80 m Fox hunting Receivers Keith Witney VE

80 m Fox hunting Receivers Keith Witney VE 7 KW Les Tocko VA 7 OM Amel Krdzalic VA 7 KBA 2018 -03 -19 BCRadio. Sport 2016 1

ARDF Foxhunting Let’s Walk before we Run! SARC meet 2018 -03 -19 BCRadio. Sport 2016 2

ARDF Foxhunting • Why? • Find noise or interference sources • Build some simple equipment • Get some exercise • Terrain/propagation effects • Navigation • Introduction to Amateur Radio for nonhams 2018 -03 -19 BCRadio. Sport 2016 3

ADRF Foxhunting • What is it? • Transmitters are hidden in a Park • Scored on number of transmitters found and the time taken. 2018 -03 -19 BCRadio. Sport 2016 4

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, Fox. Oring and Scout modes 2018 -03 -19 BCRadio. Sport 2016 5

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, MO 5 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. 2018 -03 -19 BCRadio. Sport 2016 6

2 m 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 2 m Handhelds with attenuator and signal indicator but they have some limitations 2018 -03 -19 BCRadio. Sport 2016 7

2 m ARDF Receivers VE 7 KBA • VK 3 YNG commercial receiver 2018 -03 -19 VE 7 GVS • Handheld setup (Elements folded for storage) BCRadio. Sport 2016 8

80 m Foxhunting • Receive equipment is less bulky • Effective sense antenna • Sharp null • Different but fewer propagation effects • Easier? 2018 -03 -19 BCRadio. Sport 2016 9

80 m ARDF Foxhunting Receiver CW Home built (loop and sense antenna) Les VA 7 OM Based on DF 1 FO receiver board 2018 -03 -19 BCRadio. Sport 2016 10

ARDF Foxhunt • Location • Public Park • International 10 km by 10 km • 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. 2018 -03 -19 BCRadio. Sport 2016 11

ARDF Foxhunt 2018 -03 -19 BCRadio. Sport 2016 12

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” 2 m equipment • Poor attenuators, AGC and limiting make hunting difficult • Reflections and multi-path • Beginners find 80 m hunts easier • Cheap Chinese radios work but can be confusing • Tuning and attenuation need improvement 2018 -03 -19 BCRadio. Sport 2016 13

Our solution • Use 80 m • No multipath • Smaller receivers • Use mini-foxes and Sprint cycles • Low power, simple to set-up • Small hunt area (100 m radius) so 500 m by 500 m • 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 2018 -03 -19 BCRadio. Sport 2016 14

Implementation • Les VA 7 OM designed a custom receiver. 2018 -03 -19 BCRadio. Sport 2016 15

Implementation • Les and Joe developed a mini-fox with the sprint cycle which could be easily deployed 2018 -03 -19 BCRadio. Sport 2016 16

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 minitransmitter • 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 2018 -03 -19 BCRadio. Sport 2016 17

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. 2018 -03 -19 BCRadio. Sport 2016 18

Receiver Kit • direct-conversion receiver with 4 -pole filter • voltage-variable tuning capacitor to adjust the frequency from 3550 to 3600 k. Hz. • 9 V battery • Ferrite loop antenna for a sharp bi-directional null with switchable sense antenna for direction determination • 4 step attenuator. • Total dynamic range >120 d. B 2018 -03 -19 BCRadio. Sport 2016 19

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 2018 -03 -19 BCRadio. Sport 2016 20

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 2018 -03 -19 BCRadio. Sport 2016 21

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 VE 7 KW ve 7 mid@telus. net (604) 475 -5254 2018 -03 -19 BCRadio. Sport 2016 22

And Afterwards? • BCRadio. Sport 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 BCRadio. Sport 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) 2018 -03 -19 BCRadio. Sport 2016 23

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 2018 -03 -19 BCRadio. Sport 2016 24

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 -3 m) 2018 -03 -19 BCRadio. Sport 2016 25

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 2018 -03 -19 BCRadio. Sport 2016 26

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. 2018 -03 -19 BCRadio. Sport 2016 27

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 • 2 m handheld (Rx only), W 2 HOL Directional antenna, offset attenuator • 80 m receiver Kit as offered above • 2 m receiver kit being developed 2018 -03 -19 BCRadio. Sport 2016 28

ARDF Foxhunt What Next? Participate for Canada at International Competitions • 2016 ARDF World Cup and World ARDF Championships in Albena Bulgaria August 299 September 2016 http: //ardf 2016. com/ • Region 2 ARDF Championships Killeen Texas April 6 -10, 2016 http: //homingin. com/farsnews. html 2018 -03 -19 BCRadio. Sport 2016 29

ARDF Foxhunting For more information • IARU http: //www. ardf-r 1. org/ • BC Radio Sport http: //ardf. ca • 2 m • Antennas http: //theleggios. net/wb 2 hol/projects/rdf/tape_bm. htm • Attenuators http: //www. homingin. com/joek 0 ov/offatten. html • 80 m • Receivers http: //www. geocities. jp/chn_ardf/index. htm 2018 -03 -19 BCRadio. Sport 2016 30

ARDF Foxhunting For more information • BC Radio Sport www. ardf. ca • Homing In Site www. homingin. com • ARRL http: //www. arrl. org/news/ardf-update-foxes-fitnessand-fun-in-2010 • Ultimate Automated Doppler DF System http: //www. ahha-doppler. com/gpss. html 2018 -03 -19 BCRadio. Sport 2016 31