Jagdschloß A (Jagdschloss A)

FuG 404

German PPI radar system

Lehrunterlagen

Technical training manual for radar engineers

Ln Schule 8

Lehrschule für Fernmeldetechnik

Detmold

November 1944

2. Auflage (second edition)

Oberkommando der Luftwaffe

Generalnachrichtenführer

Ln.-Inspektion - 6. Abtlg.

All together 317 manuals had been printed

PDF, 4.9 MB

 

There existed two wave ranges, let us call them respectively A and B: 120 - 157 MHz and 157 - 250 MHz. According to a source, serial production started late 1943. Up to April 1945 were: 18 systems of wave region B and 62 of range A*. Thus, a total number of 80 systems were delivered to the German air defence organisation (Luftwaffe). We don't know exactly how many system became finally operational. *Frequency range A overlapped the regular Freya wave-band.

 

Die Jagdschloss-Anlagen stammen in ihrer Weiterentwicklung von der Firma Siemens (S&H).

Jagdschloss A

Dies ist die zur Zeit ausgeführte Anlage.

Jagschloss B (geplant)   Es bestand von Anfang an der Wunsch, das in einer Gerätestellung gewonnene Luftlagebild an eine zentrale Befehlsstelle zu übertragen. Für die Übertragung des Bildes sind bei der A-Ausführung drei Komponenten erforderlich und zwar ..... (partial text of page 5

 

Jagdschloss radar antenna-array, seen from the rear. This typical brick-stone building may have been (sometimes) on top of an 'underground bunker'

 

 

Keywords: Blockschaltbild Jagdschloss B mit Übertragungseinrichtung; Sternschreiber; Prinzip der Synchronisierung bei Jagdschloss B; Blockschaltbild Jagdschloss A mit Übertragungseinrichtung; Übersichtsskizze Anlage Jagdschloss B; Übersichtskizze Anlage Jagdhaus; Kennung (IFF); Duplexbetrieb; Bildübertragung; Allgem. Meßprinzip der Rundsuchanlagen; Stufenschaltbild der Rundsuchanlage Jagdschloss A; Verdrahtung f. Jagdschloß; Antennen-Anlagen; Aufbau der Antenne; Speisung der Antenne (Kabelplan); Einheitsfeld; Breitbanddipol Ortskurve; Änderung der Strahlungscharakteristik; Kabelplan der Antenne für Jagdschloß; Strahlungsdiagramm; Der Breitbandübertrager; Übertrager 70 Ohm auf 70/2 Ohm; Frequenzgerät; Wirkungsweise; Bedienungsanweisung für Z Gerät; Prüfvorschrift für Z Gerät; Prinzipschaltbid Z-Gerät Phasenschieber (delay line); Zusatzgerät zum Z-Gerät Wirkungsweise Kompl. Scahltbild Zusatzgerät Prüfungsvorschrift; Beobachtungsgerät, Wikungsweise; Im OB-Teil; Prinzipschaltbild Beobachtungsgerät; Gerät R, Einsatz RH101, RN105, RJ102; Prinzipschaltbild R-Gerät; Kompl.Schaltbild Hochtastgerät (20 kV zum Sender); Kompl. Schaltbild Steuerteil; Sender mit TS41; Vorläufige Prüfvorschrift für das Gerät Eibsee mit Gittertastung;  Breitband-Simultangerät Rießersee (Riessersee) T/R section; Riessersee 2, Riessersee 3; Prüfvorschrift für Riessersee I, SD6; Der Breitbandempfänger, Technische Angaben, Beschreibung D Zwischenferquenzteiles; EEF50 (EFF 50) at the receiver front-end; EFF50 data sheet; Radar receiver Kreuzeck, Prüfvorschrift für das Gerät Kreuzeck, Bedienungsanweisung; Sternschreiber PPI display unit technical circuit description; Blockschaltbild Sternschreiber; Gleichlaufübertragung, Synchronisierung; Lichtsirene, Photozellenverstärker; Drehstromverstärker; Impulsgerät, Aufgabe, prf 500 Hz, EZ150(double rectifier); Bildwähler, Synchronisierung; Aufbau der Kennungsantenne; HF-Verdahtung des Standes; Antennen-Antrieb; Komplette Röhrenbestückung-Jagdschloß; PPI CRT type LB40 m/3, HR2/100/1,5                

 

Half section of the Jagdschloss antenna array. Its antenna field is horizontally polarized, whereas the vertical radiators in the upper section belong to the IFF system

 

Fine range measuring set-up of Jagdschloss (Ansicht des Gerätestandes Deckel geöffnet). IFF is the receiver for "Identification Friend or Foo" (code-name "Gemse"), RX is the radar receiver "Kreuzeck", with its front-end (see page 83). RD is the fine-range display CRT, the three clocks on its right indicate mechanically the distance(range) marker (regard also report TME 11-219). Not quite clear, but the magnifying lens had been pulled (fixed) upwards

 

 

 

The PPI display unit (Sternschreiber), cover-plate being removed. The CRT had,  presumably, a screen diameter of 40 cm (LB40 m/3)

 

 

"Landbriefträger", shown is the carrier interface which was used to transmit radar (video)signals onto remote Command Stations like to an "air-defence operation centre" (Ansicht der Übertagungsanlage). The data was sent via broad-band cable facilities

 

At the other end of the line was the receiving-end of the radar-data-transmission system, also equipped with a simultaneously operating PPI display (Sternschreiber)

 

Shown is: the broad-band Jagdschloss transmitter on the right. Left of it is placed the (automatic or simultaneous) "transmit-receive" switch (T/R). This probability maybe an older version

 

 

 

RAF offensive on Berlin with approximately 400 aircraft, on 30 January 1944. The circle constitute the 100 km range marker, the gap in top indicates 'geographical north' (Nordmarke)

 

Hans Jucker kindly referred to this contribution:

Dear Arthur,

 

the latest increase of your  website, the  “Lehrunterlage Jagdschloss A”  for the German VHF Surveillance Radarsystem as well  as the Technical Manual 11-219  are both very interesting authentic papers for seriously interested fellows in radar history. 

 

Please let me introduce some remarks according the content of the papers:

 

A former Siemens & Halske representative held a couple of years ago an interesting lecture about the development of the German WWII “Jagdschloss” surveillance radar. He pointed out then, that the basic idea for the plan position representation of radar information (if the slant range and azimuth coordinates of the various targets in the field of view are represented) was borne 1936/37 at the Gema company, Berlin. However, the most restrictive reason for the realization of surveillance radars was the limited performance of the early radar transmitters and receivers.

In opposite to searchlight radars with the typical pencil beam the surveillance radar needs actually a beam that is fanned in the vertical direction, if aircraft are to be observed. So, for a similar power density at the illuminated coverage, the radiated energy must be higher than for the searchlight radar. However the power capability of the Freya transmitters couldn’t be increased without a time consuming new tube program.

Therefore occasionally the development of the “Jagdschloss” Surveillance Radar, Siemens & Halske tried to compensate the insufficient radar performance by an improved receiver. It was planned to use the new Telefunken LV 4 wideband double pentode for the rf preamplifier and the first mixer of the receiver. However, Telefunken had problems with the development of the LV 4 double pentode, so after all Siemens & Halske used the Philips EFF50 for the receiver front end of the “Jagdschloss” surveillance radar.  .

 The technical manual 11-219 seems to be derived from the original document:

 

OEMsr 411 - 95 , Survey of German Radar from the Countermeasures Point of View

 Originated by the Radio Research Laboratory of the Harvard University, September 4, 1944  

operating under Supervision of Office of Scientific Research and Development; National Defense Research Comnittee, Division 15 of Radio Coordination.

 It seems to be an updated version of the Document OEMsr 411 – 95 !

I havn’t found before any information that an alternative hard tube modulator (with the RS 323 tube) exist for the FuG 200 Hohentwiel airborne radar ?

 

My best wishes

  

Hans J

I would like to add: That already Chester W. Rice of GE in the US dealt with a PPI like system. And, would like to say: "PPI was alerady in the air:. He described a PPI like radar in 1936, be it without range measuring in the PPI display, as this was read-off a display panel (regard my contribution Radar II.)  

  

 

In September 2011 we have obtained from the UK the original Jagdschloss transmitter module

 

Jagdschloss transmitter codename Eibsee

Please consider our:  new dedicated transmitter webpage to this transmitter

 

Prinzipbild - Jagdschloss

Ln.- Ausbildungsstab 2

Zeichnung B/F 231 date 26.7.1944

Please click on this drawing as to open it in pdf

Please notice that you can print the full schematic at a single A4 sheet by using the option in "Acrobat Reader " print what you see at your screen" thus befor doing this adjust the size of the schematic at you computer screen!

 

List of Jagdschloss codenames (Tarnnamen)

 

When we consider the valve types engaged we can see that only LS50s - LV1s - TS41s - EF14s - SD6s and RV12P2000s are being employed (neglecting the single REN901 triode). The advantage is obvious, because service stocks could be kept very rationalised.

 

 

 

Please consider also the new: Jagdschloss TX and system page

Back to or proceed with: Report TME 11-219

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