T4 Electric
7500m/20kts
Falke, the first homing torpedo, was fitted with a passive acoustic homing device. It was introduced in March, 1943 and used by U-603 (Oblt. Bertelsmann), U-758 (Kptlt. Manseck) and U-221 (Kptlt. Trojer) against convoys HX-229 and SC-122. Few were used as it was replace by the T5 which was faster, had a greater range and could be used with either magnetic or contact detonators.
7s T5 Electric
5700m/24kts
The Zaunköning (Wren) came into service during the autumn of 1943. Intended to be an escort-killer, it achieved some early minor success only to be countered by the allied Foxer noise-making decoy. It was scoring hits against escort and merchants to the end of the war though.
The weapon was designed to lock onto the loudest noise after a run of 400m from its launch. This often proved to be the U-boat itself and standard issue-orders were to dive immediately to depth of 60m after launch froma bow tube while a stern shot was to be followed by a complete silence in the boat. Two U-boats were almost certainly lost when hit by one of their own T5 torpedoes, U-972 in Dec 1943 and U-377 in Jan 1944.
T11 Electric
5700m/24kts
A modified T5, less affected by Foxer. Never used in battle conditions although late test results were promising.
uboat.net - Technical pages
MG 42 G (gU)
FuMO 30
This was an improved version of the rotating mast version of FMG 41G (gU), with a direction finder added, ready in late 1942. It was built into all U-boats. However, it was easily disabled by depth charges or bombs, and the antennas corroded in the salt water. Commanders did not like to use it, because they feared that it gave away their position.
FuMO 61 Hohentwiel U
FuMO 65 Hohentwiel U1
Hohentwiel was developed for installation in aircraft, to be used against surface ships. The first working radar in this series appeared in September 1942, and from August 1943 onwards the radar was installed in naval reconnaissance aircraft such as the Fw 200 and He 177. Hohentwiel radars operated on 550MHz (55cm), and later models were tunable between 525 and 575MHz.
In 1943 Lorentz was instructed to adapt Hohentwiel for naval use, and soon Hohentwiel appeared on U-boats, small surface ships, and coastal installations. These Hohentwiel radars contained only 19 valves and, by the standards of the time, were easy to maintain and reliable. The U-Boat FuMO 61 version had a 1 by 1.4 meter rotating antenna (again an array of dipoles) on a mast. Size of the antenna and height of the mast were restricted by installation on an U-boot, and range was 10km against ships and 20km against aircraft; installations on surface ships had double that range. Resolution was about 3 degrees, and at short range its range accuracy was 100 meters. FuMO 65 replaced the traditional radar display, which had separate oscilloscope screens indicating range and azimuth, by a PPI (Plan Position Indicator) screen, known to the Germans as 'Drauf'. This is kind of radar display most familiar to us today, a circular display on which the position of a target is directly indicated as the radar beam sweeps round. FuMO 65 was installed in only a few Type XXI submarines. It was considered a very useful piece of equipment, especially for navigation in coastal waters.
FuMO 83 Berlin U I
FuMO 84 Berlin U II
The Berlin series of centimetric (9cm) radars, built by Telefunken, was based on the British development of the cavity magnetron, as found in a British bomber shot down near Rotterdam on 3 February 1943. This was a painful surprise for the Germans. Not only were they far behind in the development of centimetric radar, they had just abandoned it, in the belief that it would not be effective. Tests of the captured radar, code named Rotterdam, revealed its performance, and it was quickly copied under the name 'Berlin'. As was typical, the German copy was better engineered than its British equivalent, and thus considerably lighter and smaller.
FuMO 83 had four ceramic stub antennas (whatever those are?) in a plastic sphere, which was again installed on top of a rotating mast. It could be used for panoramic scanning or for direction finding. The system was tested on an U-Boot (alas it is not said which one!), and gave a view as "from a balloon 200 metres above the boat", according to its skipper.
FuMO 84 was the final version, which did not use a retractable mast. The system never went into production.
Ballspiel
Ballspiel was a gunnery radar for U-boats. Like most German radars at the end of the war, it was a development of Berlin. It had a range of 25km, but for practical gunnery only 8km was used. It had an azimuth accuracy of about 1 degree and a range accuracy of 500 meters. It is known that Ballspiel was used in active service, but there are no data about its effectiveness.
uboat.net - Technical pages