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80m Fox hunting Receivers

80m Fox hunting Receivers. Keith Witney VE7KW Les Tocko VA7OM Amel Krdzalic VA7KBA. ARDF Foxhunting. Let’s Walk before we Run! SARC meet. ARDF Foxhunting. Why? Find noise or interference sources Build some simple equipment Get some exercise Terrain/propagation effects Navigation

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80m Fox hunting Receivers

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  1. 80m Fox hunting Receivers Keith Witney VE7KW Les Tocko VA7OM Amel Krdzalic VA7KBA BCRadioSport 2016

  2. ARDF Foxhunting Let’s Walk before we Run! SARC meet BCRadioSport 2016

  3. ARDF Foxhunting • Why? • Find noise or interference sources • Build some simple equipment • Get some exercise • Terrain/propagation effects • Navigation • Introduction to Amateur Radio for non-hams BCRadioSport 2016

  4. ADRF Foxhunting • What is it? • Transmitters are hidden in a Park • Scored on number of transmitters found and the time taken. BCRadioSport 2016

  5. ARDF History • RDF A Brief History • Gonimeter 1907 (directional Ant bearing) • Adcock arrays 1926 (Interconnected vertical ) • Doppler Radio systems (electronic rotation) • ARDF History • 1950’s Europe as a school activity • First European Championship 1961 • IARU standardized rules 1993 • 2004 games; 400 athletes, 29 countries 4 continents • NA mainly mobile interference location training (1970’s) • Friendship Radio Sport Games Victoria 2001 • Recently added Sprint, FoxOring and Scout modes BCRadioSport 2016

  6. ARDF Traditional Foxhunting • How does it work? (Traditional ARDF) • The transmitters are on for one minute each in sequence so it takes 5 minutes for a cycle. • MOE, MOI, MOS, MOH, MO5 all on the same frequency Identified by slow speed Morse (can count E, I, S, H, 5) • There is a continuous beacon (MO) at the finish for International competition on a separate frequency. • You find the transmitters by taking directional bearings, observing signal strengths and ultimately searching for the “flag” • The flag has a punch (or electronic reader) used to mark your score card. BCRadioSport 2016

  7. 2m Foxhunting • Propagation Challenges; Straight Line, but … • Multipath • Masked by Terrain and Conductive Objects • Water Refraction • Horizontal Dipole Transmitting antenna • Easy to build antennas • Can use 2m Handhelds with attenuator and signal indicator but they have some limitations BCRadioSport 2016

  8. 2m ARDF Receivers • VE7KBA • VK3YNG commercial receiver VE7GVS • Handheld setup (Elements folded for storage) BCRadioSport 2016

  9. 80m Foxhunting • Receive equipment is less bulky • Effective sense antenna • Sharp null • Different but fewer propagation effects • Easier? BCRadioSport 2016

  10. 80m ARDF Foxhunting Receiver CW Home built (loop and sense antenna) Les VA7OM Based on DF1FO receiver board BCRadioSport 2016

  11. ARDF Foxhunt • Location • Public Park • International 10km by 10km • Local 2 km by 2 km • Eg Robert Burnaby Park • Map provided • Shows major paths and features • Topography is nice • Typically transmitters are hunted from paths. BCRadioSport 2016

  12. ARDF Foxhunt BCRadioSport 2016

  13. What have we learned? • We have been running fox hunts for five years • There is a need for a less strenuous, simple format • Five minute cycle is frustrating for beginners • Beginners get frustrated with “simple” 2m equipment • Poor attenuators, AGC and limiting make hunting difficult • Reflections and multi-path • Beginners find 80m hunts easier • Cheap Chinese radios work but can be confusing • Tuning and attenuation need improvement BCRadioSport 2016

  14. Our solution • Use 80m • No multipath • Smaller receivers • Use mini-foxes and Sprint cycles • Low power, simple to set-up • Small hunt area (100m radius) so 500m by 500m • Sprint cycle is 12 seconds on every minute so you don’t have to wait too long for your next bearing • Use stable, well attenuated receivers BCRadioSport 2016

  15. Implementation • Les VA7OM designed a custom receiver. • Les VA7OM designed a custom receiver. BCRadioSport 2016

  16. Implementation • Les and Joe developed a mini-fox with the sprint cycle which could be easily deployed BCRadioSport 2016

  17. Receiver/Transmitter Kits • Les Tocko with the assistance of Joe Young, Nick Massey, Dave Miller and Chris Scholefield has developed kits for the receiver and mini-transmitter • A fun project • The mini-transmitter enables practicing and testing • The kit consists of: • PCBs with surface mount devices pre-installed • All other components • PCB case with all required mounting holes as a set of PCB pieces for assembly and finishing • Assembly manual BCRadioSport 2016

  18. Transmitter Kit The microfox has 4 modes DIP switch selectable: • continuous (beacon mode) • regular 1/4 minutes • fast sprint • slow sprint Fox number and ID are preprogrammed to the processor. BCRadioSport 2016

  19. Receiver Kit • direct-conversion receiver with 4-pole filter • voltage-variable tuning capacitor to adjust the frequency from 3550 to 3600 kHz. • 9V battery • Ferrite loop antenna for a sharp bi-directional null with switchable sense antenna for direction determination • 4 step attenuator. • Total dynamic range >120dB BCRadioSport 2016

  20. Receiver/Transmitter Kits • Kit assembly meeting • To further assist people with the kits, it is proposed to offer assembly meetings • Provide advice and assistance for case assembly and component “dry fit” • Provide assembly jigs • Kit testing and familiarization • Training sessions • Introduction fox hunt BCRadioSport 2016

  21. Demonstration • Show the kit components • Receiver and finished receiver • Transmitter and finished transmitter • Assembly manuals available for view • A mini-fox has been turned on and the receiver is connected to a speaker system • Illustrate cycle and identification • Illustrate direction finding • Null and forward/back • Illustrate attenuation BCRadioSport 2016

  22. Kit costs Note that these “introductory prices” are being provided on a non-profit cost recovery basis to provide a way for people to try the sport with decent equipment • Receiver $90 • Transmitter $10 • Assembly course $25 For the Receiver and Transmitter, we will require a 50% deposit. Delivery is expected to be 2 months. To Order Contact Keith VE7KW ve7mid@telus.net (604) 475-5254 BCRadioSport 2016

  23. And Afterwards? • BCRadioSport has planned a series of events starting in May and others will be held by other groups such as SARC, BARC and ARFGS (Victoria). See www.ardf.ca for details. • The BCRadioSport events will be held in a variety of local parks, nominally every second week alternating between Sunday and Saturday and starting at 10 AM (finish at noon) BCRadioSport 2016

  24. ARDF Foxhunt • A typical “Hunt” This will be less formal for practice • Meet at the park 10:00 • Equipment is quarantined • Transmitters have been pre-hidden or are hidden by the participants . • Transmitters are turned on remotely based on the master clock and checked for operation. • Participants are given instructions and starting time • Close to the start time given, the participant picks up map/equipment and score card and after the start proceeds to a start point not visible to other participants BCRadioSport 2016

  25. ARDF Foxhunt • The hunter will take bearings on the fox which is currently transmitting, moving along a line to get bearings on all foxes. In 10 (2 for Sprint cycle) minutes a general idea of where the foxes are can be obtained. This enables a hunt strategy to be determined (optimal route) • The hunter then proceeds to the first fox in his plan, taking bearing on the other foxes as appropriate while his target is off the air. As he gets closer (signal strength and bearing closure) he will likely need to increase the attenuation. This works until you are standing over the transmit antenna! • You are not finished , you need to find the flag with it’s punch not the transmitter (The flag will be within 2-3m) BCRadioSport 2016

  26. ARDF Foxhunt • This continues until you find all of the foxes or run out of time (You have to be back in the time allowed or you DNF). • Stepping it up • Once you learn how to find the foxes, you are now working against the clock • Orienteering techniques help in taking accurate bearings , minimising distance covered, understanding the terrain which might be affecting your signals • Run BCRadioSport 2016

  27. ARDF Foxhunt • Stepping it down • Use teams • Enables sharing of equipment • Non technically interested people can participate • You can have a runner/mountain goat for us who stroll • Smaller area • Mobile Foxhunting • If there is interest in mobile only Foxhunting, this can be arranged but is really something completely different as different techniques can be used. BCRadioSport 2016

  28. ARDF Foxhunt What Next? • Try it! Open to all. Loaner equipment available or just observe. • Practice events a/p previous schedule • BARC annual fox hunt • SARC annual fox hunt • ARFS fox hunts (Victoria) • Collect your own gear • 2m handheld (Rx only), W2HOL Directional antenna, offset attenuator • 80m receiver Kit as offered above • 2m receiver kit being developed BCRadioSport 2016

  29. ARDF Foxhunt What Next? Participate for Canada at International Competitions • 2016 ARDF World Cup and World ARDF Championships in Albena Bulgaria August 29-9 September 2016 http://ardf2016.com/ • Region 2 ARDF Championships Killeen Texas April 6-10, 2016 http://homingin.com/farsnews.html BCRadioSport 2016

  30. ARDF FoxhuntingFor more information • IARU http://www.ardf-r1.org/ • BC Radio Sport http://ardf.ca • 2m • Antennas http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm • Attenuators http://www.homingin.com/joek0ov/offatten.html • 80m • Receivers http://www.geocities.jp/chn_ardf/index.htm BCRadioSport 2016

  31. ARDF FoxhuntingFor more information • BC Radio Sport www.ardf.ca • Homing In Site www.homingin.com • ARRL http://www.arrl.org/news/ardf-update-foxes-fitness-and-fun-in-2010 • Ultimate Automated Doppler DF System http://www.ahha-doppler.com/gpss/gpss.html BCRadioSport 2016

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