Samos (device)
Samos was the code name of a German radio measuring device used in World War II , more precisely a radio measuring observation device (FuMB) for ultra-short waves (VHF). The official military name of the device was "Fu MB 4" (often written: "FuMB 4"), while the manufacturer Rohde & Schwarz (R&S) gave it the type designation "RS 1/5 UD / 42 a", from which it derives Development year 1942 can be derived.
description
FuMB 4 (Samos) is used for reception of electromagnetic waves in a part of the FM frequency range (traditional 30 MHz to 300 MHz) and that of 90 MHz to 470 MHz in four switchable areas :
- Range 1: 90 MHz… 140 MHz
- Range 2: 140 MHz… 210 MHz
- Range 3: 210 MHz… 310 MHz
- Range 4: 310 MHz… 470 MHz
The measuring receiver works according to the heterodyne principle . The military designation FuMB 4 shows that there were other radio measurement monitoring devices. These include FuMB 1 (Metox) , FuMB 5 (Fanö) , FuMB 7 (Naxos) , FuMB 8 (Cyprus), FuMB 9 (Wanze), FuMB 10 (Borkum), FuMB 11 (Corfu), FuMB 26 (Tunis), FuMB 35 (Athos) and FuMB 37 (Leros).
use
Samos was used on airplanes, ships and especially on submarines to track down enemy radio measurement signals ( radar ) and, together with a suitable antenna such as the " Bali antenna " (picture), served the purpose of a radar warning device . In conjunction with a DF antenna such as the simple dipole antenna known as the “ Biscay Cross ”, the direction of the broadcasts could also be determined. Samos has a "Search" / "Bearing" switch for this purpose. The active in the search reception automatic gain control ( "regulated") is used to Peilempfang deactivated ( "unregulated") thereby allowing the used for direction finding minimum search .
Another application was the calibration of our own active radio measuring devices (FuMG), such as the FuMG 80 (Freya) . The FuMB 5 (Fanö) developed a year later by the same manufacturer can be seen as a higher-frequency supplement to Samos, whose frequency range covers 400 MHz to 1600 MHz.
Technical specifications
Back then as “ Secret! "Declared work script with the coded manufacturing code ncv (for R&S) you can find the following information:
FuMB 4 (Samos) | Specifications |
Frequency range | 90 MHz ... 470 MHz |
Frequency accuracy | 0.5 % |
Input impedance | 150 Ω ( symmetrical ) |
Intermediate frequency (IF) | 2.5 MHz |
IF bandwidth | 50 kHz |
sensitivity | 12 µV input voltage for 1 V output voltage at 4 kΩ |
Demodulations | AM and FM |
display | HF - or NF - voltage |
Mains input voltage | 220 V |
Grid frequency | 50 Hz |
Power consumption | 34 watts |
Dimensions | 515 mm × 245 mm × 300 mm |
Weight | 20 kg |
literature
- Arthur O. Bauer: Radio direction finding as an Allied weapon against German submarines 1939-1945. How weaknesses and failures in the radio control of the submarines contributed to the outcome of the “Battle of the Atlantic”. Arthur O. Bauer Selbstverlag, Diemen , The Netherlands 1997, p. 196, ISBN 3-00-002142-6 .
- Brian Johnson: Top Secret - Science and Technology in World War II. Motorbuch-Verlag, Stuttgart 1983, ISBN 978-3-87943-816-7 .
- Jochen Brennecke: The turning point in the submarine war - causes and consequences 1939–1943. Köhlers Verlags-Ges. 1984. ISBN 978-3-7822-0281-7 .
- Fritz Trenkle: The German radio measurement process until 1945. Motorbuch-Verlag, Stuttgart 1979. ISBN 3-87943-668-1 .
Web links
- High resolution photo
- Manual , scan of the authentic work script
- Photo with explanation of the operating and display elements
- Total current flow
- "Funkmeßgerätekunde" MDv. No. 291, Samos at pp. 53-57
- Detailed photo documentation (English)
- RS1 / 5 UD / 42a description
- www.radiomuseum.org
- On-board radios of the German Air Force 1939–1945
Individual evidence
- ↑ Werkschrift , accessed on June 18, 2019.
- ↑ Werkschrift , "Fundamental Properties", p. 3, accessed on June 18, 2019.