Saturday, June 1, 2013

06/01/13-b - Direction Finding Exercise

Here is the Scenario sent to us by Dwayne N5XUL:

Direction Finding Exercise 1 June, 2013 Scenario

At approximately 6:30 AM this morning a level 5 tornado touched down in Collierville TN. This 

storm system spawned several tornadoes in the southeast. Collierville took a direct hit with 

several buildings in the downtown area being totally destroyed including the Mayor’s office and 

the cities Emergency Management office. All of the towns available emergency equipment and 

resources are over tasked. The Collierville Mayor has requested mutual aid from all surrounding 

communities and the state of Tennessee. Area hospitals have several patients that are being 

transported by all means available.

The governor’s office has activated the Tennessee guard to help the towns people.

Ham radio operators were requested to help out as well.

Your mission is to support local law enforcement and fire officials in this event.

There are several reports of people being trapped in their homes and businesses. 

You are requested to meet at the starting location for this event for your assignments. Please 

bring any equipment and supplies you may need to accomplish your mission.

This is a DF Exercise designed to get you thinking about an event happening in your area.

Please remember to be SAFE. You will be working as a team member for this exercise. There are

two teams for this exercise. One team will work the West side of the area and one team will work

the East side of the area. The center of town is covered in debris  and is closed down while crews

are removing electrical lines, trees and open gas main threats.

For this exercise both teams will go to two pre-picked waypoints using the Lat/Long coordinate 

system only.. These two points are simulated storm shelters that you are requested to check. They

are marked with small orange surveyors flags and a short piece of PVC pipe. Your job is to find 

these markers and bring them to me at the transmitter site. 

While at these locations use your DF equipment to take bearings to the transmitter location. I 

plan to use 147.420MHZ on an Arrow 3 element beam pointed at the start location. I also plan to 

use a normal non-directional antenna on 146.620MHZ. At the start of the exercise I will point the

arrow antenna directly at the start location for a  few cycles and then point it 45 degrees off and 

then 90 degrees off so you can see the differences. This will allow you to record the difference in

signal strengths and characteristics of a direction antenna.

To cut down on confusion and lighten my work load., each team will pick a team leader. 

Participants will give their information to their team leader and the two team leaders will send 

the groups best estimated bearing information to me over the Olive Branch repeater. Please 

remember that most Collierville repeaters are heavily damaged for the purposes of our exercise. I

will then relay actual Google Earth bearings and distance from your location to my location so 

you can compare information . This will give you direct feedback on your equipment and ability 

to take good bearings. 

We are breaking new ground with this exercise. Recent tornado events in Oklahoma have led me 

to my objectives for this exercise. They are as follows:

1. Be able to find Lat. Long. Coordinates using your own resources. This could be a GPS unit, 

computer mapping software, actual paper maps, Android or I phone applications. Please 

remember that an actual disaster could take down internet connectivity. 

2. Introduce participants to Direction Finding a beam antenna. The lessons learned from this 

exercise may be used in future exercises. I already have an idea in mind for the next exercise.

3. Introduce the concept of CERT teams and training. I have invited Collierville Cert instructors 

to attend our exercise. If you have not attended a CERT class, I highly recommend it. 

4. APRS concepts. Not all of our participants are APRS capable. If  you have an APRS radio, 

android, I phone application or Digital Radio for APRS, please bring it to the exercise. Please 

look at the symbols you can enter into your equipment. I would like you to set your symbol to 

“DF” and send a beacon from the start location as well as the Lat/Long coordinates I send you to.

After the exercise, all participants can go to and set it for the last 3 or 6 hours and 

see the actual  positions you were at for the exercise. This is a very helpful capability in times of 

disaster so almost anyone can see where you are/were at from around the world. I plan to beacon 

my transmitter location during the exercise so participants can view it on their equipment in the 

field. Word of caution: Do not use the EMERGENCY symbol over APRS unless you really 

want to  meet new people. It is taken very seriously.

5. Give participants an opportunity to use and test their equipments capability. Please bring a 

copy of your equipment manuals. There is nothing more frustrating then trying to program a 

function when you can’t remember how its done. Charge your batteries. Remember field day is 

coming up and this may give you an excuse to blow the dust off of your equipment early.

I am not going to pick the teams or team leaders for you on this exercise. I have done so on past 

exercises.  I want you guys to work this out on your own. I will recommend a few things you 

need to think about. Each team should have about the same number of people. 

Each team will need someone who has a mobile radio capable of hitting the Olive Branch 

repeater. Please program 147.255+, 79.7 PL tone. A 5/8 antenna on medium power should work 

well. I also want to thank Tim, KD5CKP and the Olive Branch repeater club for the use of the 

clubs repeater. I also hope some of their members will attend the exercise. Be prepared to 

program your radio to a different frequency just in case we need to change plans. Plan to use 

146.520 simplex to talk between groups to check your range of communications. The repeater 

will be primary.

Plan to have one APRS capable person in your group if possible.

I would pick someone who lives in the Collierville area for my team for obvious reasons. This is 

one of the reasons I picked Collierville. It gets most of us out of our comfort zone.


1. SAFETY: Yours safety in this exercise is the most important item. Watch your driving around 

Collierville. You are responsible for obeying all traffic laws. Don’t speed or drive in a reckless 

manner. Riders, GPS watchers and other participants, DON’T distract your drivers. Tell them

ahead of time they are approaching a turn or stop sign. Drivers Drive. Observers be safety

minded at all times.



Note the following definitions.

Definition: Fox hunt- participants may work together or as lone hunters to find  the fox

transmitter. Competition is often involved. First one there wins.




3. All “DF exercise participants” are welcome. If you want to attend a “Fox Hunt” this is 

“NOT THE EVENT FOR YOU”. We will have fox hunts in the future and you are welcome to

attend but the rules here are different. Please observe them. I do not want anyone to interrupt the

TRAINNING for those who wish to participate in the exercise.



In an actual event people who do not comply with the rules would be sent home. 

I do not wish to run anyone off with this comment but I work very hard to put together training 

exercises to teach new techniques to those who want to learn and test their capabilities and it is

very important that people follow the rules. This should be a fun event for those who participate

and I want your feedback and ideas for future events and scenarios that you would like to see. I 

do plan to have a debrief at the end of the exercise and I welcome your comments and critiques. 

If we have to reschedule this event, I will try to contact someone who can announce it on the 

Olive Branch repeater and the 146.82 repeater as well as e-mail so please monitor one of these 

repeaters on the way to the exercise. I will try to have it announced prior to the event if at all 

possible.  Thanks, Dwayne N5XUL

06/01/13 - Tri-State Repeater Assn. Meeting