FOX HUNTING AND ITS EVOLUTION



Radio Direction Finding, Bunny hunting, T-hunting, Amateur Radio Direction Finding is all the same known by different names, has been a very popularly growing Radio Sport

RDF IS BORN

It is May 30, 1916, the eve of the great naval battle of the World War I, Jutland. A chain of Radio 
Direction Finding (RDF) stations along the east coast of England detects unusual movements 
of units of the German High Seas Fleet. Admiral Sir Henry Jackson, First Sea Lord, acting on 
this information, commits the British fleet to action. RDF has come of age.

Ask anyone about RDF and you will probably get as many different answers as, the average person 
thinks it, likely to be locating Spies with clandestine operation, pirate radio station etc. 
Hams and CBers will think of the Monitoring OR FCC Depts.' Van loaded with Radio locating 
equipment looking for illegal or bootleg operators, a lost Pilot, Boater, Hiker, etc., 
can be found in time trouble with RDF.

Ham Radio RDF, commonly known as ARDF, T-Hunting, Fox Hunting, or Bunny Hunting, 
both for sport and serious use has become very popular world over.

THE VERY BEGINNING

Directional antennae date back to the earliest days of Radio viz. Hertz, Marconi before 1900 to concentrate their
 transmitted energy. The earliest recorded work on the use of. antennas for direction finding was done by
 J. Stone in 1904 then on, improved by Bellini and Tosi, is the predecessor of Adcock of today.. 
Marconi acquired the patents in 1912 while F. Adcock 
patented his system in 1924 and began installing RDF equipment on commercial
 ships whichwould enable vessels to take bearings on known shore based 
wireless stations to plot their location.

During World War I there were many RDF antennas and equipments developed and
 improved which led to installing a series of RDF stations along the east coast of Great Britain arming the 
intelligence service of British Admiralty to track down German fleet successfully.

World War II enhanced the use of RDF by intelligence services on both sides and those 
in the middle to locate clandestine transmitters. Interestingly in Germany the secret service 
lacked sophistication, they made up a brute force, they would DF a signal down to a certain area of the town, then
 the transmitter would be located by turning off the power, block by block until it went off the air. Switzerland the 
only non - Axis country in central Europe was the hotbed of intelligence . activity for the Allied powers. 
The neutral Swiss counter intelligence force found itself Dfing transmitters from a number countries.

Japanese fear of DF caused strict radio silence to be observed. British Naval Intelligence DF efforts along with cryptography and traffic analysis, helped defeat the German U- boats across hundreds of miles of ocean.

HAMS AID THE WAR EFFORT

Though the hams could not operate their stations during the war, RDF techniques were used by 
Hams at Radio Intelligence Division (RID) of the FCc. Banks of receivers and special antennas were 
used to ferret out clandestine radio operations and assist pilots who were lost, disabled or forced down. 
About 75% of the employees there were Amateur Radio licensees. Many antenna systems were used 
and improved during this period which led to Linking of various RID sites for instant triangulation of bearings.
Mobile units and portable field strength meters called "sniffers" were also used to close in.

The System was very successful It resulted in about 400 unlicensed stations being put off air during the war 
and quickly stopped all attempts at subversive radio activities. In addition the system was called upon several 
times a day for fixes on lost aircraft, saving many Lives. It was only after the war that interrogations of the U-boars 
crews determined that, Germans were afraid to use their new super-radar. They were aware of the potential for Allied countermeasures and chose not to risk detection by turning their super radar.

RDF thus played a significant role in the Allied victor y at sea.

MILITARY RDF TODAY

In the decades since World War II, with the onset of Cold War, the intelligence services
 on both sides have installed large strategic DF systems. The most popular German 
technology the WuLLenweber system is being used world over by the National Security Agency.'
 A typical WuLLenweber system may have 96 broadband HF verticals set in a ring about a kilometer in diameter, the accuracy of the bearing is in the order of one half degree.

Another system called the ANjFLR-9 countermeasure Receiving System was built by 
Fischbach and Moore and installed in Southeast Asia in 1970 and later many around the world. 
It consisted .of 96 verticals in the outside ring in excess of 100 feet..

Other state of the art DF equipment uses various phase measurement, 
Doppler and interferometer techniques. One interesting system uses the time difference
of arrival ( TDOA ), where the exact, time of arrival of the signal is measured at three 
or more widely separated sites and the location determined by computer processing. 
Similar system can been seen at the Southern Region HQ of WPC in Perungudi located out skirts 
of Chennai in south India. Modern tactical OF systems usually at VHF UHF often use Doppler 
or Adcockj Watson-Watt techniques. Most of these systems are mounted on Jeeps, Trucks, 
tracked vehicles and aircraft although some could even be carried by personnel in the field. 
The latest being the state of the art communication intelligence ( COMINT) equipment is
 computer controlled. Many systems have digitally tuned receivers capable of scanning well 
over 500 channels per second. The received data would be processed in near real time 
and the location is determined.

SPORT HUNTING, FOX HUNTING, BUNNY HUNTING, ARDF

Dfing as a sport began to gain popularity in the early fifties as hams
 discovered the fun of having a ham station in the family car. Mobiling became a
 new aspect of the hobby. While adventurous hams tried the 6 and 2 meters in the VHF band, majority of them returned to the 75 and 160 meters in the HF bands.

Call it the T-Hunt ( Transmitter Hunt ), Fox Hunting, Bunny Hunting, 
ARDF (Amateur Radio Direction Finding) became very popular. Hunters used the loop
 of some sort but many hunters tried their ingenious devices, while advanced hunters used 
rf amps to over come the low sensitivity of the loop antenna.

Today 2 meter FM has taken over and has become the most popular Dfing all over the world.
 This can be far more challenging than HF hunting because Vhf reflections from hills and buildings 
are more pronounced.

From the outset, the quad or beam was the ham's antenna of choice for Vhf DFing. Hams are 
certainly not using the latest hush-hush military technology in their Dfing gear, but have certainly
 improved and developed Dfing technology. Commercial Dfing units are also available for hams,
 while the technology of the Doppler OF units for example have been around for sometime.

In many ways Transmitter Hunting hasn't changed a lot over the years. It's educational, potentially 
life saving and a lot of fun & sport. Club events, National Fox Hunts & International Fox hunts are
 being held regularly and professional hams ( hunters categorized into age groups are formed) 
for various competitions. Foxing hunting is done on Mobile and on Foot in open parks and 
estates etc. This year's International Fox Hunt is being held in China.

FOX HUNT IN INDIA

It was in the late 70s and early 80s when a few OX hams from Germany visited the BARC

Ban galore Amateur Radio Club meeting and spoke of the 80 meter fox hunting that kindled 
the enthusiasm here, but as usual the lack of proper techniques, portable Hf rx etc. put off the 
sport for some time and it was only in the late 80s when the VH F band became very 
popular and most of the hams were active with Vhf handy, that the enthusiasm rekindled. 

The first known and recorded Fox Hunt in India was held in Bangalore on 9 April 1989, the 
Fox was VU2TS OM Ganesh located himself behind the Jakkur Flying Club on the outskirts 
and more than 11 teams took part, thus FOX HUNTING was born in India with Bangalore as
 traditionally being the First for many Ham events and achievements.

Since then the Fox Hunts have improved, Bangalore has held more than 11 Day Fox Hunts,
 4 Night Fox Hunts, again the First to conduct the First Night Fox Hunt on 5th Nov 1994. 
Though other parts of India have slowly advanced only little information is that Madras has 
had about 7-8 Fox Hunts, Kerala about 4-5, Mysore, Coimbatore, Kodaikanal, 
Calcutta & Mumbai, more recently Mangalore also, have had just a couple of such events.

Bangalore has finally decided to host the First National Fox Hunt scheduled to be 
held in the New Millenium 2000 around Bangalore, it has been proposed to hold it more
 on International format & rules, with various categories, 2 sectors, first sector will be
mobile hunt to take the hunters outskirts and the second sector will be on Foot within a 
farm or estate or open no -mans land. Second sector hunt on foot will be to locate 3 or
 more hidden transmitters within the least time. The Hunt is open to licensed and Non
 licensed Amateurs which means even a person with just a receiver and directional 
antenna can take part.

With a view to promote the active participation in large numbers BARC has commenced workshops 
& kits to build various gadgets like the attenuators, beams & quads, loops, etc, to improve 
one's Dfing systems and conduct mock fox hunts.

In general Bangalore the Garden City of India will be the right host to such events and
 will attract entries from most parts of South India due to its central location and convenience of 
amenities Hi! (events like the recent Hamfest India' 98 have proved the capabilities of 
the hams of this city and the large participation by hams from all over India and abroad) 

The earlier Fox Hunts in Bangalore have attracted many teams from Chennai , Mysore & Kerala. 
And now Bangalore extends its warm welcome, inviting many more teams and participants for its
 First National Fox Hunt.