1. Radio Direction Finding
Hap Griffin WZ4O

2. Why Fox Hunting? Practice for real events…such as…
Downed aircraft via ELT
Finding lost or injured parties with radios
Finding jammers
Finding interference
It’s fun!

3. In some countries, direction finding is a competitive sport.

4. Techniques Signal strength plotting
Directional antennas (peaks or nulls)
Loop antennas (nulls)
Body fade (nulls)
Time Difference of Arrival (TDOA)
Doppler

5. Beam Antennas – Yagi
Optimised for F/B ratio

8. Loop Antenna – Sharp null broadside to loop

11. Active Attenuator