Erstling IFF transceiver

The on-board radio equipment FuG 25a debut was built during World War II from 1941 in machines of the Luftwaffe, to allow for the own radar stations a friend or foe. The development of the company GEMA received the impetus of the German Freya and Würzburg radar stations and " replied " then with a fixed signal. The FuG 25a was later central part of EGON Jägerleitverfahrens.

Use

The debut - detection device was activated from the ground station by switching the pulse repetition frequency of 3750 Hz to 5000 Hz. The device " replied " then the radar station at 156 MHz with a programmed Morse code. As a code transmitter was a motor-driven cam switch. This was provided with two coding keys, which each represented a ten -bit code. For use together with Würzburg devices accessories were necessary: ​​one interrogator with the code name " Q- device" ( " cow " ) and the recipient identifier " chamois ".

Countermeasures

In the summer of 1944, the first British Mosquitos with the device " Perfectos " were fitted, which the FuG 25a activated and thus facilitated their detection. The utility of the "first " was so severely limited, since the German night fighter crews had to eliminate it as a countermeasure, the first- devices.

Specifications

• Receiver: 125 MHz ( Freya ) and 550-580 MHz ( Würzburg)
• Sensitivity: 2 mV
• Channel: 156 MHz
• Transmission Power: 0.2 Watt
• Activation: radar pulses at 5000 Hz
• Key: 2 x 10 bit

Safeguards

The German air force was known to be sensitive to devices such as this small explosive charges were placed. This should allow for self-destruction of the plant, before it could be captured by the Allies. A small fuse allowed the crew to get to safety in time.