Tower Hobbies 424 User Manual

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®

FEATURES

SLT TECHNOLOGY, TX-R, & COMPATIBLE RECEIVERS

It is strongly recommended to completely read this manual before use!
Damage resulting from misuse or modification will void the warranty.

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Power LED with low voltage warning

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Wireless training function

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Digital trims for aileron, elevator, rudder

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Gimbals with smooth ball-bearing feel

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Charge jack for optional rechargeable batteries

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Failsafe in the included receiver

This radio includes SLT technology to ensure a strong,
clear, frequency-hopping 2.4GHz signal is emitted, and
that your compatible receiver accepts a signal only from
your transmitter. Linking the included Tower Hobbies
brand receiver is accomplished by the simple push of a
button. This radio is also compatible with all transmitter­ready aircraft bearing the Tx-R™ logo, and Tactic and other brand receivers
having the SLT* protocol.

* Make sure optional receivers have the genuine SLT protocol before use with this radio.

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PREFLIGHT PREPARATIONS

Pay special attention to all precautions and warnings to ensure the safest operation.
This radio system is intended for sport and recreational fl ying of R/C models only.
Tower Hobbies is not responsible for incidental damage or personal harm resulting
from improper usage or unauthorized alteration of this product. Physical modifi cations
of any component in this system will void the warranty. For best results, make sure
all batteries are new (if alkalines) or fully charged (if rechargeable). Connect servos
to the receiver and try to adjust the radio on the workbench while reading along with
this instruction manual to understand all functions.

TRANSMITTER

Reversing Switches

On/Off Switch

Trim Lever

Power Indicator LED

Neck Strap Eyelet

Trainer Switch

%
,
%
6
!
4
/
2

AILERON

4
(
2
/
4
4
,
%

RUDDER

INPUT POWER: This transmitter (Tx) requires four “AA”

batteries. Non-rechargeable 1.5V alkaline or rechargeable

1.2V nickel-cadmium (NiCd) or nickel-metal hydride
(NiMH) cells can be used (not included). Do not mix old
and new cells, or mix non-rechargeable alkaline cells with
rechargeable NiCd or NiMH cells, etc. See the Accessories
section at the end of this manual for optional batteries.

To install the batteries, slide open the battery door. Install
the batteries as shown in the diagram. Make sure to note
the proper polarities on each cell. Close the battery door.

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CHARGE JACK: A built-in charge jack is included for recharging of NiCd or NiMH

rechargeable batteries. This jack can accept charge leads designed for Tactic brand
transmitters, with the center pin being positive polarity. This jack is NOT compatible
with charge leads designed for other radio brands. If using rechargeable batteries,
make sure to only use a charger which is compatible with those battery types.
Make sure the Tx power switch is OFF to charge the batteries through the charge
jack. Connect the charge lead to the charger fi rst, then to the Tx charge jack. Follow
the instructions included with the charger. Charge leads such as TACP0101 – Tx
Rx Charge Leads from Tactic are recommended for use with this transmitter.

IMPORTANT: Do not operate an R/C model with weak batteries as it
could result in reduced range and/or possible loss of control. Failure to

obey this warning could result in destruction of the model and possible
bodily injury. Only use the charge jack to recharge rechargeable cells. Never attempt
to recharge alkaline batteries. Do not accidentally short circuit the terminals inside
the charge jack as permanent damage could result and void the warranty. Do not
charge batteries at currents greater than 1 amp through this charge jack. Misuse,
improper charging, or over-charging of rechargeable cells can result in damage to
the cells that could include cell rupture, explosion, or fi re!!

ON/OFF POWER CONTROL AND LED WITH LOW BATTERY ALARM:

Move the power switch to the “ON” position. The red LED should illuminate. If the LED
stays on constantly the batteries have ample power for a fl ight. If the LED is fl ashing,
and also accompanied by beeps, the transmitter’s batteries have become weak and
require replacement or recharge prior to attempting a fl ight. If this alarm activates
during fl ight land the aircraft immediately to avoid a possible loss of all control!

GIMBAL STICKS: The length of each control
stick can be adjusted for preferred feel. With a
5/64" hex wrench, loosen the set screw inside the
tip of the stick. Turn the tip of the stick counter­clockwise to lengthen the stick. Turn the tip of the
stick clockwise to shorten the stick. Tighten the
set screw once the desired length is found.

AILERON: Channel 1 controls the airplane’s ailerons. These moveable surfaces
at the end of the wings rotate the airplane about an imaginary line which extends
from the airplane’s nose to the tail called the “roll axis”. Moving this stick to the

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right should cause the aileron on the right wing to move upwards, causing the right
wing to dip and bank the plane to the right. Conversely, moving the stick to the left
should cause the left wing to dip and bank the plane to the left. If movement of
the stick causes the aileron surfaces to move in the opposite direction, move the
reversing switch for aileron channel 1 to the opposite position.

ELEVATOR: Channel 2 controls the airplane’s elevator. These moveable surfaces
on the tail rotate the airplane about an imaginary line which extends through the
center of both wings from wing tip to wing tip, known as the “pitch axis”. Moving
the elevator stick upwards should cause the plane’s elevators to move upwards,
causing the nose of the airplane to rise. Moving the stick down should cause the
plane’s elevators to move down, and cause the nose of the airplane to drop. If
movement of the stick causes the elevator surface to move in the opposite direction,
move the reversing switch for elevator channel 2 to the opposite position. To help
maintain the airplane’s altitude while performing a bank turn, gently pull back on
the elevator stick while defl ecting the ailerons.

THROTTLE: Channel 3 controls the airplane’s throttle. Pushing the throttle stick
forward should cause the R.P.M. of an electric motor or combustion engine to
increase. Pulling the throttle stick down (away from the Tx handle) should cause
the motor or engine’s R.P.M. to decrease. If movement of the stick causes the
throttle to move in the opposite direction, move the reversing switch for throttle
channel 3 to the opposite position.

RUDDER: Channel 4 controls the airplane’s rudder. This moveable surface on
the tail moves sideways and rotates the airplane about an imaginary line from
the bottom of the airplane’s fuselage upward through the center to the top of the
fuselage, known as the “yaw axis”. Moving the rudder stick to the right should cause
the rudder to move to the right, and cause the airplane’s nose to point to the right.
Moving this stick to the left should cause the rudder to move to the left, and cause
the airplane’s nose to point to the left. Using the rudder along with aileron controls
can point the airplane’s nose into a turn without pitching up or sliding through the
turn. If movement of the stick causes the rudder surface to move in the opposite
direction, move the reversing switch for rudder channel 4 to the opposite position.

TRIMS: Each of the four channels includes a trim lever, located directly adjacent
to the main control stick. Trim levers are used to fi nely adjust the center position of
the respective channel.

The trims for aileron, elevator, and rudder channels function digitally. The levers
always rest at mechanical center position. Briefl y pressing the spring-loaded lever
to either side of center position will adjust the center position of the respective
channel electronically, and can be observed on the servo. Holding the trim lever
to either side of center will cause the servo output to rotate repeatedly. Finely
trim each of these channels so that during fl ight the model does not veer in an
unwanted direction when the main sticks are released and back at center position.

The throttle channel includes a “mechanical” or analog trim lever. This trim lever can
be physically moved up or down and rest at any point in the range of movement.
The mechanical position of the lever will adjust the throttle channel’s electronic
position, and can be observed on the servo. This can fi nely adjust the engine/

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motor’s speed, and is especially useful at low speeds when the model is on the
ground - and only functions when the main throttle stick is below 50% full throttle.
When using a combustion engine use the throttle trim to precisely determine the
engine’s preferred idle point.

REVERSING SWITCHES: A reverse switch is included for each channel.
Changing the position of a reversing switch changes the direction of movement
for that respective channel. Moving the position of the reversing switch can often
be the easiest way to alter the direction of a servo’s movement aside from making
mechanical changes in the model. Refer to the transmitter’s faceplate to properly
identify the different reversing switches. See the model’s instructions for specifi c
details relating to operation of the model.

TRAINER FUNCTIONS

The Tower Hobbies 424 radio includes a wireless trainer function. This radio can
also be connected by wireless means to another Tower Hobbies 424 transmitter or
Tactic™ brand transmitter having the wireless trainer function for the purpose of
teaching a student how to fl y. It’s not possible to connect this radio to other brand
radios for wireless training. This radio can be used either by the teacher or student.

IMPORTANT! Before operating a model in training situations make

sure the reverse settings and trim adjustments for all channels match

on both the teacher and student’s transmitters. Failure to do this could
cause the model to suddenly veer in an unexpected manner when the teacher’s
trainer switch is activated. Proper matching of settings is especially important for
the throttle channel!

1. Link the radio being used by the teacher to the receiver inside the model. Then
turn the receiver’s power switch off.

2. Move the throttle stick for both the teacher and student’s transmitter to the idle
position. Locate both the teacher and student’s transmitter within 1 meter of
each other.

3. Turn the student’s transmitter power switch ON.

4. Pull and hold the trainer switch on the teacher’s transmitter. Then, turn the
teacher’s power switch ON.

5. Observe the LED on the teacher’s transmitter. If it fl ashes three times the
teacher’s transmitter has linked to the student’s transmitter.

6. Release the trainer switch on the teacher’s transmitter.

7. After the transmitters are linked, power can be applied to the receiver inside
the model and confi rm the teacher has full control of the aircraft. Make sure
both transmitters are kept within 15 feet of each other at all times while training.

8. During fl ight, pulling and holding the teacher’s trainer switch will transfer control
of the model to the student. Control of the model can be returned immediately
to the teacher by releasing the trainer switch.

9. After the model is back on the ground and the training session has ended and
power is safely removed from the model, turn OFF the power switch of both
transmitters. This will break the wireless link between the transmitters. Return
to step 1 above to re-establish the wireless link for additional training.