I posted the following on German radar detectors on the \"General Discussions\" board some weeks ago.

\">Roessler gives us 4 pages on this subject in his \"Geschichte des deutschen U-Bootbaus\" chapter 8.122. There was a lot more to this story than Metox and Naxos. Unfortunately most of the good ideas came too late and the Allies were usually one step ahead.

The most effective equipment collection put into limited production in late 1944 was the FuMB 37 Leros permanent antenna which combined the earlier FuMB 35 Athos for 9 cm and 3 cm radar and the 1943 FuMB Ant. Bali which covered the 0.75 - 3 meter range. Bali was a replacement for the portable Biscay cross which had to be dismounted for diving. The last 3 cm and 9 cm receiver first issued in May 1944 was called FuMB 26 Tunis, which was the successor to the FuMB 7 Naxos the prototype for which came out in June 1943. The Leros/Tunis rig had a range of up to 50 km. Various receiving sets were used for the VHF/UHF radar including French NVK-R 600A Metox, FuMO 30, FuMB Zypern, FuMB 9 and FuMB 10 Borkum.

The British went through 3 generations of airborne ASW radar sets. The 1.5 meter ASV appeared in late 1940 and was standard equipment on all ASW planes by spring 1942. The Kriegsmarine did not figure this out until summer 1942 when they rushed the combination Metox and Biscay cross into service. The Kriegsmarine then ran down some blind alleys in late 1942 and 1943 while the British had switched over to 9 cm radar. The Germans got hold of a 9 cm H2S radar in spring 1943 from a bomber shot down near Rotterdam which revealed the secret of the cavity magnetron after some months of experimentation. By Feb. 1944, it was discovered that the British were using a 3 cm. set.

The emission properties of the Metox circuit design were known and they were controlled by shielding. Subsequent sets had circuits designed for low emission. According to Roessler, the Allies never used the Metox emissions to find a U-boat.<\"

The use of active radar by U-boats was always limited to experimental applications. The use of active radar by a submarine is of limited utility anyway since the signal can be picked up long before the return echo shows up on the screen. The radar detector is always going to react first. This means submarine radar is only effective under limited tactical conditions and almost useless if the enemy is well equipped with radar detectors.

The XXI had the best sonar suite available in the war and also an up to date radar detector system.

Regards,
SuperKraut