Atlantikwall Regelbau L480 - Radar Bunker with Socket for Wassermann S R...

this bunker is a Regelbau Type L480 this is a Radar Bunker for FuMG Wassermann S Radar,
The Wassermann S was mounted on a L 480 bunker.

Regelbau L480 with Wassermann FuMG 402 type radar.
The Wassermann radar is a German radar from the Second World War.
It is a long-range version of a Freya radar equipped with a large vertical antenna which could direct the beam very precisely up to 300 km.
This radar, which emitted in a wavelength around 2.4 meters, entered into service in 1942 and around 150 were built

The standard for this type of the blockhouse construction has become known as L480. The radar antenna consisted of a 40 meters tall steel cylinder with mounted antennae. This type of radar carried the name Wassermann S for Schwer (heavy). This enabled the management of approaching airplanes in the airspace within a range of 300 kilometers

The Wasserman radar was an early-warning radar built by Germany during World War II. The radar was a development of FuMG 80 Freya and was operated during World War II for long range detection. It was developed under the direction of Theodor Schultes, beginning in 1942. Wasserman was based on largely unchanged Freya electronics, but used an entirely new antenna array in order to improve range, height-finding and bearing precision.

Seven different versions were developed. The two most important versions are:

The radio measurement equipment FuMG.41 Wassermann L (German: Leicht = light) was a constellation of four Freya antennas on top of each other, mounted on a 40-metre-high (130 ft) rotatable steel lattice mast.
A later version was the FuMG.42 Wassermann S (German: Schwer = heavy). For this eight Freya antenna arrays were mounted on a 60-metre-high (200 ft) pipe mast in two columns, each four antennae high.
The combination of the antennae in this way resulted in a concentration of the radiated energy to a smaller beam, thus resulting in a higher radiated power in the main direction (Effective Radiated Power = ERP), without increasing the transmitter power. The result was a longer range. With the L-version the horizontal opening angle of the antenna array remained the same, but the vertical opening angle was reduced (so flatter radiation pattern). Because the horizontal opening angle was not changed, the bearing measuring performance was not changed. With the S-version also the horizontal opening angle was reduced, with a better bearing resolution as a result.

Freya was an early warning radar deployed by Germany during World War II; it was named after the Norse Goddess Freyja. During the war, over a thousand stations were built. A naval version operating on a slightly different wavelength was also developed as the Seetakt.

First tests of what would become the "Freya" were conducted in early 1937, with initial delivery of an operational radar to the Kriegsmarine in 1938 by the GEMA company. Freya supported an early version of Identification friend or foe (IFF). Aircraft equipped with the FuG 25a "Erstling" IFF system could be successfully queried across ranges of over 100 km.

The "AN" version gained a switchable phasing line for the antenna. Switching in the phasing line led to a phase displacement of the antenna's radiation pattern and with that, a squinting to the left or right. This enabled the system in effect to switch from the rather broad "scanning for maxima" to narrow lobe switching. In that mode, a skilled operator could achieve an angular resolution of 0.1°.

The Freya radar was more advanced than its British counterpart, Chain Home. Freya operated on a 1.2 m (3.9 ft) wavelength (250 MHz) while Chain Home used 12 m. This allowed Freya to use a much smaller antenna system, one that was easier to rotate, move and position. It also offered higher resolution, allowing it to detect smaller targets. Because of its complex design, only eight Freya stations were operational when the war started, resulting in large gaps between the covered areas. The British Chain Home radar, although less advanced and more prone to errors, was simpler, which meant that the complete Chain Home network was in place in time for the Battle of Britain.