At a guess the RF circulator with the diodes and perhaps the ferrite magnet in the box may be a input switch that prevents (all but a small portion of) the transmitted pulse from returning to the instrument. Most peculiar semi rigid coax 'delay line' The magic happens under that last cover you did not open. It connects the RF power transistor output to the stub radiator in teh cavity and this also feeds the received signal to the RX section via the box to box coax connector. The short coax behind the TX power section probably gates the TX on for each ping and it sends a self resonant pulse as there was no visible frequency generator.
This is the RF transceiver of a radio altimeter. Judging from the shape of the integrated transmitter antenna, this one must have come from Exocet or a similar size missile. The full system would also include the receiving antenna, which connects to the external RF connector, and the main power supply, control and signal processing box, which connects to the large multi-pin connector. The visible electronics at 17:30 is a UHF oscillator/power amplifier/multiplier. The modulation input is on the top left, it comes from the outside. The output is at the bottom right. There we see a conductor disappearing into the metal cavity towards the left -- there, hidden from view, there must be the final frequency multiplier, which feeds through filters to the transmitting antenna, through the rod protruding down in the middle of the cavity 4:50. Some of the transmitter signal is also picked up by the probe on the left of the cavity, near the white screws. This goes as the local oscillator input into the mixer. The mixer is the circuit at 12:30. The bottom connection is the local oscillator. The rightmost connection is the RF input from an external receiving antenna. The intermediate frequency quadrature output of the mixers (the two diodes) is amplified by the circuit in the little box 13:30 and that is the output of this whole box, which goes further to the signal processing elsewhere and from which altitude is computed.
@@BGTech1 One other thing I forgot to mention: the yellow cylinder at the top at 4:50 is a delay line for the received signal. (Remi has pointed this out in another comment, in french.) The additional delay helps to extend measurements to zero altitude. This fits with Exocet missile's capability to sea skim at an altitude of 1-2 meters.
Merci . un bel exemple du pourquoi la RF militaire c'était tres cher : tout cablé et soudé à la main. L'ajustage mécanique n'est possible qu'avec toutes ces vis. Mon premier plateau hyper thales 18Ghz en avait 125. Il fallait tout dévissé pour mettre au point un seul composant...Le coax est là , non pas pour faire une inductance, mais pour ajouter un delais et réduire la zone aveugle du radar. Le melangeur rate-race est en techno stripline et non micro strip. Comme deja dit, il y a une autre antenne . C'est du 4Ghz environ un radar FMCW je penses. la sortie du melangeur donne une fréquence BF qui est fonction de la distance à laquelle s'est réfléchie OEM. Il y a mélange entre l'onde emise et celle reçue, qui n'on' pas exactement la même fréquence ( ce n'est pas du dopler ) puisque'elle change en permanence et se propage. plus facile sur un dessin. C'est tres sioux de mettre au point un tel circuit car les composant traversants ne traversent pas et la longueur des connexion intervient sur le comportent : la longueur d'onde ne fait que quelques centimètres sur ce PCB.
Super vidéo, le coté ASMR du dévissage est juste parfait !
It's crazy how so much stuff in avionics looks like it was built in some random guys garden shed
At a guess the RF circulator with the diodes and perhaps the ferrite magnet in the box may be a input switch that prevents (all but a small portion of) the transmitted pulse from returning to the instrument.
Most peculiar semi rigid coax 'delay line'
The magic happens under that last cover you did not open. It connects the RF power transistor output to the stub radiator in teh cavity and this also feeds the received signal to the RX section via the box to box coax connector.
The short coax behind the TX power section probably gates the TX on for each ping and it sends a self resonant pulse as there was no visible frequency generator.
This is the RF transceiver of a radio altimeter. Judging from the shape of the integrated transmitter antenna, this one must have come from Exocet or a similar size missile. The full system would also include the receiving antenna, which connects to the external RF connector, and the main power supply, control and signal processing box, which connects to the large multi-pin connector.
The visible electronics at 17:30 is a UHF oscillator/power amplifier/multiplier. The modulation input is on the top left, it comes from the outside. The output is at the bottom right. There we see a conductor disappearing into the metal cavity towards the left -- there, hidden from view, there must be the final frequency multiplier, which feeds through filters to the transmitting antenna, through the rod protruding down in the middle of the cavity 4:50.
Some of the transmitter signal is also picked up by the probe on the left of the cavity, near the white screws. This goes as the local oscillator input into the mixer. The mixer is the circuit at 12:30. The bottom connection is the local oscillator. The rightmost connection is the RF input from an external receiving antenna. The intermediate frequency quadrature output of the mixers (the two diodes) is amplified by the circuit in the little box 13:30 and that is the output of this whole box, which goes further to the signal processing elsewhere and from which altitude is computed.
Great information!
@@BGTech1 One other thing I forgot to mention: the yellow cylinder at the top at 4:50 is a delay line for the received signal. (Remi has pointed this out in another comment, in french.) The additional delay helps to extend measurements to zero altitude. This fits with Exocet missile's capability to sea skim at an altitude of 1-2 meters.
Merci . un bel exemple du pourquoi la RF militaire c'était tres cher : tout cablé et soudé à la main. L'ajustage mécanique n'est possible qu'avec toutes ces vis. Mon premier plateau hyper thales 18Ghz en avait 125. Il fallait tout dévissé pour mettre au point un seul composant...Le coax est là , non pas pour faire une inductance, mais pour ajouter un delais et réduire la zone aveugle du radar. Le melangeur rate-race est en techno stripline et non micro strip. Comme deja dit, il y a une autre antenne . C'est du 4Ghz environ un radar FMCW je penses. la sortie du melangeur donne une fréquence BF qui est fonction de la distance à laquelle s'est réfléchie OEM. Il y a mélange entre l'onde emise et celle reçue, qui n'on' pas exactement la même fréquence ( ce n'est pas du dopler ) puisque'elle change en permanence et se propage. plus facile sur un dessin. C'est tres sioux de mettre au point un tel circuit car les composant traversants ne traversent pas et la longueur des connexion intervient sur le comportent : la longueur d'onde ne fait que quelques centimètres sur ce PCB.
Привет👋
Отличный аппарат 👍
Golden mistery device😎
lot of screws!
круче китайцев умели свч делать