DDF2020M Radio Direction Finder kit requires minimum assembly for 10~15 Minutes
The DDF2020M DF is an economical but very sophisticated Doppler DF “kit” with a GPS input, and RS232 output to provide the ability to indicate its location and draw bearing automatically or manually on Google Earth map to find the RF transmitter more conveniently.
DDF2020M kit Includes eight assembled / tested PC boards: MAIN board, 2 Sub boards, and 1 antenna board in the main unit. Completion work is required by the user to finish the DF main unit. Guidelines for the completion work are provided.
The user must provide a NB FM receiver, 5 antennas with mounts for external DF antenna unit and a PC for DF bearing (Windows OS). DDF2020 display program further requires a GPS receiver with NMEA 4800 baud output.
VHF Doppler DF – 5 Antennas primarily for mobile DF, 100~1000 MHz
Economy, high performance DSP / micro processor design, software intensive
Sold as a kit – Main unit, antenna unit and associated cables
RS232 output for Windows PCs (Agrello format)
Uses modified Joe Moell Wideband Antenna design
9 ~ 28 VDC operation
Optional GPS Receiver available.
Rcvr Freq: Determined by user-provided FM receiver, range 100 to 1000 MHz
Antenna: Four elements for DF and one auxiliary element for improving sensitivity and accuracy, wave vertical with assembled
Ant Scan: Scan rate 430 Hz, rotation clockwise (viewed from above antenna)
Ant Switch: Modified Joe Moell Wideband Doppler DF antenna design
Employs Agilent HSMP3893 SMT PIN diodes
SMT / stripline circuit design, SMA output connector
Audio Input: FM receiver speaker audio, 1.0K ohm load. 25db dynamic range.
GPS Input: 4800 baud RS232 input, NMEA $GPRMC, $GPGGA and / or $GPVTG messages.
Output 1: RS232 Agrello DF message, 4800 baud, 8N2. (15 messages / second )
Ant Outputs : Four discrete active HIGH outputs for DDF 2020 Antenna ( one per antenna )
DC Power : 9 ~ 28 VDC
Voice Filter : Switched-capacitor filter, (SCF) 4 sections. Bandwidth 0.2 Hz
The MultiDisplay of DDF2020M provides a combined numeric and pelorus display in the main board. A high quality display, with 2 microcomputers and an RS232 input that accepts Agrello DF messages.
The pelorus display employs 36 high density LEDs, with 4 yellow LEDs at cardinal headings. Option straps allow “hold/blink” of last valid DF data, or pelorus “orbit” when data goes invalid. All LEDs briefly “flash” (2 second intervals) for enhanced nighttime viewing
3 digit numeric readout, 0.36 inch characters
36 LED pelorus display, 4 yellow cardinal LEDS
Selectable HOLD/ORBIT display for old DF data