle of Britain"?

Thanks in advance.

Foo'bar & csThor

05-20-2007, 07:34 AM
Maybe here ?


05-20-2007, 08:26 AM
That is the source of both quotes http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

05-20-2007, 09:46 AM
Thor and Foobar,

You should try contacting the owner of this site. http://beim-zeugmeister.de/zeugmeister/index.php?id=7&L=1

I know him, he probably has loads of data on this matter, I sadly don't, being a collector of other type of papers. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif If you can't find his email adress there contact me in email using kurfurst@atw.hu , I don't want to post it here. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Also I have some info on this, but it's better be in email. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

05-20-2007, 04:34 PM
Have you already found this page?

The locations for the X and Y-Verfahren (for example WESER and RHEIN mentioned in the article above) can be found on this page:

I read that the first Freya radar station in France was built at Wissant on the Pas de Calais in July 1940 and operated by the 7./Luftgau-Nachrichten-Regiment 1 (according to ww2.dk). Apparently the radar was used (only?) for locating ships in the English Channel as mentioned here:

I suggest you try to get copies of these books if you need more informations:
"Die deutschen Funkmessverfahren bis 1945" by Fritz Trenkle
"Die Geschichte der Luftnachrichtentruppe" by Karl Otto Hoffmann

05-24-2007, 07:13 AM
Here is something for you Guys, hope i can help a little bit...



German language, but interesting: http://www.lostplaces.de/cms/content/view/64/33/

Regards, Rinreiber.

05-27-2007, 12:40 PM
This link is not for France but Norway and contains interesting info on radar & radio, It shows just what the Axis were using circa 1939-1940.

Check out all the links


"X Reciever" I believe was used to bomb Coventry, Bombers flew on the "beam" outbound from France and listened for the second beam usually transmitted from Holland, as the second beam came into range it had pulses on the carrier, as the target area was neared the pulses became more rapid till the single carrier tone was heard on the target area, then bombs away.

Please remeber this is an account I have read a long time ago and may be totally inaccurate from the source and my memory.

05-31-2007, 10:11 AM
Maybe this book could bring fundamental information about Funkmess / Radar:

Gebhard Aders
"Geschichte der deutschen Nachtjagd 1917-1945"
Motorbuch Verlag, Stuttgart, ISBN 3-87943-509-X
First print in 1977, 390pages
With many sketches that show how the different electrical appliances work.

But I don't` know if an english edition exist.
That book is out of print, maybe second- hand ...

http://www.abebooks.de/servlet/SearchResults?tn=Geschic...t&an=Aders&y=13&x=94 (http://www.abebooks.de/servlet/SearchResults?tn=Geschichte+der+deutschen+Nachtjag d&sortby=3&sts=t&an=Aders&y=13&x=94)

06-02-2007, 08:01 AM
"Most Secret War" by R.V. Jones gives some interesting background information on British countermeasures against the German beams and radar.

06-07-2007, 03:33 PM









I think this is closer to what you may be looking for.

06-09-2007, 06:52 AM
WOW! http://forums.ubi.com/images/smilies/11.gif

06-18-2007, 07:27 AM
june 1940:

..... They were, in addition, a valuable way for the Kampfgruppen to learn the art of night navigation but, as a result of their premature use, the radio beams associated with the highly secret Knickebein bombing and navigation aid were quickly detected by the British enabling effective counter-measures to be put in hand.

Knickebein, named after a German folk tale magic crow who could see in the dark, was available to the entire bomber force, its signals being picked up on the 'blind' landing receivers fitted as standard to all German bombers. When used for navigational purposes only one beam was employed, but for radio assisted bombing the system employed two transmitter stations which formed a beam intersection over the prescribed objective, allowing the attack to take place without reference to the ground below.

august 1940:

Over the Bristol area, owing to bad weather, a period relative calm set in on the 19th, and this lasted until the evening of August 22nd. It was then that conditions improved enough to allow KGr 100, the only unit in the Luftwaffe to be equipped with the sophisticated X-Verfahren electronic navigation and bombing aid, to carry out their first precision attack under Luftflotte 3, the target being the Bristol Aeroplane Company at Filton.

X-Verfahren was a complex system employing a main and three cross beams which gave the pilot aural indications 50 km, 20 km and 5 km out from the target. It's chief disadvantage, however, was that it was only able to operate in conjunction with specially-equipped aircraft manned by crews trained in its use.

taken from:


Kongo Otto
07-15-2007, 04:19 PM
Schau hier mal Foo.bar:
Gyges (http://www.gyges.dk/index.htm)

Für Bauten zum Thema Funkmeß
Lostplaces.de (http://www.lostplaces.de/forum/index.php)

07-16-2007, 03:26 AM
Ist das nicht eine geile Seite? Da war ich neulich durch Zufall auch schon drauf. Danke http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

07-21-2007, 03:30 PM

08-07-2007, 03:16 PM
Hi Foo,

are You asking for something detailed as this?


Feel free to contact me

aka ZG15_FALKE http://forums.ubi.com/images/smilies/touche.gif

at sturmovik.de Forum, since I will not follow up this thread.


08-07-2007, 09:49 PM
Yes! The more detailed the better! http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

08-08-2007, 09:36 PM
Yea, as long as i've been here this has been Waldo's thing...the one to get info from. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

08-08-2007, 10:03 PM
the one to get info from
Too kind LBF. But nobody can know everything about anything. I sent Foobar some more info via pm, and he was nice enough to call "interesting and complete information"

If you want something like this to be accurate you can NEVER have enough info. (I know that's the case with my modest research. I would like more info on Radar in Defiants, Ventura's Firefly's - but it is scarce to come by!
W32Blaster stuff is from a Trenkle book, very good information, terrific and I bet very welcome indeed.

08-08-2007, 10:55 PM
http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif :bag:

09-21-2007, 03:08 AM
Found this link on the HP of I./JG27:


And to keep all info in one place, my fotos from Berlin Technikmuseum again:

By tbag_13 (http://profile.imageshack.us/user/tbag_13), shot with Canon DIGITAL IXUS 700 (http://profile.imageshack.us/camerabuy.php?model=Canon+DIGITAL+IXUS+700&make=Canon) at 2007-09-19

By tbag_13 (http://profile.imageshack.us/user/tbag_13), shot with Canon DIGITAL IXUS 700 (http://profile.imageshack.us/camerabuy.php?model=Canon+DIGITAL+IXUS+700&make=Canon) at 2007-09-19

By tbag_13 (http://profile.imageshack.us/user/tbag_13), shot with Canon DIGITAL IXUS 700 (http://profile.imageshack.us/camerabuy.php?model=Canon+DIGITAL+IXUS+700&make=Canon) at 2007-09-19

05-02-2008, 01:23 PM
here some infos for the "Würzburg" Radar:
http://www.xs4all.nl/~aobauer/DecknameWB.pdf (http://www.xs4all.nl/%7Eaobauer/DecknameWB.pdf)

some Pictures:

hope it help you!

05-04-2008, 10:03 AM
Good stuff NSU!

05-15-2008, 07:29 AM
Just found this page about the "Knickebein":


On the main site you can find some of the instruments needed for using this system. If translation of this stuff is needed please contact me.

05-15-2008, 04:20 PM
another german radar guidance system.."Erika"



Erika was a late development in radio guidance, and came too late to have much effect on the German's war effort. They had started with Knickebein, then progressed to X-Gerat and Y-Gerat, all of which were far superior to anything the Allies had at that time. The only problem with this system was the large number of bunkers needed which allowed the planes of the RAF to spot the installations. Erika was a long distance navigation system. The transmitting station sent out two tones and equipment on the bomber gave the position to the air crew to within an accuracy of 400 meters. Unfortunately by the time the system was operational the Germans had little or no air force remaining. At St Pierre Eglise there are six installations each with a radio bunker and two generator bunkers. At the heart of the centre was a fortified control room which supervised the transmitting of the signals. By the time the system became available the German had very few aircraft in the sky. I am told that there is a large tunnel system under the town of St Pierre, but as yet I have found no trace.