====== P-716: SCR-269 Radio Compass ====== **SCR-269 Radio Compass**; manufactured by Fairchild Electronics. {{:images:p-716-bw.jpg?direct&400|P-716: PCR-269-A}} ===== Technical data ===== * [[Principle]]: automatic radio compass * [[Operation modes]]: [[A1]] (SCR-269-C only), [[A3|AM (A3)]] * [[Frequency range]]: 200 - 1,750 kHz (three ranges) * [[Sensitivity]]: [[A3|AM (A3)]] / [[Selectivity]]: ==== Power supply ==== * [[Mains operation]]: (115 V) * [[Batteries]]: 24 V, 12 V on-board power supply via converter MG-149-F ==== Dimensions ==== * Main unit BC-433-A: 200 x 305 x 500 mm, 21.25 kg * BC-434-A control box: 190 x 190 x 94 mm, 1.7 kg ==== Components / accessories ==== * Main unit BC-433-A * Control Box BC-434-A, two * Loop Antenna LP-21-A, housed in an elegant streamlined metal cabinet * Display instrument I-81-A and I-82-A * Relay BK-22-A ===== Station material ===== {{ :images:p-716-radiocompass.jpg?direct&300|P-716: SCR-269-A}} The SCR-269 radio compass was used in aeroplanes for navigation, the weight of the entire system is 33.2 kg. When tuned to a (long wave) beacon of an airfield or a radio (broadcast) transmitter (medium wave) on a known frequency, the corresponding bearing is shown in the display instrument. The pilot flies in the direction with a course deviation of 0°; when flying over the transmitter, the display changes to 180°. The system consists of the actual BC-433-A receiver, one or two BC-434-A control units, the motorised adjustable loop antenna in a streamlined radome and accessories. ===== Technical principle ===== ==== Tube configuration ==== two VT66, one VT-74, four VT-86, one VT-87, two VT-93, one VT-94, one VT-96, one VT-105, two VT-109 ==== Development ==== In 1942, the SCR-269 radio compass developed by Fairchild Electronics was introduced in the US Air Force. ==== Deployment ==== Emergency landings by B-24 Liberator bombers also made the technology of the radio compass known in Switzerland. After the end of the war, several systems were purchased; two complete systems (in order to be able to determine the location more precisely by double direction finding) were installed in each of the three Ju-52 aircraft, and two further systems in the Beechcraft C-45 of the Swiss national topography. Eight SCR-269 G systems were thus procured after 1945. {{gallery>:images?p-716*.jpg&0&80x80&crop&lightbox&showtitle&titlesort}} ===== Technical documentation ===== ==== Further information ==== * [[https://www.radiomuseum.org/r/fairchild_radio_compass_scr_269f_g.html|SCR-269 on the website of www.radiomuseum.org]]