EDCARC Logo El Dorado County Amateur Radio Club   AG6AU  ARRL Logo

Fox Hunt

Hunt Masters
Jeremiah K6JRN - Mark KJ6EUO - Greg KJ6GHL


Page Revised: 3/10/14

This Hunt is open to ANYONE.
If you plan on participating please send an e-mail to
Jeremiah with your name/partner's and call signs.


Teams:
1. 
2.
3. 
4.
5. 
6. 

Hunt Date: Saturday - March 29, 2014
Hunt Time: 9:00 am until 12:00 pm
Check-In: 8:30-9:00 am on club repeater  
Fox Transmission: Simplex 146.565   (AG6AU identifier and continuous on variable tone)
Announcements: Club Repeater 147.825 -pl 82.5
Start Location: Anywhere
Scoring: TIMED HUNT - First In.   Must identify location of transmitter.   
Boundaries: El Dorado County within a 10 mile radius of the intersection of US 50 and Ponderosa Rd/S. Shingle Rd.
Guidelines: *  This Fox Hunt is open to anyone and not only club members.
*  The highest scoring EDCARC member will be the one to sponsor the next Fox Hunt.
*  The fox transmitter will be at a location that does not require an admission or parking fee.  The location shall be in such a place that normal activities of the fox transmitter site would not violate the privacy of nearby residents and would not unnecessarily disrupt the operation of nearby businesses.
*   The antenna and transmitter shall be within 500 feet of standard passenger car access.   Reasonable care must be taken by the Fox to ensure that hunters on foot can safely reach the hidden fox transmitter.
*   The fox may use an antenna of any type and polarization as long as the antenna stays in a fixed location and single, fixed position throughout the hunt.   The signal power will remain constant throughout the hunt.
*   The use of outside assistance, such as getting bearings from operators at other locations is not permitted.   However, the use of GPS devices and laptop computers for determining location and for the plotting of bearings IS allowed.
*   The fox configuration is a radio, antenna, and power source hidden somewhere in the defined boundries.
Equipment  Suggestions: Compass, protractor, straight edge, maps, directional antenna and attenuator

Hunt History:

7/20/13

5/12/12  -  Mileage Based

Hunt Masters:  Dave W6DES / Tom N6GVZ / John W6YEA
Place    Miles    Team
1st        10         Jeremiah K6JRN / Kirby AF6OP
2nd       10.6      Jordan KJ6NHF and son Joel
3rd       10.9       Harry W6HFM / Ken K6KRD
4th        12.9      John N7HUE / Wyatt KJ6VTD / Floyd KD6MYQ
5th        14.6      Jay KE6GLA / Nancy KG6PNP / Natalie KJ6NLD
6th        19.0      Bob W1RH and wife Karen
7th        19.6      Bill W6LSW / Loretta N6NQH / Jerry K6GER / Donna K6DLR
8th        33.5      Jim K6LOY / Hal N6VIB
9th        35.9      Rick WA6NHC / Ken KJ6VEB and son Jonathan

10/22/11  -  Time Based
Hunt Masters:   Bob Hess W1RH and wife Karen
1st         Dave W6DES / Rich AD6AE / Tom N6GVZ
2nd        Rick WA6NHC
3rd        Bill W6LSW / Loretta N6NQH

8/13/11  -  Time Based
Hunt Masters:   Harry W6HFM / Ken K6KRD / Mel N6MCM
1st         Bob W1RH and wife Karen
2nd        Jordan KJ6NHF and son Joel
3rd        Frank W6DHN / Greg KJ6GHL


Transmitter Hunting: Radio Direction Finding Simplified    
Amazon used copies as low as $11.60

Transmitter Hunting Book This is a great book by Joe Moell K0OV.  It covers many aspects of direction finding and has details for hands-on projects.  Many hams have a well-worn copy of this book.  If you're into direction finding or T-Hunts, this is the reference / project / design / instruction book for you.

He has lots of practical information on his web site, "Homing In".  Especially worth reading are his articles "RDF Equipment Ideas for Radio-Orienteering"  Another place to look for ideas is the Direction Finding Equipment Reviews on eHam.net.

Tape Measure Beam
Less than $10.00 for parts



Optimized for radio direction finding, Joe Leggio WB2HOL presents his classic, detailed construction article about building two meter yagis out of steel tape measure material and PVC tubing.  These yagis are inexpensive, and rugged enough to handle wooded terrain.  Read the reviews at eHam.net for helpful construction tips.


Arrow FHL-VHF Loop Antenna
$59

Loop Antenna

Unlike some other directional antennas like a Yagi, the loop antenna is used in the null mode (minimum signal).  The null mode can provide a very sharp bearing, readable to plus or minus 5 degrees.

Arrow II Handheld Portable Yagi Antenna
$49

Portable Yagi Antenna



Cubical Quad Antenna Theory
 


4 Element Cubical Quad Plans 

Based on a design by K6OPS and K0OV modified by N6ZAV for 147 MHz vertical polarization.


Arrow Offset Attenuator 
$59

 

Ideal for the T-Hunt Loop and Arrow II Antennas.  This could very well be the best Offset Attenuator ever made.  It uses a 4 MHz. sine wave instead of a square wave used in most Offset Attenuators.  This reduces the interference from pagers and other radio services.  This offset attenuator can be used with any VHF transceiver or scanner radio that has a removable antenna.  The receiver must have sufficient frequency coverage to permit tuning it 4 MHz away from the hunt frequency.  An offset attenuator, sometimes called an active attenuator, is used in transmitter hunting to shift the receiver frequency 2 MHz or 4 MHz up or down from the transmitted frequency.  This solves the problem of the main frequency leakage into the receiver that essentially renders a standard attenuator useless when getting close to the transmitter.  It is good for getting close (within a foot) to perhaps a watt or two.  An RF attenuator is a device that goes between antenna and receiver to reduce the signal strength down to within the range that the receiver S-meter can handle.  Without one, you may think you're close to the fox transmitter when you're still far away.  You won't be able to get close enough to a camouflaged hidden T to identify it.  The amount of attenuation should be adjustable so that you can add just a little when your S-meter first pins, up to a lot as you get within a few feet.  Special ARDF receivers used by champion fox hunters have electronic attenuation built in, but ordinary handi-talkies don't.  Adding it would require major micro-surgery in the HT.


Mk 4 Sniffer Receiver
$295  Mk 4 Manual  Mk 4 Suggestions

Mk 4 Sniffer 

The most popular one-piece set among ARDF Team USA members is the frequency-synthesized Sniffer 4 from Bryan Ackerly VK3YNG in Australia.  It covers both the full two-meter band and the 120-123 MHz aircraft band with selectable AM, FM or audio S-meter tone output to the loudspeaker.  You can listen to both the receiver audio and S-meter tone at the same time with stereo earphones.  It includes automatic-ranging attenuation in 15 dB steps.  For multiple-frequency hunts, there are six programmable memories.  Sniffer 4 is lightweight and easily attached to the RGE VHF-144 antenna or a home-built measuring-tape beam.  A detailed product review by KØOV is in Homing In for Fall 2007 issue of CQ-VHF Magazine.  Sniffer4 is available directly from Bryan Ackerly in Australia and is also sold by Bob Miller Enterprises in California.  User Feedback  eHam.net reviews


PicCon Fox Transmitter Controller 
 Built & Tested with Case $66  PicCon Manual

Transmitter Controller  PicCon Case

PicCon is a small, inexpensive radio controller designed for hidden transmitter hunting.  When combined with a radio transmitter, it will produce tone sequences and Morse code messages at user-programmed times.  It is completely field programmable via DTMF tones, utilizes EEPROM for all programmed options so they are remembered when power is removed, and is quite compact.

PicCon interfaces to a radio transceiver like a packet radio TNC does.  It is controlled by the audio it receives from the radio, in the form of DTMF tones, and operates the radio by controlling the Push To Talk (PTT) while sending audio in the form of tones and modulated CW Morse code.

PicCon includes an LED, to show which state the device is in, and a push-button switch, to allow the starting and stopping of a transmission without requiring a DTMF receiver.  There is a jumper option on the board to activate PTT via the microphone line as is required by most hand-held radios.  PicCon draws only a few milliamps, and runs off any 7-35VDC source, including a standard 9-volt battery.

PicCon was created by Byron Garrabrant, N6BG.


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