95-30-00  DIRECTION FINDER SYSTEM Back

  1. System Function
    2.
    The Direction Finder (DF) system is a stand-alone system designed to home in on the following transmissions:
    • COSPAS-SARSAT beacons at 406.025 MHz
    • Standard beacons transmitting at 121.5 and 243 MHz
    • Maritime VHF FM channels 16 and 70
    • ARGOS beacons
    • Any transmissions in the 100 to 400 MHz frequency range

  2. System Components
    3.
    The primary components of the DF system are the:
    • The Control Unit BC-124F (V2) (Ref. Fig. 1 and Fig. 4)
    • The Antenna MDF-124F (V2) (Ref. Fig. 3)
    • A Radio Magnetic Indicator (RMI) (Ref. Fig. 1 and Fig. 2)
    • Three ADF2/ DF switch/ annunciators (Ref. Fig. 2)
    • Two signal detection annunciators. (Ref. Fig. 1)
    The DF system also uses the Pilot’s and co-pilot’s existing RMI’s.

  3. System Operation
    4.
    The DF system uses Radio Frequency (RF) signals from a transmission source to measure the direction (bearing) to the transmission source. The direction of the transmission is indicated on a Radio Magnetic Indicator (RMI) on the mission console (No. 3 RMI). This RMI can display the same information as the No. 1 and No. 2 RMI’s I the flight compartment, that is:
    • Aircraft heading
    • VHF Omni-direction Finder (VOR) bearing to a ground transmitter
    • Automatic Direction Finder (ADF) bearing to a ground transmitter.
    The No. 1, No. 2 and No. 3 RMI’s display DF.

ATA imageATA imageATA imageATA image