Transcript BROADCAST DATA TECHNOLOGIES

DIRECTION FINDING
An Introduction
Agenda
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Why do we do it?
Getting Started
More developed techniques
What we do in WADARC
Rules
Summary
Why do we do it?
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It’s part of the Amateur radio hobby (sport)
It’s a chance to get outside and play radio
Encourages team building through competition
An opportunity to build equipment ( e.g attenuators )
Innovative antennas (e.g use flexible measuring tape)
An opportunity to learn about the district
Learn about signal propagation
End up at the pub!!
Getting Started (Fox)
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A rig capable of say 25 watts minimum
A decent portable power supply
Antenna and mounting pole
Good camouflage
Site capable of being heard at the start
Getting Started (Hound)
• Rig with battery power and illuminated signal level
meter
• A directional antenna which should be hand held
• Also be easily transportable in and out of a vehicle
• A map local to the area
• Ruler, pencil, rubber and protractor
• A compass, preferably a sighting one.
Getting Started (organiser/fox)
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Fix start time and location
Fix operating frequency (usually 145.300MHz)
Aim for a “run time” of about 90 mins
Fix your “QSY”
Optional mobile contact number
The Fox Hunt
• Organiser at the Start point calls the fox to check
point to point comms and give lead callsign of each
team.
• Hunt starts at designated time
• Hounds stop, take bearings, draw lines on map and
move on.
• Using attenuator take bearings until fox is found then
off to the nearby QSY
• Note: Be prepared for “outside” interest in the event.
Sample Configuration
• Hound kit is rig (with meter), attenuator and
directional antenna e.g HB9CV
• “In car” rig on main band with mag mount
• In car portable on main band with removable
antenna
• Third Harmonic rig for close in work
• Really deaf receiver (op amp) for well hidden foxes!
Sample Fox locations
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Under bridges
Under leaves
Under leaves in a dry ditch!
Antenna up a relay mast!
In a car park with steamed up windows!
In a car park with blow up dummy at wheel.
More Developed Techniques
• Doppler
http://www.eham.net/reviews/detail/1463
• Active antenna (VK3YNG)
http://www.foxhunt.com.au
http://www.foxhunt.com.au/2m_sniffer/manual.htm
What we do in WADARC
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Only 2M and 70cm contests
Practice DF to start the series
2M Trophy Eileen Medley
2M Revenge Trophy G8PMF Rose Bowl
70cm trophy to finish the series
All presented at the Construction and Presentation
evening and then engraved.
• More at http://www.wadarc.com
Rules
North Wales DF events
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Run in N.Wales on a Sunday by Tom G4BKF
Two events a year.
Takes all day..break for lunch
Starts at the Clwyd Gate 10am
Two foxes each session morning and afternoon.
Teams from Birmingham and Manchester
Lunch break and end of event QSY.
Contact [email protected]
Summary
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DF nights are great fun...even in the rain
Lots of opportunities for home construction
ARDF info http://www.oarc.org.uk/
C&D ARS are more than welcome to take part
We look forward to seeing you
• Goodnight and thanks for listening.