R47W ARRL AiiIcmeui Eest iiiKl iflrMC

highly rtganied Infri mi tuitenna ruikl.inii'innlv r.^i.i = 11----11ii luiea. iksipn ukl I urn;

utenim 530,00

WGPfl7i07 All Ahim \mlDhI .Vnicmi^ hy

W ilhjm Ort QirapnflvTHjvc Lino-J^: uf jrruiptf fVKfn-rjuuijMiis. Si !.95 WGPSTiM: Beam Antenna Handbook by WHtei ur znd Sluan Qm Hx«rydiing ncoi «3 knm iSm l^iin des^a conunxticm. ad oproiHir ni SB

V. Gl^ 7077 SLrnpk1. \nt Wfce Antenna* 1

,ViiLutLiir!i by W'llllijun (Jdriind slu^n ( l^ iiT. v tiN mtitti-hand aniemu^, iEit;iqx!iisivLL kvuiii. 'ijUT-il iLi■" jiptennas for tiainSi in 'luujih ' I -i tLi. ui-.

liuml liXuig ..ill) he your liclui va low-Kind sul^c^ (X)

Homing in

Number 52 on your Feedback card

Joe Moell RE, K0OV PO Box 2508 Fuilerton OA 92633

More About Hamcon/ Foxhurtt-95

"Wc need more young people in ham radio!" Wayne says il. I've said it, and you have probably said it, too. What if 1 told you that there is a way Tor kids of almost any age to learn about radio without realizing the> ¿ye bein^ educated, while they have so mueh Inn the) won't want to stop/ They'll also he getting lots of fresh aii and exercise, far more than they would get silling in front of a computer screen. Bc>l of al). the kids don't need to be licensed; thes can sta:t immediately.

Yes. such an activity exists. In some eastern Ruropean an* I Asian countries, il is .so popular ihat it's part of Physical Education in schools. The sad fact is that it's rarely done stateside, i iains in our education industry haven't dis-eo\ered il yet. This best-kept secret is a sport called fox hunting/*

Hide-and-Seek With Radios t nlike more familiar mobile ^T-hunts," an international-rules foxhunt is an on-foot search for several concealed mini-transmit* ters in a large outdoor selling, Kids love it. and so do adults. I explained the concept in detail in Inst month's "Homing In/' I also began the story of Hamcon/ Fbxhum95, Southern California's

Photo A, Fox #3 was next to the long staircase on the edge of Batteries John Bartow and Saxton, an abandoned WW! shore defense sire at Fort MacArthur. One hunter hasn't realized yet that he is standing on top of it.

Radio Direction Finding first international-style radio direction finding [RDF) championship. It was d September 3 on the Fort Mac Arthur Military Museum grounds in the San Pedro area of Los Angeles. 1 served on ihe committee of Southern California Six Meter Cluh members who put on this 2 meter event for the 1995 ARRL Southwestern Division convention.

Hamcc11xhunt-95 simuiated as closely as practical a turopcan/ Asian foxhunt. Our rules were based on Internationa) Amateur Radio Union (1ARU) rules for direction- finding championships. I"nlike LARU events, there was no separate di\ is ion for women and competitors in ail divisions were required lo search for all foxes. Age divisions were different from i ARL" classifications.

International-style foxhunting is new to Southern Col forma, but that doesn't mean all Hamcon/ Foxhvni-yS participants were complete greenhorns. Many of the forty w ho signed up were experienced mobile 1-hurucrs who had learned techniques for "snuffing" out transmitters on footh whereas others had never tried RDF before, How could we put on a hunt that challenged the experienced f-hunters but ga\e first-timers a chance to do well?

The fox-hiding subcommittee decided to put out six foxes. Two transmitters would he easy to find, two would be really tough, and lwro would be in-between. Poxes and were intended to be the easy ones. We hid #6 under the concrete cover of an abandoned. 40-> ear-old nnde? ground command post for Nike defense missiles on a hilltop 9(10 feet southeast of the start point. The antenna for Fox #2 was N6VII s horizonlaldipolc in a nee 400 feet west ol the finish line. Both ol these foxes were high and in the clear, relatively speaking, hunters should have gotten sharp bearings.

tARlJ rules require red and while flags (called prisms) next to each fox. They arc appropriate in the deep-cover forests where

\sorld championships are held, but they would have been far too conspicuous in the fort areas, So we did not use them. The bright orange punches wilhin five feet of each I ransmitier were easy to spoi and pro-\ ided sufficient visual identification.

Fox #3 was

Photo H. The most dastardly fox hiding spot was deep inside this drainage channel, 200 feet from the beach. The orange card-marking punch is just barely visible in the wail-climbing plants.

supposed to he vers hard. It was on the steep slope of a 50-foot-decp football-field-siied pit that used to he part of a World War t mortar emplacement (Photo A)- its antenna was a twin-lead J. most ol which w as buried a couple of inches i mo the dirt next lo the long stairs. The idea was to "light up" the entire pit with lots of RF and create many signal reflections. The ultimate challenge was Fox #4, which was underground* five feci into a sea-lcvel drainage channel near the southern end of the park (Photo BK All foxes except #4 were at least 50 feet from the nearest trail.

The shortest possible route re ached the foxes in the following order: #3, #5,#6, #t.#4. #2. Hunters traveling that route directly would have gone 1.35 miles. This is about one half of the shortest route in a typical IARU championship foxhunt. Of course, nobody's route was close to being that short. Overall winner Scot Barih KA6UDZ found all foxes in 66 minutes and Senior Dhision iover age 46> winner Marvin lohnston KE6HTS did it in 76 minutes (PhotoC). B> comparison, a Hungarian and a Russian completed a much longer five-fox 2 meter course in just 47 minutes at the 1994 World Championships in Sweden.

According to the fox-hiding corollary in Murphy's Law; "Everyone will easily find the foxes that you think will be hard, and vice versa.11 The pit didif t creaie a pool-table effect for Fox #3 signals. Eighteen hunters found it.

()n the oLher hand, the high horizontal dipole of Fox #2 must have caused some unusual signal reflections. because man\ hunters reported that bearings to il crossed on top of a hill 400 feet northeast of it, The fox found by the most hunters I 28) was #5: the one found b> the fewest hunters iS) was #1, Both had been expected to he medium difficulty foxes.

This foxhunt was the last event of the convention, on Sunday afternoon. All da\ Saturday. a half dozen or so 'micro-Ts transmitted for a few seconds each from hiding spotN around the Queen Mary convention site, including the hotel, exhibit area, and parking lot. This gave everyone a chance to check out RDF gear and practice techniques.

A few eager entrants didn't wait until Saturday to get ready. Rick Barrett KE6DKF. who

Photo C\ Marvin Johnson KE6HTS picked this high spot overlooking the ocean 10 take a bearing. He took first place in the Senior Division.
0 0

Post a comment