1. SAR-DF 517 Search and Rescue 4-Band Precision Direction Finder
Operation User Manual
SAR-DF 517 Search and Rescue 4-Band Precision Direction Finder

2. Purpose of the direction finder
The SAR DF 517 modern precision direction finder was developed mainly for professional SAR (search and rescue) purposes. It has the ability to bear and analyse traditional emergency frequencies in the UHF and VHF bands, maritime radio channel 16, and the common COSPAS/SARSAT emergency signal. Because of its very short pulse length, the COSPAS/SARSAT signal bearing cannot be determined accurately using conventional direction finders.
This system incorporates our newly developed and patented antenna (small, rugged and wideband), as well as sophisticated bearing analysis algorithms, allowing delivery of a quick and steady indication.
The direction finder was developed for working under stressful conditions such as in an aircraft, helicopter or vehicle.

3. System Components Control-Display Unit (CDU)
Antenna-Receiver Unit (ARU)

4. Operation Power-On and operation modes emergency or training
(1) ON/OFF
(2) PAGE
(3) MODE Indication of the actual operation mode
(4) ARU Version Software version and serial number of antenna-receiver Unit
(5) CDU Version Software version and serial number of control-display Unit

5. General Functions
(1) DIM press REP while selecting the brightness level whit PAGE
(2) PAGE Use the rotary switch to select a page from 1 to 6

6. Bearing mode (pages 1 to 3)
(1) FREQUENCY Selected
(2) VOLUME
(3) SQL Should be above the noise level
(4) CLR For erasing the stored bearing value
(5) STORE While bearing an AM signal a 3 kHz sound is superimposed to the audio signal for technical reasons
(6) REPEAT Displays the last valid bearing value with the corresponding receive level

7. Display readings in BEARING mode
Page 1: 360°bearing
Page 2: expanded 45°
Page 3: bearing text
(1) Bearing value
(2) Spread Maximum deviation of unaveraged bearing. Good bearing results even with a spread of 45°as a result of the averaging procedure
(3) Receive level Field strength
(4) Squelch level Squelch level must be above the noise level without a received signal
(5) Offset Corrects for antenna alignment (adjusted in the edit-menu)
(6) Mounting TOP mounted or BOTTOM mounted antenna
(7) LS: ---:--- Internal timer (LS meaning last signal) indicating the time since the last signal was received, displayed in min /sec

8. Using the SCAN mode while bearing COSPAS/SARSAT signals
The COSPAS/SARSAT signal on 406,025 MHz is only transmitted every 50 sec (Pulse length of 400ms)
The scanning mode is possible with frequencies 406,025MHz or 121,500/243,000MHz or the matching training frequencies
The LS: ---:--- timer (LS meaning last signal) always displays the time since last COSPAS/SARSAT signal was received in MHz
Frequency displayed in scanning mode

9. COSPAS/SARSAT
Selecting this page automatically sets the active frequency on 406,025 MHz (or the matching training frequency)

10. Analysing the COSPAS/SARSAT continuous binary signal
(1) CLR Erases current message on display
(2) STORE Stores current message on display
(3) REP Currently-stored message will be displayed
(4) SYNC OK Satellite signal frame mode
(5) COSPAS/SARSAT Protocol
(6) HEX MESSAGE - SHORT
(7) HEX MESSAGE - LONG
(8) COUNTRY Numeric identification
(9) BEACON IDENT Identifies a registered transmitter
(10) GPS-LOCATION DATA Latitude and longitude
(11) Time Since the last valid COSPAS/SARSAT signal was received

11. System Configuration (1) SELECT the value to be changed
(2)  rotary switch to change the value
(3) STORE Pushbutton to confirm new values
(4) Range of adjustable values
(5) Time Hold Duration [sec] of internal storage of the averaged bearing value
(6) Offset Electronic correction (rotation) of the bearing antenna
(7) Mounting Order of antenna mounting
(8) Ext. Dimming Voltage Range

12. Setting the training frequencies
(1) SELECT Rotary switch selects the frequency to be changed
(2)  rotary switch to change the frequency.
(3) STORE Pushbutton to confirm changed values
(4) Range allowed for frequency setting
(5) Training frequency on maritime band
(6) Training frequency 1
(7) Training frequency 2
(8) Training frequency 3