1/16 SUMMIT • 9
THE TRAXXAS TQ RADIO SYSTEM
RADIO SYSTEM TERMINOLOGY
Please take a moment to familiarize yourself with these radio and power
system terms. They will be used throughout this manual.
BEC (Battery Eliminator Circuit)
- The BEC can either be in the receiver or in
the ESC. This circuit allows the receiver and servos to be powered by the
main battery pack in an electric model. This eliminates the need to carry a
separate pack of 4 AA batteries to power the radio equipment.
Channel
- The 27 MHz
frequency band is divided
into 6 channels so that
up to six models can be
operated simultaneously.
Each channel is referred to
by its flag color and channel
number, as shown on the
chart to the right.
Clearing your frequency
- A routine, verbal check to make sure nobody else
in your area is operating on the same channel. Always clear your frequency
by calling out your channel number before operating your model. Wait or
move to another area if your channel is already being used.
Crystal (X-tal)
- The plug-in device that determines which channel the radio
system will operate on. For each channel, there are two crystals, one for the
receiver and one for the transmitter. Of those two crystals, the one marked
with the lower number (.455 MHz lower) must be inserted into the receiver.
Current
- Current is a measure of power flow through the electronics, usually
measured in amps. If you look at wire like a garden hose, current is a
measure of how much water is flowing through the hose.
ESC (Electronic Speed Control)
- An electronic speed control is the electronic
motor control inside the model. Electronic speed controls use power more
efficiently than mechanical speed controls so that the battery runs longer.
An electronic speed control also has circuitry that prevents loss of steering
and throttle control as the battery loses its charge.
Frequency band
- The radio frequency used by the transmitter to send signals
to your model. All Traxxas RTR models operate on a 27 MHz frequency band.
kV Rating
- Brushless motors are often rated by their kV number. The kV
rating equals no-load motor rpm with 1 volt applied. The kV increases as
the number of wire turns in the motor decreases. As the kV increases, the
current draw through the electronics also increases.
LiPo
- Abbreviation for Lithium Polymer. Rechargeable LiPo battery packs are
known for their special chemistry that allows extremely high energy
density and current handling in a compact size. These are high performance
batteries that require special care and handling. For advanced users only.
mAh
– Abbreviation for milliamp hour. A measure of the capacity of the
battery pack. The higher the number, the longer the battery will last
between recharges.
Neutral position
- The standing position that the servos seek when the
transmitter controls are at the neutral setting.
NiCad
- Abbreviation for nickel-cadmium. The original rechargeable hobby
pack, NiCad batteries have very high current handling, high capacity, and
can last up to 1000 charging cycles. Good charging procedures are required
to reduce the possibility of developing a “memory” effect and shortened
run times.
NiMH
- Abbreviation for nickel-metal hydride. Rechargeable NiMH batteries
offer high current handling, and much greater resistance to the “memory”
effect. NiMH batteries generally allow higher capacity than NiCad batteries.
They can last up to 500 charge cycles. A peak charger designed for NiMH
batteries is required for optimal performance.
Receiver
- The radio unit inside your model that receives signals from the
transmitter and relays them to the servos.
Resistance
- In an electrical sense, resistance is a measure of how an object
resists or obstructs the flow of current through it. When flow is constricted,
energy is converted to heat and is lost. Traxxas power systems are optimized
to reduce electrical resistance and the resulting power-robbing heat.
Servo
- Small motor unit in your model that operates the steering mechanism.
Transmitter
- The hand-held radio unit that sends throttle and steering
instructions to your model.
Trim
- The fine-tuning adjustment of the neutral position of the servos, made by
adjusting the throttle and steering trim sliders on the face of the transmitter.
Thermal Shutdown Protection
- Temperature sensing electronics used
in the electronic speed control detect overloading and overheating of
the transistor circuitry. If excessive temperature is detected, the unit
automatically shuts down to prevent damage to the electronics.
2-channel radio system
- The TQ radio system, consisting of the receiver, the
transmitter, and the servos. The system uses two channels: one to operate
the throttle and one to operate the steering.
Voltage
- Voltage is a measure of the electrical potential difference between
two points, such as between the positive battery terminal and ground.
Using the analogy of the garden hose, while current is the quantity of water
flow in the hose, voltage corresponds to the pressure that is forcing the
water through the hose.
