[SMCARA] Fort Washington Amateur Radio Club Fox Hunt - 30 May 2015

[Daniel Metcalf]

Forwarded on behalf of Kato Spears, President of the Ft. Washington
Amateur Radio Club.

Fort Washington Amateur Radio Club FoxHunt

When
Sat, May 30, 9am – 1pm
Where
100 Walter Thomas Road Indian Head, MD 20640 
Event
2M Radio Direction Finding “Foxhunt”
Saturday, 30 May 2015, 0900 – 1200 (Lunch at the Foxes Den from 1200 –
1300)
Sponsored by the Fort Washington Amateur Radio Club (FWARC)

Starting Point:
“Indian Head Pavilion on the Village Green” Parking Lot
100 Walter Thomas Road
Indian Head, MD 20640

Fox frequency: 147.555 MHz Simplex
The Foxes will be hiding in their den somewhere in Charles County, MD.
Foxes:
KB3SPH- the Reynard
KB3SWS- the Vixen
W3RL- the Tod

The Foxes will be monitoring TBD for check-in and in case anyone needs
to make contact.

Fox hunters:  If you plan to attend, please register now with Jeff
Humbert (KB3SPH) via email at humbertjs at comcast.net  or phone
301-848-8043 (leave message if no answer).  Also, please check-in on the
TBD repeater between 0830 and 0855 on 30 May 2015 to let us know you are
participating in the hunt.  Please give us your call sign and the number
of hunters in your party when you register/check-in.
Boy Scouts and Fox-hunting:

http://www.scouting.org/filestore/jota/pdf/TURNER.pdf

How to Build a Yagi antenna:

http://nt1k.com/blog/2012/vhf-3el-tape-measure-yagi/

 http://www.g6hoq.com/documents/2m%20tape%20measure%20yagi%
20instructions.pdf

http://www.open-circuit.co.uk/tape.php

https://sites.google.com/site/tapemeasureantenna/

Yagi Calculator (seen below)-
http://www.csgnetwork.com/antennae3ycalc.html


1.The event will be a mobile foxhunt starting from the Indian Head
Pavilion, 100 Walter Thomas Road Indian Head, MD 20640 at 0900 on 30 May
2015.

2.The Foxes will call every fifteen minutes on 147.555 MHz for two
minutes starting at 0900 (0900-0902, 0915-0917, 0930-0932, etc.) and
ending at 1200 or until all registered hunters arrive at the den. Clues
and hints to the Foxes’ den location will be provided at each 15 minute
announcement, becoming more descriptive with each announcement.  At
1130, 1145 and 1200, the Foxes will reveal where the den is for anyone
still on the hunt.  Lunch will be waiting for you when you arrive.
Please pass the word!

3. Participants should listen both on a rig with an omni directional
antenna to hear the fox (to confirm its up) and switch to a rig with a
directional antenna to narrow down which direction the fox is
transmitting from (based on signal strength and null and using the
process of elimination). 

4. The participant or partner (navigator) should draw a line on a map
from the start point (or their current location) in the direction where
they believe the fox is transmitting from. 

5.The team should get in their vehicle(s), move to another good
listening location (high ground and not on along that line drawn on the
map - rather perpendicular to it) and repeat until there are at least 3
lines drawn on the map which intersect. Where the lines intersect is
potentially where the fox is. 

6.The team should drive to the potential location and try to narrow it
down even further by repeating the process closer to the fox. You may
have to decrease the sensitivity of your receiver once you are closer to
the fox because it will seem like the transmissions are coming from all
directions. You can do this a few ways:

a. using an electrical attenuator connected between your radio and
antenna
b. slightly rolling off of the frequency (instead of listening to
147.555 try 147.550 or 560).
c. body shield your antenna 
d. take off your antenna completely or use a poor antenna
e. cover your antenna with aluminum foil on 3 sides 

7. Again, repeat the process of determining what direction the strongest
transmissions are coming from (or not coming from) and move to the area
where you think the fox is. 

8.There will be increasingly warmer clues as time goes by. 

9.Participants should bring a compass, map, protractor, ruler, pencil,
vehicle, VHF radio receiver, directional antenna, omni directional
antenna, GPS (to get you around safer).

Mytopo.com:

Fox-hunt Vids

https://www.youtube.com/watch?v=1U9Kz1mveQk

https://www.youtube.com/watch?v=k4DQIGz68tU

https://www.youtube.com/watch?v=i2RI-qkWf_A


Recap on Fox-hunting steps:

Meet at the Indian Head Pavilion, 100 Walter Thomas Road Indian Head, MD
20640 at 0900 on 30 May 2015
Meet and greet other hunters — team up and cross load if needed
Tune in xxx (TBD) MHz (Fox) 
Prepare directional antennas and compass and listen for the first clue
at (TBD)
Record most likely direction "fan" (strongest direction + and - 15
degrees)
Draw the fan or your map and stretch it as far as theoretically possible
Identify another suitable direction finding location and move to it
Listen on the 10s and repeat the direction finding process from two or
more locations
Identify where the fans intersect
Move to the suspected area and attenuate the signal to get a narrow fan
by:
​using a poor signal location
using a poor antenna
using an attenuator
using an off frequency
sheilding your antenna
using no antenna
Repeat the direction finding process until you find the fox!