Product Review: Polk’s Hobby Tracker III RC System - 2006/01

56 MODEL AVIATION
Product Review: Polk’s Hobby Tracker III RC System
BOB ABERLE
THE TRACKER III transmitter is a “nextgeneration”
product. The original Tracker
dates back to the early 1990s, but I obtained
my Tracker II transmitter and companion
Seeker II receiver just two years ago. It is
currently my primary operating system, and
I’ll tell you why!
Polk’s Hobby has been involved with
synthesized RC systems for almost 15 years.
It has pursued what many of us consider the
better approach.
The Tracker transmitter can broadcast
signals on all 50 of our aircraft RC channels
throughout the 72-73 MHz band. A built-in
scanning receiver (inside the transmitter)
listens to make sure the channel is clear
before allowing it to go “on the air.”
The Seeker II or Seeker 6 receivers can set
themselves to the transmitter channel, making
it easy to find an open or clear channel
anytime you want to fly. That’s what the
Tracker and Seeker do well. But I want to tell
you why I think Polk’s Hobby does it a better
way.
Synthesizers are not new to our hobby. I
flew the Kraft Channel Master system more
than 20 years ago. As do many of the presentday
synthesized RC systems, the transmitter
had essentially an adjustable frequency
module. It contained two tiny rotary dials. If
you wanted to operate on channel 42, you
dialed a “4” and a “2” and you were set.
However, those dials were (and still are in
many cases) located on the inside of the
module. That being the case, you had to
remove the module (unplug it), rotate the
dials, and plug it back in. Once you did that, it
was no longer obvious what channel you
were on since you could no longer see the two
dials. Many of us found that repeatedly
plugging in and unplugging the radio-
A close look at Polk’s Hobby Tracker III RC synthesized transmitter. Besides the
frequency, it can also store individual programs for up to 99 models.
L: eight-channel-function Seeker II receiver. R: six-channel Seeker 6—ideal for small
models. “Set” button, plugged into both receivers, is used to set frequency to match
transmitter.
Tracker III system includes transmitter
and (L-R) switch harness, single servo,
four-cell Ni-Cd receiver battery pack, and
dual-output battery charger. Your choice
of Seeker receiver is also included.
January 2006 57
The two LEDs indicate power and RF output. Red indicates that
the transmitter is not broadcasting a signal. Green indicates that
the transmitter is “on-the-air.”
The “C” switch is typically assigned to elevator dual rate control;
the “D” switch can be used for rudder dual rate. Rotary knob is
for CH 7 auxiliary control. At top right corner is three-position
switch for CH 8 auxiliary function.
Rotary knob is CH 6 auxiliary control. The “A” switch has been
assigned to aileron dual rate or expo rate control. At right is new
momentary contact trainer switch. At top left is another threeposition
switch for CH 5 function.
Heart of the Tracker III computer system requires the use of six
control input buttons. The instruction manual explains their
function; it is easy to learn.
Dual output charger can charge transmitter’s eight-cell Ni-Cd
battery pack and four-cell receiver battery pack. This is a C/10, or
“overnight,” charger.
Photos courtesy the author
• Built-in scanning receiver checks the entire 72-73 MHz RC
band before allowing the signal to go “on the air.” Eliminates
the chance of causing local interference at the flying field.
• Ninety-nine memory positions capable of operating any FM RC
receiver on the market.
• Synthesized to operate, at your selection, any of the 50 RC
aircraft channels.
• Channel selection can be stored in the memory positions and
does not require removing a module and rotating any dials.
• Models can be named to show up on the LCD display for
identification purposes.
• Companion Seeker synthesized receiver can be “tuned” to the
Tracker frequency without being removed from the aircraft.
Pluses and Minuses
+
-• Memory positions 11-99 need to be initialized.
58 MODEL AVIATION
No frequency flag comes with the system. Bob created his own
from white plastic sheet material. He writes the channel number
in use on the tag with an erasable marking pen.
Bob keeps a list of all memory positions in use, their frequency,
and aircraft names on the back of his channel marker.
First display appearing each time you turn the power switch on
shows operating channel and current operating frequency. Present
operating voltage is at lower right.
In Track 1 menu you do such things as assign memory positions,
channel number, and aircraft name. In this screen the channel of
operation was set to 36, which is 72.510 MHz.
The model-memory position can be named with as many as eight
characters. The [#01] indicates model memory selected.
To set up and store data above memory position 10, you must
copy a basic set from a lower memory number. Number 1
memory is being copied to set up new memory 11 position.
Typical data point in Track 2 menu system is important Trim
Memory that lets you store trim positions for a particular model
in memory. Following the procedure, all trim levers can physically
be put back to center.
After making any control adjustments in Track 1 and 2 menus,
you must do a “DATA SAVE” before turning power off.
Otherwise changes will be lost.
frequency (RF) modules eventually wore out
the connector pins.
If you have a transmitter with six or seven
model programs, you may be using several,
as many as six or seven, different RC
channels. In the course of one day at the field
and having several models with you, you
might be pulling and resetting that
synthesized module many times.
How does Polk’s Hobby address this
problem? It has resorted to a pure electronic
(solid-state) approach. There are no dials to
rotate; it is all done much as it would be on a
computer.
When you are first setting up a new
Screwdriver points to new trainer-cable jack. The cable must be
purchased separately and will allow you to connect to a second
transmitter for instructional purposes.
aircraft, hold down the “UP” mode button
while turning on the power. That will bring up
the Track 1 menu, which you use for basic
setup or when changing from one model
memory to another. For safety’s sake, when in
the Track 1 menu you are not broadcasting a
signal and therefore can’t possibly interfere
with anyone else at your flying field.
Select a new memory spot (1-99), then
select a channel that is the same frequency as
your receiver. You do this by pressing the
“INC” or “DEC” button on the front of the
transmitter. Keep pressing until the channel
number and frequency appear on the LCD
screen.
Finally, use the mode button to scroll to
“Model Data Save,” and then press the
“DATA [+]” button. You have now saved that
particular channel in that specific memory
position. You can also name your model for
future use, but I’ll get into that later.
When at the flying field, all you need to do
to go from one model memory to another is
call up the Track 1 menu and select your
memory position for that aircraft. It will
always be on the correct channel (operating
frequency), and you don’t have to rotate any
dials or remove a module. The Tracker III
transmitter has 99 memory positions, so it can
handle a load of airplanes!
Another important feature is the built-in
scanning receiver. Every time you turn on the
transmitter power switch, the scanning
receiver checks your intended operating
frequency to see if it is clear. It will tell you to
wait, and then it will tell you it’s okay to fly.
If someone is already on that particular
channel, the receiver will not let you
broadcast a signal until that person turns off.
This scanning receiver is so sensitive that
we’ve found it possible to detect third-order
intermodulation (3IM) interference at the
local flying field.
The effects of 3IM happen when two
transmitters operating on precisely the right
combination of frequencies produce
interference on a third signal. That third
frequency can, in many cases, be picked up by
the scanner.
If we get a “wait” message at our field, we
generally call out, “Who’s on channel so-andso?”
If the pilots who are flying yell out
different channels, you can be sure 3IM is
causing the problem and you best wait until
one of them turns off. This is an excellent
safety feature and the reason why my local
club recommends the use of this particular
transmitter.
Still another neat feature is the two
synthesized receivers that Polk’s Hobby
offers: the Seeker II (eight channel) and the
Seeker 6 (six channel, small, and weighing
0.54 ounce). These receivers are not exactly
new, but they are great complements to the
Tracker transmitter.
The eight-channel receiver is a larger unit
that will be more comfortable in larger and
heavier models—especially those that require
as many as eight different channel functions.
The newer Seeker 6 is an excellent choice for
small aircraft such as park flyers and backyard
flyers.
Again, the advantage Polk’s Hobby
provides is that no dials have to be rotated to
obtain a new channel or frequency. Actually,
tuning one of these receivers to the
synthesized Tracker transmitter is a snap.
Set your Tracker to a channel that is not in
use at your flying field. Fully extend the
antenna. Bring that transmitter antenna in
close proximity to the Seeker receiver antenna
so that they are almost touching.
There is a “SET” button that exits the
receiver on a short cable. You can locate this
switch so that it is accessible from the outside
of the aircraft fuselage. Hold down that
“SET” button while you turn on the receiver
power. The servo plugged into the numberone
position will pulse back and forth. It will
do that for approximately five seconds and
then the servo will stop.
At that instance the Seeker receiver is
locked onto the Tracker transmitter’s current
operating frequency. The receiver will keep
that frequency locked in, even when the
power is turned off. It will not change until
you physically change it. The beauty of this is
that you don’t have to dive into your fuselage,
remove the receiver, and rotate a couple dials
to change the channel.
The Tracker transmitter will operate any
FM (Pulse Position Modulation, or PPM)
receiver on 72 MHz. You can even select high
or low FM deviationAirtronics and JR receivers, which are on
high deviation (positive shift), and FMA
Direct, Futaba, Hitec, and Ace receivers,
which are on low deviation (negative shift).
Likewise, the Seeker receivers will work with
any other FM (PPM) transmitter since they
automatically detect deviation.
How does Polk’s Hobby market its
Tracker III transmitter and the Seeker
receivers? For the US market the company
offers systems on the 72 MHz aircraft
channels and 75 MHz for the surface-vehicle
market.
An eight-channel Tracker III transmitter
with a Seeker 6 receiver, dual-output charger,
four-cell Ni-Cd receiver battery pack, a
Polk’s servo (item PLK12003), and a
miniswitch currently sells for $180. The
rationale for offering a single servo is that
most modelers have their own preferences,
and there is no point in supplying four servos
that might never be used. Polk’s supplies one
to let you get accustomed to the system
operation.
The system I just described but with an
eight-channel Seeker II receiver is $200.
There are other combinations, as well as
systems on 35 and 40 MHz for the European
market. You can check out these options on
Polk’s Hobby’s Web site.
Tracker III Details: Now that you are
familiar with the Tracker and Seeker
components, I’ll explain what is different
with the new Tracker III transmitter. You
will notice a newly designed and stylish
case with more rounded corners and a
definitely cleaner appearance. This case is
much more comfortable to hold, and I’m
in favor of that. Without all those fancy
facets, nooks, and crannies, the case is
much easier to keep clean too.
A provision has been added for a trainer
cable that will allow you to tie in two
transmitters for training purposes. A jack is
provided for the cable, and there is a
momentary contact switch (designated “TR”)
to allow the instructor to take control when
the student gets into trouble. The trainer cable
must be purchased separately.
That trainer jack is also compatible with a
simulator cable that is available as an option.
It will allow you to use your Tracker
transmitter as a control input box to operate
simulator software installed or downloaded to
your PC.
Another nice feature is the ability to name
your model, with up to eight characters (using
alpha, numeric, and certain symbols), for
each model-memory position and have that
name appear on the LCD screen every time
you turn on the power.
However, I must point out that the modelmemory
position number (1-99) no longer
appears on the LCD screen. I was
disappointed at first, but I came up with an
interesting situation.
I was using memory position 12 and set
my operating frequency to CH 12. When I
turned the transmitter on I ended up with 12
and 12, and it looked kind of confusing. So in
retrospect I think having the eight-character
naming is just fine.
One thing you lose on the Tracker III is
the RF output meter. In its place are red and
green LEDs. The red light glows when the
signal is not on the air or when the battery is
too low to operate. The green lights up when
a normal signal is being broadcast.
The digital readout of the transmitter
voltage still appears on the LCD screen when
in the normal operating display mode (every
time the power is turned on). There is a lowvoltage-
warning alarm, but it wasn’t
mentioned in the first edition of the
62 MODEL AVIATION
instruction manual. Rest assured that it will be
added quickly.
Some of the auxiliary switches are in
different locations than they were on the
Tracker II. At the two top corners of the case
there are still two switches (left for CH 5 and
right for CH 8). Both of those are now of the
three-position variety (they were formerly
two-position switches).
If you use one of these switches for the
retract function, you will have to remember to
go from one extreme to the other. The CH 8
three-position switch will be ideal for threeposition
flap settings. There are no labels on
these two switches, so it may be necessary to
add your own if you feel you need them.
There are three switches on the front
panel, designated “A,” “C,” and “D.” These
are typically for turning on and off dual rate
control and exponential (expo) rate control.
You can actually assign all the switches to
positions of your choice; this is done in the
Track 2 menu.
I set switch “A” for aileron dual rate/expo,
switch “C” for elevator, and switch “D” for
rudder. That leaves two more channel
functions (5 and 6) that can be operated by
rotating knobs. When you compare the
Tracker III and II, you will see that some of
these switches are in different locations; this
might get confusing if you are flying both
transmitters.
I won’t supply a specification box with
this review because Polk’s Hobby was
kind enough to place the entire Tracker III
operations manual and all the necessary
specifications in a PDF file on its Web site
at www.polkshobby.com/pdf/tracker3
manual.pdf.
Keep in mind that you get dual rate
control and expo rate control on three channel
functions: ailerons, elevator, and rudder.
Servo reversing and endpoint adjustment are
available on all channels.
All four primary channel functions have
trim levers—not digital buttons (which I
don’t favor!). It’s the old fashioned way; the
trim lever’s position indicates roughly the
amount of trim and in what direction.
You still have the all-important Trim
Memory function that lets you save the trims
for each model and then return the trim levers
to their neutral (center) position. You can tell
when the trim lever is centered because a
“beep” will sound.
As does the Tracker II, this new model
requires that you manually “SAVE” after
having made control-input changes, prior to
turning off the transmitter’s power. This
might prove to be confusing to some RC
fliers who own computer-type transmitters
that save the command inputs automatically
when the power is turned off.
When you get down to it, the nice thing
about the Tracker III is that it will
probably be the only transmitter you use
(since it can operate any brand of receiver
on any of the 50 RC channels). That being
the case, you will become totally familiar
with its functions and never be confused
because you won’t be going fromappropriate to note that programming the 99
memory positions requires a slightly different
technique on the Tracker III. The first 10
positions are “business as usual”; you just set
your model name, frequency, and all your
control inputs into each position.
However, Polk’s did not program all the
data into positions 11-99 because it takes so
much of the service technician’s time. The
manual instructs you on how to cope with this
problem.
Primarily, what has actually happened is
that the data for the travel volumes, trim rates,
and dual rates are set at zero. This is the initial
root program setting. None of the channels
will work until the values are raised above
0%. Model programs 1-10 already have these
functions set to 100%.
One clue that the model program hasn’t
been initialized is that you will see odd
characters (I call them dingbats) where the
model name would go. You’ll find these
characters again in other parts of the Track 1
and 2 menus that will indicate that this feature
has been inhibited and needs to be set. If you
fail to change the data, it will seem as though
your receiver isn’t responding, naturally
because the control functions have no value.
Bringing the program up to date, as it is in
model memory positions 1-10, isn’t hard, but
it is tedious and time consuming. You just
move through the program features as you
normally would and use the command buttons
to bring the values up on every channel.
The easiest way I found to avoid
programming every model is to set up
memory 1 as a typical aircraft and assign the
switches that will be most commonly used.
Then each time I go to set up a new model, all
I have to do is copy memory 1 into the new
position. I might copy 1 to 14, or 67 for that
matter. Then I can name the new position and
set the operating frequency and all the
controls peculiar to that new model.
I found that when trying to get into the
Track 2 menu to adjust the various controls, I
couldn’t always get that menu to come up (or
open). Polk’s has indicated that the “UP” and
“DOWN” mode buttons must be pressed at
the same time or you won’t get into Track 2.
This was done intentionally so you don’t
accidentally get into that menu mode while
flying. Now you know why it’s a little
harder than you would like!
Polk engineers have told me it will be
possible to download program (software)
updates into your Tracker III at a later time.
Inside the battery compartment, to the left
side of the battery pack, is an area where a
memory stick can be inserted to allow you to
download any updates. I’m not sure if this is
intended for the modeler or only for Polk’s
service people.
I was cautioned that when you do an
update, you wipe out all your existing controldata
inputs and have to start from scratch. I
think I’ll stick with what I have rather than reenter
all my controls.
The eight-cell Ni-Cd rechargeable battery
pack has its own connector and can easily be
removed for testing or replacement. Many of
my fellow club members have gone to highercapacity
packs with the same physical size,
such as 1500-2300 mAh NiMH, to get more
operating time. The rationale is that if you use
only this transmitter all day, with many
aircraft, you could run out of power. So that is
something you should consider.
By the way, when you remove the battery
pack you do not lose any of your programmed
memory. It is all saved, even without power.
No frequency flag is provided with the
Tracker, and I guess that’s understandable
with a choice of 50 RC channels. I came up
with what I thought was a neat idea and ran it
in MA’s “Frequently Asked Questions”
column last year.
I use an approximately 4 x 4-inch square
of a 1/32-inch-thick white plastic (from a craft
store) with a clothespin mounted on one end.
On this square I write the channel number in
use with an erasable black marker. I attach
that marker to the rear of the Tracker with
hook-and-fastener tape so it is always easy for
me to access.
Each time I change the channel I wipe off
the old number and write the new one. On the
rear of this plastic square I have a list of each
memory position, channel number, and
aircraft name as a reference. I keep that list on
my PC and update it occasionally, printing a
copy to paste on the back of the square. Look
at the photos and you will realize how simple
it is.
I now have a new “standard bearer” RC
transmitter that is capable of controlling all
my aircraft. With 99 memory positions I
probably won’t run out for a long time. I like
the fact that I still have my conventional trim
levers. Best of all, this is an easy system to
operate. The Seeker receivers just add frosting
to the cake. Changing frequencies and models
while at the flying field couldn’t be any
easier! MA
Bob Aberle

56 MODEL AVIATION
Product Review: Polk’s Hobby Tracker III RC System
BOB ABERLE
THE TRACKER III transmitter is a “nextgeneration”
product. The original Tracker
dates back to the early 1990s, but I obtained
my Tracker II transmitter and companion
Seeker II receiver just two years ago. It is
currently my primary operating system, and
I’ll tell you why!
Polk’s Hobby has been involved with
synthesized RC systems for almost 15 years.
It has pursued what many of us consider the
better approach.
The Tracker transmitter can broadcast
signals on all 50 of our aircraft RC channels
throughout the 72-73 MHz band. A built-in
scanning receiver (inside the transmitter)
listens to make sure the channel is clear
before allowing it to go “on the air.”
The Seeker II or Seeker 6 receivers can set
themselves to the transmitter channel, making
it easy to find an open or clear channel
anytime you want to fly. That’s what the
Tracker and Seeker do well. But I want to tell
you why I think Polk’s Hobby does it a better
way.
Synthesizers are not new to our hobby. I
flew the Kraft Channel Master system more
than 20 years ago. As do many of the presentday
synthesized RC systems, the transmitter
had essentially an adjustable frequency
module. It contained two tiny rotary dials. If
you wanted to operate on channel 42, you
dialed a “4” and a “2” and you were set.
However, those dials were (and still are in
many cases) located on the inside of the
module. That being the case, you had to
remove the module (unplug it), rotate the
dials, and plug it back in. Once you did that, it
was no longer obvious what channel you
were on since you could no longer see the two
dials. Many of us found that repeatedly
plugging in and unplugging the radio-
A close look at Polk’s Hobby Tracker III RC synthesized transmitter. Besides the
frequency, it can also store individual programs for up to 99 models.
L: eight-channel-function Seeker II receiver. R: six-channel Seeker 6—ideal for small
models. “Set” button, plugged into both receivers, is used to set frequency to match
transmitter.
Tracker III system includes transmitter
and (L-R) switch harness, single servo,
four-cell Ni-Cd receiver battery pack, and
dual-output battery charger. Your choice
of Seeker receiver is also included.
January 2006 57
The two LEDs indicate power and RF output. Red indicates that
the transmitter is not broadcasting a signal. Green indicates that
the transmitter is “on-the-air.”
The “C” switch is typically assigned to elevator dual rate control;
the “D” switch can be used for rudder dual rate. Rotary knob is
for CH 7 auxiliary control. At top right corner is three-position
switch for CH 8 auxiliary function.
Rotary knob is CH 6 auxiliary control. The “A” switch has been
assigned to aileron dual rate or expo rate control. At right is new
momentary contact trainer switch. At top left is another threeposition
switch for CH 5 function.
Heart of the Tracker III computer system requires the use of six
control input buttons. The instruction manual explains their
function; it is easy to learn.
Dual output charger can charge transmitter’s eight-cell Ni-Cd
battery pack and four-cell receiver battery pack. This is a C/10, or
“overnight,” charger.
Photos courtesy the author
• Built-in scanning receiver checks the entire 72-73 MHz RC
band before allowing the signal to go “on the air.” Eliminates
the chance of causing local interference at the flying field.
• Ninety-nine memory positions capable of operating any FM RC
receiver on the market.
• Synthesized to operate, at your selection, any of the 50 RC
aircraft channels.
• Channel selection can be stored in the memory positions and
does not require removing a module and rotating any dials.
• Models can be named to show up on the LCD display for
identification purposes.
• Companion Seeker synthesized receiver can be “tuned” to the
Tracker frequency without being removed from the aircraft.
Pluses and Minuses
+
-• Memory positions 11-99 need to be initialized.
58 MODEL AVIATION
No frequency flag comes with the system. Bob created his own
from white plastic sheet material. He writes the channel number
in use on the tag with an erasable marking pen.
Bob keeps a list of all memory positions in use, their frequency,
and aircraft names on the back of his channel marker.
First display appearing each time you turn the power switch on
shows operating channel and current operating frequency. Present
operating voltage is at lower right.
In Track 1 menu you do such things as assign memory positions,
channel number, and aircraft name. In this screen the channel of
operation was set to 36, which is 72.510 MHz.
The model-memory position can be named with as many as eight
characters. The [#01] indicates model memory selected.
To set up and store data above memory position 10, you must
copy a basic set from a lower memory number. Number 1
memory is being copied to set up new memory 11 position.
Typical data point in Track 2 menu system is important Trim
Memory that lets you store trim positions for a particular model
in memory. Following the procedure, all trim levers can physically
be put back to center.
After making any control adjustments in Track 1 and 2 menus,
you must do a “DATA SAVE” before turning power off.
Otherwise changes will be lost.
frequency (RF) modules eventually wore out
the connector pins.
If you have a transmitter with six or seven
model programs, you may be using several,
as many as six or seven, different RC
channels. In the course of one day at the field
and having several models with you, you
might be pulling and resetting that
synthesized module many times.
How does Polk’s Hobby address this
problem? It has resorted to a pure electronic
(solid-state) approach. There are no dials to
rotate; it is all done much as it would be on a
computer.
When you are first setting up a new
Screwdriver points to new trainer-cable jack. The cable must be
purchased separately and will allow you to connect to a second
transmitter for instructional purposes.
aircraft, hold down the “UP” mode button
while turning on the power. That will bring up
the Track 1 menu, which you use for basic
setup or when changing from one model
memory to another. For safety’s sake, when in
the Track 1 menu you are not broadcasting a
signal and therefore can’t possibly interfere
with anyone else at your flying field.
Select a new memory spot (1-99), then
select a channel that is the same frequency as
your receiver. You do this by pressing the
“INC” or “DEC” button on the front of the
transmitter. Keep pressing until the channel
number and frequency appear on the LCD
screen.
Finally, use the mode button to scroll to
“Model Data Save,” and then press the
“DATA [+]” button. You have now saved that
particular channel in that specific memory
position. You can also name your model for
future use, but I’ll get into that later.
When at the flying field, all you need to do
to go from one model memory to another is
call up the Track 1 menu and select your
memory position for that aircraft. It will
always be on the correct channel (operating
frequency), and you don’t have to rotate any
dials or remove a module. The Tracker III
transmitter has 99 memory positions, so it can
handle a load of airplanes!
Another important feature is the built-in
scanning receiver. Every time you turn on the
transmitter power switch, the scanning
receiver checks your intended operating
frequency to see if it is clear. It will tell you to
wait, and then it will tell you it’s okay to fly.
If someone is already on that particular
channel, the receiver will not let you
broadcast a signal until that person turns off.
This scanning receiver is so sensitive that
we’ve found it possible to detect third-order
intermodulation (3IM) interference at the
local flying field.
The effects of 3IM happen when two
transmitters operating on precisely the right
combination of frequencies produce
interference on a third signal. That third
frequency can, in many cases, be picked up by
the scanner.
If we get a “wait” message at our field, we
generally call out, “Who’s on channel so-andso?”
If the pilots who are flying yell out
different channels, you can be sure 3IM is
causing the problem and you best wait until
one of them turns off. This is an excellent
safety feature and the reason why my local
club recommends the use of this particular
transmitter.
Still another neat feature is the two
synthesized receivers that Polk’s Hobby
offers: the Seeker II (eight channel) and the
Seeker 6 (six channel, small, and weighing
0.54 ounce). These receivers are not exactly
new, but they are great complements to the
Tracker transmitter.
The eight-channel receiver is a larger unit
that will be more comfortable in larger and
heavier models—especially those that require
as many as eight different channel functions.
The newer Seeker 6 is an excellent choice for
small aircraft such as park flyers and backyard
flyers.
Again, the advantage Polk’s Hobby
provides is that no dials have to be rotated to
obtain a new channel or frequency. Actually,
tuning one of these receivers to the
synthesized Tracker transmitter is a snap.
Set your Tracker to a channel that is not in
use at your flying field. Fully extend the
antenna. Bring that transmitter antenna in
close proximity to the Seeker receiver antenna
so that they are almost touching.
There is a “SET” button that exits the
receiver on a short cable. You can locate this
switch so that it is accessible from the outside
of the aircraft fuselage. Hold down that
“SET” button while you turn on the receiver
power. The servo plugged into the numberone
position will pulse back and forth. It will
do that for approximately five seconds and
then the servo will stop.
At that instance the Seeker receiver is
locked onto the Tracker transmitter’s current
operating frequency. The receiver will keep
that frequency locked in, even when the
power is turned off. It will not change until
you physically change it. The beauty of this is
that you don’t have to dive into your fuselage,
remove the receiver, and rotate a couple dials
to change the channel.
The Tracker transmitter will operate any
FM (Pulse Position Modulation, or PPM)
receiver on 72 MHz. You can even select high
or low FM deviationAirtronics and JR receivers, which are on
high deviation (positive shift), and FMA
Direct, Futaba, Hitec, and Ace receivers,
which are on low deviation (negative shift).
Likewise, the Seeker receivers will work with
any other FM (PPM) transmitter since they
automatically detect deviation.
How does Polk’s Hobby market its
Tracker III transmitter and the Seeker
receivers? For the US market the company
offers systems on the 72 MHz aircraft
channels and 75 MHz for the surface-vehicle
market.
An eight-channel Tracker III transmitter
with a Seeker 6 receiver, dual-output charger,
four-cell Ni-Cd receiver battery pack, a
Polk’s servo (item PLK12003), and a
miniswitch currently sells for $180. The
rationale for offering a single servo is that
most modelers have their own preferences,
and there is no point in supplying four servos
that might never be used. Polk’s supplies one
to let you get accustomed to the system
operation.
The system I just described but with an
eight-channel Seeker II receiver is $200.
There are other combinations, as well as
systems on 35 and 40 MHz for the European
market. You can check out these options on
Polk’s Hobby’s Web site.
Tracker III Details: Now that you are
familiar with the Tracker and Seeker
components, I’ll explain what is different
with the new Tracker III transmitter. You
will notice a newly designed and stylish
case with more rounded corners and a
definitely cleaner appearance. This case is
much more comfortable to hold, and I’m
in favor of that. Without all those fancy
facets, nooks, and crannies, the case is
much easier to keep clean too.
A provision has been added for a trainer
cable that will allow you to tie in two
transmitters for training purposes. A jack is
provided for the cable, and there is a
momentary contact switch (designated “TR”)
to allow the instructor to take control when
the student gets into trouble. The trainer cable
must be purchased separately.
That trainer jack is also compatible with a
simulator cable that is available as an option.
It will allow you to use your Tracker
transmitter as a control input box to operate
simulator software installed or downloaded to
your PC.
Another nice feature is the ability to name
your model, with up to eight characters (using
alpha, numeric, and certain symbols), for
each model-memory position and have that
name appear on the LCD screen every time
you turn on the power.
However, I must point out that the modelmemory
position number (1-99) no longer
appears on the LCD screen. I was
disappointed at first, but I came up with an
interesting situation.
I was using memory position 12 and set
my operating frequency to CH 12. When I
turned the transmitter on I ended up with 12
and 12, and it looked kind of confusing. So in
retrospect I think having the eight-character
naming is just fine.
One thing you lose on the Tracker III is
the RF output meter. In its place are red and
green LEDs. The red light glows when the
signal is not on the air or when the battery is
too low to operate. The green lights up when
a normal signal is being broadcast.
The digital readout of the transmitter
voltage still appears on the LCD screen when
in the normal operating display mode (every
time the power is turned on). There is a lowvoltage-
warning alarm, but it wasn’t
mentioned in the first edition of the
62 MODEL AVIATION
instruction manual. Rest assured that it will be
added quickly.
Some of the auxiliary switches are in
different locations than they were on the
Tracker II. At the two top corners of the case
there are still two switches (left for CH 5 and
right for CH 8). Both of those are now of the
three-position variety (they were formerly
two-position switches).
If you use one of these switches for the
retract function, you will have to remember to
go from one extreme to the other. The CH 8
three-position switch will be ideal for threeposition
flap settings. There are no labels on
these two switches, so it may be necessary to
add your own if you feel you need them.
There are three switches on the front
panel, designated “A,” “C,” and “D.” These
are typically for turning on and off dual rate
control and exponential (expo) rate control.
You can actually assign all the switches to
positions of your choice; this is done in the
Track 2 menu.
I set switch “A” for aileron dual rate/expo,
switch “C” for elevator, and switch “D” for
rudder. That leaves two more channel
functions (5 and 6) that can be operated by
rotating knobs. When you compare the
Tracker III and II, you will see that some of
these switches are in different locations; this
might get confusing if you are flying both
transmitters.
I won’t supply a specification box with
this review because Polk’s Hobby was
kind enough to place the entire Tracker III
operations manual and all the necessary
specifications in a PDF file on its Web site
at www.polkshobby.com/pdf/tracker3
manual.pdf.
Keep in mind that you get dual rate
control and expo rate control on three channel
functions: ailerons, elevator, and rudder.
Servo reversing and endpoint adjustment are
available on all channels.
All four primary channel functions have
trim levers—not digital buttons (which I
don’t favor!). It’s the old fashioned way; the
trim lever’s position indicates roughly the
amount of trim and in what direction.
You still have the all-important Trim
Memory function that lets you save the trims
for each model and then return the trim levers
to their neutral (center) position. You can tell
when the trim lever is centered because a
“beep” will sound.
As does the Tracker II, this new model
requires that you manually “SAVE” after
having made control-input changes, prior to
turning off the transmitter’s power. This
might prove to be confusing to some RC
fliers who own computer-type transmitters
that save the command inputs automatically
when the power is turned off.
When you get down to it, the nice thing
about the Tracker III is that it will
probably be the only transmitter you use
(since it can operate any brand of receiver
on any of the 50 RC channels). That being
the case, you will become totally familiar
with its functions and never be confused
because you won’t be going fromappropriate to note that programming the 99
memory positions requires a slightly different
technique on the Tracker III. The first 10
positions are “business as usual”; you just set
your model name, frequency, and all your
control inputs into each position.
However, Polk’s did not program all the
data into positions 11-99 because it takes so
much of the service technician’s time. The
manual instructs you on how to cope with this
problem.
Primarily, what has actually happened is
that the data for the travel volumes, trim rates,
and dual rates are set at zero. This is the initial
root program setting. None of the channels
will work until the values are raised above
0%. Model programs 1-10 already have these
functions set to 100%.
One clue that the model program hasn’t
been initialized is that you will see odd
characters (I call them dingbats) where the
model name would go. You’ll find these
characters again in other parts of the Track 1
and 2 menus that will indicate that this feature
has been inhibited and needs to be set. If you
fail to change the data, it will seem as though
your receiver isn’t responding, naturally
because the control functions have no value.
Bringing the program up to date, as it is in
model memory positions 1-10, isn’t hard, but
it is tedious and time consuming. You just
move through the program features as you
normally would and use the command buttons
to bring the values up on every channel.
The easiest way I found to avoid
programming every model is to set up
memory 1 as a typical aircraft and assign the
switches that will be most commonly used.
Then each time I go to set up a new model, all
I have to do is copy memory 1 into the new
position. I might copy 1 to 14, or 67 for that
matter. Then I can name the new position and
set the operating frequency and all the
controls peculiar to that new model.
I found that when trying to get into the
Track 2 menu to adjust the various controls, I
couldn’t always get that menu to come up (or
open). Polk’s has indicated that the “UP” and
“DOWN” mode buttons must be pressed at
the same time or you won’t get into Track 2.
This was done intentionally so you don’t
accidentally get into that menu mode while
flying. Now you know why it’s a little
harder than you would like!
Polk engineers have told me it will be
possible to download program (software)
updates into your Tracker III at a later time.
Inside the battery compartment, to the left
side of the battery pack, is an area where a
memory stick can be inserted to allow you to
download any updates. I’m not sure if this is
intended for the modeler or only for Polk’s
service people.
I was cautioned that when you do an
update, you wipe out all your existing controldata
inputs and have to start from scratch. I
think I’ll stick with what I have rather than reenter
all my controls.
The eight-cell Ni-Cd rechargeable battery
pack has its own connector and can easily be
removed for testing or replacement. Many of
my fellow club members have gone to highercapacity
packs with the same physical size,
such as 1500-2300 mAh NiMH, to get more
operating time. The rationale is that if you use
only this transmitter all day, with many
aircraft, you could run out of power. So that is
something you should consider.
By the way, when you remove the battery
pack you do not lose any of your programmed
memory. It is all saved, even without power.
No frequency flag is provided with the
Tracker, and I guess that’s understandable
with a choice of 50 RC channels. I came up
with what I thought was a neat idea and ran it
in MA’s “Frequently Asked Questions”
column last year.
I use an approximately 4 x 4-inch square
of a 1/32-inch-thick white plastic (from a craft
store) with a clothespin mounted on one end.
On this square I write the channel number in
use with an erasable black marker. I attach
that marker to the rear of the Tracker with
hook-and-fastener tape so it is always easy for
me to access.
Each time I change the channel I wipe off
the old number and write the new one. On the
rear of this plastic square I have a list of each
memory position, channel number, and
aircraft name as a reference. I keep that list on
my PC and update it occasionally, printing a
copy to paste on the back of the square. Look
at the photos and you will realize how simple
it is.
I now have a new “standard bearer” RC
transmitter that is capable of controlling all
my aircraft. With 99 memory positions I
probably won’t run out for a long time. I like
the fact that I still have my conventional trim
levers. Best of all, this is an easy system to
operate. The Seeker receivers just add frosting
to the cake. Changing frequencies and models
while at the flying field couldn’t be any
easier! MA
Bob Aberle