|
| |
Transmitter Hunting
Equipment
|
|
| |
|
|
We currently have 115 hunters.
Each hunter will be asked to provide a list of equipment he or
she uses to t-hunt and will be given their own web page, listing their
personal favorites.
Please submit your list of T-Hunting equipment
to:
jim@thunt.org
|
|
March 11, 2005: The MK4
Sniffer is still my all time favorite, next to my Doppler
and Garmin GPS (StreetPilot 2610). |
|
Entry level (1st time hunting) equipment list.
1) Receiver, 2-Meter HT
(Handi-Talkie). Use your body to block the radio
signal.
2) Antenna adaptor or paper clip. When you get close,
remove the antenna and replace it with a paper clip or
the antenna adaptor to reduce the signal.
3) Map of the t-hunt area. So you can drive towards
the transmitter and not get lost.
4) HINT: Using your RECEIVER with the paper clip.
Place the radio on your dash and use it as a U-R-Here
radio. Your receiver will begin to hear the
transmitter when you are close...congratulation.
Little more serious equipment
list.
1) 3 to 6
element Yagi or 2 to 4 element Quad for the
2-Meter band.
2) Receiver, 2-Meter HT (Handi-Talkie).
3) Attenuator, to reduce the
radio signal so you can use your 'S-Meter' and locate
the strongest direction.
4) Magnetic Compass (Handheld).
5) Protractor and Grease
Pencil (Plot compass bearings).
6) Maps (Auto club maps of the area you are hunting).
7) Antenna adaptor or paper clip. When you get close,
remove the antenna and replace it with a paper clip or
the antenna adaptor to reduce the signal and body fade
the transmitter.
8) HINT: Use your RECEIVER and the paper clip. Place
the radio on your dash and use it as a U-R-Here radio.
Your receiver will begin to hear the transmitter when
you are close.
9) OPTION: Mount a mobile Radio in your car or just
use your RECEIVER with a mag-mount antenna. You can
use it as a distant U-R-Here radio. At S-1 your might
be as far away as 10-miles, at half scale S-5 your
getting closer maybe 4-miles and at full scale, you
better start listening to your RECEIVER with the PAPER
CLIP because, your really close now.
Equipment I use almost
all the time
1) Arrow-146-4-II Beam.
4-element 2-meter Yagi. I found the 4-element beam is best for
getting your initial
bearing. It has good gain (pulls in those really weak signals) and
has a narrow,
accurate, directional beam.
I use VK3YNG's MK4 Sniffer to receive the fox signal.
Smaller 3-Element setup for walking/running hunts.
2) Arrow
Attenuator. 0 to 75db of attenuation, necessary to
drop the signal strength of a Fox transmitter to tolerable
level. (Not necessary with the VK3YNG Sniffer MK4, it has
its own 9 built-in automatic attenuators).
I keep the Arrow Attenuator and Standard Radio for backup.
3)
VK3YNG Sniffer MK4. A 2-meter receiver with 9 built-in
attenuators (totaling 135db) and an audio signal strength
meter that increases in 'tone' as the signal gets
stronger.
a) Initial bearing receiver with my Arrow-146-4-II Yagi
(as long as the signal is strong enough).
b) U-R-Here receiver. Lets me know how close I'm
getting to the Fox (9-levles, from 6-miles to 1-inch).
c) Close-in sniffer with my Arrow-146-4-II beam (points
to the radiating Fox antenna within an inch).
Mounted U-R-Here receiver.
4) Compass.
Magnetic is best, I've tried digital and prefer a
non-battery operated compasses.
a) I've played around with a good digital compass again
but, have gone back to Magnetic.
A good compass, protractor and laminated map.
5) Protractor. The one's used by mariners to plot their
course. I purchased mine from West Marine.
6) Maps. One continuous map of the entire 'hunt' area
is very important.
'AAA' auto club maps seem to work best. Have your maps
laminated in plastic. You can write on them with a
felt-tip pen and erase the markings with Isopropyl
Alcohol.
a) I use the Garmin
StreetPilot-III GPS receiver with street-level
mapping for my map. It has the entire state of
California and Nevada on one memory chip. It can also
plot the shortest route to the fox (automatic street by
street directions). I tend to plot my initial bearing
out 5-miles and have the StreetPilot-III figure out the
shortest route to that point. It really helps when your
in a strange location and can't figure out how to get
there from here.
b) I've also been using a laptop computer
running Topo-USA for my maps. It works great because
it covers the entire western United States. Topo-USA
also allows me to plot and save all my bearings, as well
as see the terrain (such as mountains) that may cause
radio signals to bounce or become obstructed.
7) AHHA Microfinder
Doppler. Great for getting to the
fox without stopping for more bearing. If your serious
about transmitter hunting, this device will make hunting
FUN and easy.
Mobile radio, GPS and Doppler.
Doppler antenna. 8) Mobile amateur radio.
Standard C5900DA Tri-band. Your radio doesn't have to be
the C500DA, any mobile radio will do, as long as you can
scan or receive all the FOX channels and the talk-in
frequency. I use my mobile radio as a distant U-R-Here
radio. At S-1 I am probably 10-miles away, at half scale
S-5 I'm around 4-miles and at full scale I am only 1-mile
away. At this point it is a good idea to have a U-R-Here
radio, I use the Sniffer MK4. It takes over the duties
where the mobile radio leaves off. The MK4 will progress
from attenuation #2 (1.5-miles) to #7 (30-feet) away from
the transmitter.
2.2 MB C5900DA Owners
Manual in PDF format.
Useful.
9) Backup 2-meter HT (Handi Talkie). In case the Sniffer
MK4 can't hear the Fox for the initial bearing.
10) Arrow Fox
Hunt Loop Antenna. Very directional and very wide
receive range (although it is a little deaf).
a) When ever possible I will use this antenna,
primarily because it is less affected by reflections (due
to its Faraday shield) and the null provides a very sharp
bearing (much sharper than a beam).
b) Also, because it is small (6"). I will use it when
the Fox hides in a Shopping Mall or some other tight
quartered environment. 11) Flashlight. Most hunts end in the dark.
a) I use the SureFire
E1e/KL1. Only 3.3 inches long and weighing 2.2 ounces,
this little LED flashlight put out more light than a
2-D Cell Flashlight. I can clip it onto my baseball
cap and also use it as a hands free head-band light.
|
|
|
| |
|
 |
Arrow 146-4-II (manufacture),
a 4-element two-meter Yagi.
The four element beam is your
best bet for an initial bearing. You can pull out weak signals
(sometimes they are very weak) and the directional lobe is
narrow, giving you the confidence that you are headed in the
right direction.
HINT: Turn up the attenuator and your squelch, until
your receiver only receives the fox for a short 'blip' while you
swing the beam. This will give you the most accurate direction.
Using the Icom R3 in DF mode
displays a GRAPHIC of your signal strength and using the
Sniffer MK4 is even easier. It
has an audio signal strength circuit that increases in Tone as the
signal gets stronger and also has 9-built-in (automatic stepping)
attenuator.
|
 |
Arrow 146-3-II
(manufacture),
a 3-element two meter yagi. Very useful and portable. Although I
don't use it much anymore, I like the Arrow 146-4-II 4-element
beam much better. I thinks it's because most of the competition
uses 3-elements and the 4-elements gives me a slight edge on
hearing a weak transmitter and pointing at it a little more
accurately. |
 |
Arrow
Satellite Beam (manufacture). 3-element 2-meter and 7-element 70cm.
I have found this duel band beam to be the most versatile
transmitter hunting beam I have owned. The three element 2-meter
portion is a compromise. I personally like to use four elements
for my initial bearing because of the extra sensitivity however,
the three elements on 2-meters makes it a lot more compact and
easier to maneuver when walking.
The 7-element 70cm portion really won me over.
Using a truly duel band transceiver (Standard C568A), I leave
the left VFO on the fox frequency and the right VFO on the third
harmonic. I can hear a 50mw transmitter clear across a large
park on the VHF side and then sniff out the fox, within a few
feet on the UHF side without changing radio's or beams. I still
have to use my Scout-40 (frequency counter) and
attenuator for an even closer, pin point location (under one
inch).
|
 |
Attenuator
(manufacture). This resistor filled
switch box is essential in cutting down a strong signal strength getting
into your receiver. It allows you to read your S-Meter at half scale for
the strongest signal in a given direction. (Attenuation level 0 - 75db).
Pretty cheap and works really well.
Do not transmit through any ATTENUATOR. Disable the PTT. |
VK3YNG
Sniffer MK4
more details
 |
VK3YNG Sniffer MK4
(manufacture). This receiver, made by
VK3YNG, is
designed for quickly finding the direction of beacons or
hidden transmitters. Anything from distant weak signals
to very close "sniffing" of transmitters running many
watts of output power can be pin pointed accurately
without suffering "overload" problems that plague other
designs. Full auto-ranging operation allows the operator
to quickly and intuitively locate the source of a signal
without twiddling knobs or watching meters. The operator
is freed to concentrate on more important things such as
negotiating terrain or reading maps.
Frequency Coverage: 120-122.995MHz,
143-149.995MHz. in 5 KHz steps.
Receive Modes: AM, FM and Signal
strength TONE. Sensitivity seems to be .1uv
I use the IRON HORSE Mini-Mount Antenna,
mag-mounted on the hood of my car and connected to the
MH4 Sniffer. This gives me a very stable and consistent,
mobile, U-R-Here radio.
I really like this antenna. Very easily
transported and used. |
 |
Compass
(West Marine).
I have found a good magnetic compass, like the
one pictured, is a must. I own and have used many digital,
electronic, compass's and found the batteries dead or needed
recalibration when I needed it. Make sure your compass is liquid
filled. |
 |
Protractor
(West Marine).
A good plotting protractor is also a important. Plotting your
initial bearing on a large map of the hunt area must be accurate
and fast. |
 |
The
Garmin
StreetPilot (satellite, global positioning system), during the hunt,
helps me predict my course of action and and avoid dead-end streets. I now use the Garmin
StreetPilot-III
manufacture,
for auto-routing the shortest distance between two points on street level maps.
It really helps when your in a strange
location and can't figure out how to get there from here. Also,
when hunting in the mountains, I use "plot fastest route" instead
of "shortest distance". I have found some of the roads listed on
my maps are impassable or private. When plotting "fastest route",
the StreetPilot-III almost always plots a drivable route.
|
 |
Garmin
StreetPilot-2610.
Just choose your destination using StreetPilot’s touch screen or
remote control to be automatically guided with turn-by-turn
directions and voice prompts. Both the
2610 and
2650 feature color displays, built-in maps, and everything
needed to download additional map detail and look up points of
interest and addresses in seconds. Select maps and transfer data
directly to the unit through a USB connection and onto a standard
CompactFlash® memory card. These products are powered using the
external speaker with 12/24-volt adapter cable or A/C power
adapter (both are included in the purchase).
|
| |
Laptop. I
like using Delorme TOPO-USA for my maps. It covers the entire
western United States and also allows me to plot and save all my
bearings. TOPO lets me see the terrain (such as mountains) that my
cause radio signals to bounce or become obstructed.
I installed the "Gamber
Johnson" laptop mounting hardware to my
1998
Jeep Cherokee without drilling holes. It mounts to the
passenger seat rail bolts. Gamber Johnson has mounts for almost
all vehicles (Gamber
Johnson product search). |
  
 |
Using a Doppler like the "AHHA
MicroFinder manufacture" improved my transmitter hunting and made hunting a lot
more fun. Watching the display pointing along my initial bearing is a big
help in building confidence. The Doppler really shines when you are
close-in, giving you the edge when winding around short City streets,
trying to home-in on the Fox. The "AHHA
MicroFinder manufacture" can display your
desired direction in three modes, raw non-filtered and two
digitally filtered modes. Filter-1 can reduce the flutter of a
general direction by 30% (not user adjustable). Filter-2 can
reduce the flutter to a single LED (user adjustable).
Operational Parameters for Filter-2.
QQ/MISS/DEPTH.
QQ: indicates the required good signal quality before a sample
signal can be placed in the queue. (0-9)
MISS: indicates how many signal samples may be missed
before the queue is emptied and has to start acquiring samples
again.
DEPTH: indicates how many good samples must be in the queue before
a signal is considered "acquired" and is displayed. (1-100)
Factory default was set to display a
direction, if it can acquired 12 good signal samples with a signal
'Quality' of 2 or better but, will throw out all the good samples
and start the acquiring process all over again if it receives 10
bad signals at anytime. This setting was
too accurate. It only started to point when your really close to
the Fox. Experimenting with the
Parameters of Filter-2 has lead me to leave the 'QUALITY' set to
'2', the 'MISS' parameter to 10 but, reduced the 'DEPTH' to 10
(2 / 10 / 10).
I have to tell you, this 'Digital Signal Filter" really worked.
No more ambiguous, multiple, spinning LED's pointing somewhat in the
direction of the Fox. What I saw was only one LED pointing in the
direction of the Fox. When acquisition of the signal was lost, the
Doppler continued to point in the last known direction of the
transmitter. If you pass through a 'Hot' spot of good signals, the
Doppler locked onto and only displayed the direction of the good signal.
I haven't noticed any loss of accuracy. However, I did notice my Doppler
displaying a very regular and consistent direction to a hidden
transmitter.
I'm going to play around with other setting like,
QUALITY 4, MISS 5 and DEPTH 5. Maybe QUALITY 2, MISS 7 and DEPTH 7. How
about QUALITY 1, MISS 10, DEPTH 20 ?
I changed the Doppler's 'Filter'
parameter on the Feb.2,2002 hunt to
Quality 2, Miss 9 and Depth 9 (2 / 9 / 9). This seems to be the
lowest (least accurate) I want to go. The Doppler seems to be very
responsive with this setting, giving me reasonable accuracy in pointing
to the transmitter. The jammer transmitter gave me a little trouble only
because the Fox chose to transmit short (2 to 3 seconds) bursts at 5
minute intervals. Waiting for the transmissions, I was stationary. When
I started rolling to average the signal through the filter, the
transmission stopped. I would recommend using the Doppler in non-filter
mode on jammer hunts like this.
Like on the Feb. 2, 2002 hunt, I left my QFIL set to (2 /
9 / 9). On this hunt, Feb 16, 2002,
the setting worked out perfectly. I'm leaving it set to the almost
perfect (QFIL 2 / 9 / 9). The
AHHA Doppler pointed most of
the time and correctly to the Foxes. I only noticed a few incorrect
directions and only for an instant. The Doppler corrected itself very
quickly. I think we have have winner here.
By the way, I have version 1 of the
AHHA MicroFinder. Version 2
has even more features.
|
Standard C5900DA (discontinued)
Yaesu FT-8900R (Replacement) |
Mobile
Radio
Standard C5900DA Tri-band. Your radio doesn't have to be
the C5900DA, any mobile radio will do, such as the new
Yaesu FT-8900R, as long as you can scan
(receive)
all the FOX channels and the talk-in frequency quickly. I use my mobile radio as
my initial U-R-Here radio. At S-1 I am probably 10-miles away, at half scale
S-5 I'm around 4-miles and at full scale I am only 1-mile away. At this
point it is a good idea to have a better U-R-Here radio, I use the Sniffer MK4.
It takes over the duties where the mobile radio leaves off. The MK4 will
progress from attenuation #2 (1.5-miles) to #7 (30-feet) away from the
transmitter. Due to a large demand on copies
of my C5900DA owners manual, I have made an Adobe Acrobat - PDF
file of the C5900DA Owners Manual. Click:
2.2 MB PDF FILE. |
Kenwood TH-F6A |
Kenwood
TH-F6A
Tri-Band Hand-Held Transceiver
2m, 220MHz & 70cm
I've settled on using this little radio as my EDC (every day
carry) radio and it works great for communications during a
transmitter hunt. It can receive 2 frequencies simultaneously,
even on the same band, I can listen to the FOX and Talk-In
channel.
PDF manual for the TH-F6A |
 |
Arrow Fox Hunt Loop Antenna
manufacture.
The loop works backwards from a Yagi. Instead of looking for the
strongest signal, with the loop you look for a null (lowest
signal). The Loop Antenna has the advantage of being less affected
by reflection signals (due to its Faraday shield) and the
null can provide a very sharp bearing (readable to plus or minus 5
degrees). Another advantage of this antenna is it is small (6")
and light (1.7oz). The disadvantage is it has two nulls 180* apart
and can't hear weak RF signals.
Because the Fox Hunt Loop Antenna is
not a tuned antenna, it may be -10db down from a unity gain 1/4
wave spike (I found it to be a little more than -15db down). On the bright side, since the loop antenna is not
tuned, it may also have a very large frequency spread. Well just
have to see how wide it is (I tried it and it can DF at least down
to 740KHz and as well as our local 442MHz repeater, my wireless headset at 912MHz
was iffy). I wonder how it compares to a rubber
duck antenna commonly supplied with our handi-talkies. Since
rubber duck antennas are known to be deaf and 80% of the time we
can hear the Fox with our rubber duck antennas, I would think the
Fox Hunt Loop Antenna could be used at the start point quite
frequently.
Conclusion (John Kemper, FAA Agent): "The Arrow
Antenna New aluminum FHL loop was equal to or superior to all
(three) other loops tested, in all conditions".
Hint: Depending on the shielding of
some plastic radios, more than about 15db of inline attenuation may cause a
loss of the null. Tuning your radio 5 - 10 KHz. off frequency may
work as an attenuator. |
E1e/KL1
E2e and E1e/KL1 |
SureFire (manufacture)
E1e-HA Flashlight with KL1 LED
Bezel.
Power Output - 16 to 17 Lumens.
Battery Run Time - 1-1/2 Hrs. Full bright, 10 Hrs. Moderate light.
Battery Type - (1) Lithium SF123A. $1.25ea. at
SureFire.
Length - 3.3 inches.
Weight - 2.2 ounces.
Diameter - 0.8 inch Body.The E1e/KL1 is
brighter than a 2-D Cell flashlight and much smaller. I can carry
this flashlight everyday and also clip it onto my baseball cap as
a hands free head-band light.
I also bought the
SureFire E2e which comes
with a 60 Lumens Xenon bezel. This is about as bright as an 8-D
Cell flashlight. I can screw on the KL1 LED bezel and get 17
Lumens for about 4-1/2 hours on (2) Lithium SF123A batteries.
Length - 4.6 inches.
Weight - 3.2 ounces.
|
  |
Super
DF.
TDOA (time difference of arrival).
This direction finding tool is
the single most versatile of all the equipment mentioned.
With this one tool, you can;
1) Obtain your initial bearing from the start point.
2) Hunt Vertical or Horizontal signals by rotating the antenna.
3) Hunt while mobile with the antenna mounted
outside the car.
4) Hunt Close-In, within a foot of the fox transmitter.
Reflections are this tools
single biggest problem.
1) Incomplete nulling of the RDF tone, you have multi-path.
2) Harsh or raspy RDF tone, you have multi-path.
3) Incorrect bearings, reflections.
Reduce the error caused by multi-path.
1) Take several bearings close together, about 1 foot apart.
2) Note the two most extreme (divergent) bearings.
3) The best bearing is the middle of the two extremes. |
| |
|
EQUIPMENT USED FOR BACKUP
|
Click for more details |
Icom IC-R3
manufacture. (Backup Receiver).
This Icom receiver comes with a
Direction Finding mode. I have found this
function very helpful. Since the display graphs signal strength, you can
quickly determine the direction of peak signal meter readings. Body-fading
is now so easy. You can use the R3
as a U-R-Here radio too. With four built-in attenuation levels, I am
able to step my distance to the fox, from two miles away, down to 250
feet from the transmitter. Any other U-R-Here radio only gives you one
indication and that is usually 1/2 mile.
Click here for my report and
conclusions. The
receiver for your
initial bearing beam must be sensitive and have excellent
selectivity. I have used a LOT of radios and found that "STANDARD
RADIO handhelds" have the best immunity to adjacent channel and
frequency mixing interference however, Standard is no longer in
business. The Icom IC-R3 is acceptable for your initial bearing
and is an excellent U-R-Here radio. |
 |
Close-In,
Scout-40manufacture Frequency
Counter.
Using a Frequency Counter (the Scout-40 has a signal
strength meter), with your initial bearing beam and attenuator, you can
sniff out the radiating element of a fox transmitter to within less than one
inch.
The Scout-40 has a maximum range of
about 500 feet (typically 250 feet). If you use the Icom-R3 will
your beam, you can get you within 250 feet of the fox before it
saturates. Switch to the Scout-40 with your beam and sniff out
the fox to within less than one inch. |
| |
|
USEFUL
TOOLS I NO LONGER USE
|
 |
U-R-Here, 1st 'IF' (your close) Radio
Next, I setup my U-R-Here radio, a
Yaesu
VX-1. I set this radio
to a frequency that is double the 1st 'IF' and then add it to the fox
frequency. This give me a radio that is relatively insensitive and can get to
within 1.5 miles of the fox before sounding off. The U-R-Here radio will
become full scale at about a 1/2 mile from the fox.
|
 |
Close-In,
70cm beam, 3rd
Harmonic
Once your within walking distance of the fox, you
still have to find it. I use this small 70cm beam and attenuator setup,
tuned to the third harmonic of the fox transmitter. As long as the fox emanates
harmonics and your within 1,000 feet, this setup works great. I can get
within a few feet of the fox. |
 |
Using the Xplorer Test Receiver.
This expensive test receiver fills some gaps left
open by the 70cm beam and 2-meter/frequency counter setup. However, I
don't think its worth the expense or setup inconvenience. The range
on this device, connected to the 2-meter beam is around 1/4 mile and can
get within about 30 feet of the transmitter before it saturates the
receiver. |
 |
Flashlight
manufacture. Most hunts
end in the dark. You must see where your going, your equipment
and the hidden transmitter. I use C-Crain's 3-LED
'PETZL' head-band light. A hands-free light is very useful. |
| |
|
|
|
|
Some interesting bits of information &
Equipment
|
|
Doppler
MicroFinder Doppler Control Unit |
Vehicle Setup
Doppler setup in my 1998 Jeep Cherokee |
Jeep Cherokee
Doppler Vehicle, 1998 Jeep Cherokee Classic |
|
|
|
|
|
PicCon Controller |
My latest fox box. PicCon Controller, Standard C558A,
2-GelCel Batteries
and cooling fan. |
Iron Horse, Mini-Mag-Mount Antenna.
This antenna works as well as the famous 'J'-Pole for the fox
transmitter and it's easier to set up.
|
|
|
|
Fox Box
Fox transmitter & Controller in an old ammo box.
This transmitter can be programmed and turned
on remotely. It can also be used as a cross band repeater. |
Transmitter
Controller, battery, cooling fan and transmitter.
Ready to be programmed and turned on.
Continuous operation at 5-watts for 7 hours. |
|
|
|
|
|
Fox Controller KIT