Radar warning question

Chock · 05-05-07, 07:43 PM

While it is true that many U-Boats kept a old few devices installed, it's extremely likely that they'd have dropped the FuMB 1 'Metox' like a proverbial hot rock as soon as they could do, since it actually increased the chance of being detected as allied radar improved...

Check out this German report from 1943:

'Gruppe West reports, as a result of experiments., that the Metox radar interceptor produces radiation of its own, which can be detected at the following distances... 23km at 500m altitude, 33km at 1000m altitude and 50km at an altitude of 2000m.'

Incidentally this was way beyond the 'Metox' useful detection range, effectively making it a liability in many cases, rather than an aid - which is sort of fitting, since it was made by a French company!

Also check out this official order to all German subs sent in summer 1943:

'Use of the Metox and Grandin RWRs is now forbidden in all sea areas.'

With that in mind, the deletion of older RWR devices in GWX is broadly accurate.

In actual fact this emission problem was not the only issue with the early German radar detectors, which emitted an audio warning as well as a visual indication on an oscilliscope. It was often not realised that the audio signal was generated from the pulse repetition frequency of the detecting aircraft search radar. At high PRF it was quite possible for the RWR to generate a warning audio signal which was actually outside the range of human hearing, so if nobody was watching the oscilliscope, thinking they'd get an audio warning too, they'd be in for a shock!

ronbrewer · 05-07-07, 11:50 AM

The following link has some good info:

http://uboat.net/technical/detectors.htm

I know the "Metox transmitting detectable signals" versus the "Lie told by captured British officer" has been tossed around the forum for a while. I think the general consensus is that it was the introduction of 10cm radar (undetectable at the time by German technology) that was the cause of so many losses of 1943 instead of the Metox transmitting signals.

Thanks,
Ron

05-05-07, 07:43 PM	#1
Chock Sea Lord Join Date: May 2005 Location: Under a thermal layer in chilly Olde England Posts: 1,842 Downloads: 0 Uploads: 0	While it is true that many U-Boats kept a old few devices installed, it's extremely likely that they'd have dropped the FuMB 1 'Metox' like a proverbial hot rock as soon as they could do, since it actually increased the chance of being detected as allied radar improved... Check out this German report from 1943: 'Gruppe West reports, as a result of experiments., that the Metox radar interceptor produces radiation of its own, which can be detected at the following distances... 23km at 500m altitude, 33km at 1000m altitude and 50km at an altitude of 2000m.' Incidentally this was way beyond the 'Metox' useful detection range, effectively making it a liability in many cases, rather than an aid - which is sort of fitting, since it was made by a French company! Also check out this official order to all German subs sent in summer 1943: 'Use of the Metox and Grandin RWRs is now forbidden in all sea areas.' With that in mind, the deletion of older RWR devices in GWX is broadly accurate. In actual fact this emission problem was not the only issue with the early German radar detectors, which emitted an audio warning as well as a visual indication on an oscilliscope. It was often not realised that the audio signal was generated from the pulse repetition frequency of the detecting aircraft search radar. At high PRF it was quite possible for the RWR to generate a warning audio signal which was actually outside the range of human hearing, so if nobody was watching the oscilliscope, thinking they'd get an audio warning too, they'd be in for a shock!

05-07-07, 11:50 AM	#2
ronbrewer Mate Join Date: Jul 2005 Location: Dallas, TX Posts: 54 Downloads: 0 Uploads: 0	The following link has some good info: http://uboat.net/technical/detectors.htm I know the "Metox transmitting detectable signals" versus the "Lie told by captured British officer" has been tossed around the forum for a while. I think the general consensus is that it was the introduction of 10cm radar (undetectable at the time by German technology) that was the cause of so many losses of 1943 instead of the Metox transmitting signals. Thanks, Ron