DIRECTION FINDER TC-5400 SYSTEM

 

 

1.1                         GENERAL DESCRIPTION

1.1

The TC-5400 Series of general purpose automatic direction finder systems are intended for use in a variety of military, commercial or civil government applications. The model   TC-5400 Series DF systems may be configured with a series of internal or external receivers and are compatible with a wide range of simple or sophisticated RF receiving instruments to include surveillance or amateur radios, spectrum analyzers or communications service monitors. The TC-5400 Series DFF Processor may be configured with a wide range of associated general purpose or mission specific fixed station, mobile, shipboard or airborne Direction Finder Antennas.

Standard and optional features include a built-in test  (BIT) circuit that evaluates the DF processor and antenna for proper operation each time the processor is turned on, a low battery indicator, and a signal strength display which provides proximity information on target signals.  Additional operator control functions   provide for ground or aircraft deployments, an adjustable threshold for radio net exploitation and a bearing offset control to electrically align the DF antenna for installation variances from true north or a vehicular heading reference.   A keypad and rotary tuning knob are included on the TC-5400-1 Series DF Processor/Receiver.  Receiver functions are controlled, and operating parameters are set by the operator at the keypad. 

 

OPERATION

 

TheTC-5400 Series DF Processors are general purpose, microprocessor based, automatic direction finder systems. These systems utilize a patented, non-disruptive, phase/amplitude processing technique to measure and display the relative bearing between the antenna array and radio transmission source.    Relative bearing information is displayed on a circular compass display as well as on a 3-digit bearing readout.  The 3-digit readout provides azimuth information with 1-degree resolution.  The LCD display also shows all DF Processor operating parameters selected by the operator. The basic system operates against AM, FM, CW, PM, Pulse and SSB modulation. The model TC-5400-1 Series include a built-in receiver with AM, NFM, WFM, LSB, USB and CW capability.

 

 

1.2      SPECIFICATIONS, DF PROCESSOR

 

DF processing technique.............................. Phase/Amplitude electronic rotating goniometer, digitally processed

Frequency Range.......................................... 200 kHz - 3000 MHz, limited by the receiver and DF antenna 

Signal formats (modulation).......................... AM, FM, SSB, CW,

Signal Bandwidths......................................... 200 Hz through 10 MHz  determined directly by receiver

Sensitivity                                                        6 dB signal-to-noise ratio for a bearing indication

Instrument processing accuracy................... ± I degree

Instrument processing resolution.................. I degree

Response time.............................................. better than 80 msec   

Calibration                                                       Automatic, Internally generated signal simulating 0 degrees

Front Panel Controls

Power  ........................................................... On (Unit turned off at Display /Control touch-screen)

Volume:......................................................... Rotary control knob for internal receiver or factory integrated external receiver(s)

Front Panel Displays......................................Color LCD Touch-screen for control and display

     Line of Bearing

           Digital................................................... 3-Digit, I resolution

           Circular Display................................... Compass pointer, 1-degree increments

           True/Relative....................................... Selectable with COMP2 Option

     Mode.......................................................... DF or OMNI

     Antenna Mounting...................................... Air/Ground

     BIT ...........................................................Sequential LOB display per DF Antenna quadrant

     DF Speed.................................................. Fast/Slow/Track

     Bearing Offset...........................................

 

Rear Panel Controls...................................... None, Optional RS-232, NMEA-0183 (Specify format)

Inputs/Outputs

     Power Input                                                  +12VDC, 110/220VAC optional 

     Antenna Control......................................... (MIL multipin connector)

      RF Input................................................... TNC

      Remote Control (Opt).............................. DB-9, or DB-25 depending upon options selected

 

Processor Size.............................................. 5.25" high x 19.00" wide x 22.00” deep                                                          

Processor Weight.......................................... 18 lbs. approx.

Environmental

     Temperature:

           Operating............................................. 0 degrees to +50 degrees C

            Non-Operating.................................... -10 degrees to +70 degrees C

            Humidity.............................................. 0 to 95%

 

Special Test Equipment................................ none

 

 

 

PRINCIPLES OF OPERATION

The TC-5400-1 DF Processor is a goniometer type direction finder that uses a variety of DF Antennas.  The DF Antennas may be Monopole, Dipole, Log Periodic, Annular Slot or other beam former, or various combinations thereof.

The DF antenna array has an Omni-directional receive capability and during signal processing develops a minimum of four equally spaced beam patters, with a discernible front-to-back ratio.  The front-to-back ratio of each beam pattern and the crossover point of adjacent beam patterns determines the frequency at which the DF Antenna will provide optimum performance within each bay or frequency band.

The TC-5400-1 Direction Finder Processor is the controlling device in the direction finder system.  As the receiver is tuned to a desired signal, the processor generates four sine wave signals at a 124.8 Hz rate; each at a 90 degree phase shift from the preceding or following sine wave. 

The received signal is AM modulated by the processor-generated sine wave, at each output (quadrant) of the antenna.  The signals are combined and fed to a receiver where it is AM detected.   The audio base band contains the 124.8 Hz and other received signal characteristics.  The AM detected signal is fed to the TC-5400-1 processor that selects the 124.8 Hz component, measures the phase angle relative to the reference phase and converts it into bearing information.

The processor then adds to the bearing information any offset programmed at the front panel, and displays the resultant bearing in a 3-digit readout and a corresponding relative compass pointer.  The processor continues to measure and update the front panel display at the selected slow or fast rate until the received signal is no longer present.   At signal loss, the processor 124.8 Hz component is no longer present.  At the loss of the 124.8 Hz component, the display is frozen, displaying the last bearing calculated and the processor resets until a new signal is present.