Multiplex Profi TX Operating Instructions Manual page 50

Transmitter
PROFI TX
Procedure
1. If the model is fitted with a power system, switch it off!
Press and hold the §button on the transmitter as you switch the transmitter
2.
on.
3. Switch on the receiver.
4. In the Servo > Test run menu, activate the test run for a control function,
e.g. Elevator. This allows you to check that the receive system responds to
control commands with distinct, regular movements of the control surfaces.
5. Increase the distance between transmitter and model. You have reached the
range limit when the servos start to jitter.
6. Repeat the check with the power system running. Secure the model. Perform
the check using throttle positions that vary between idle and full throttle. In
case of electric power systems, the most significant interferences occur at
half throttle.
The range should not diminish significantly.
7. Otherwise, eliminate the cause of the interference (power system, installed
position of the receive system with power supply).
Factors influencing the radio range
The following factors have significant influence on the radio range:

Environmental conditions
Hilltops, ground characteristics, type of terrain, and the atmospheric
conditions affect radio range.

Receiver technology and sophistication
Technically sophisticated receivers have a greater range than simple,
cheap receivers.

Installation situation in the model
Installation position / arrangement of the aerials and the distance to
batteries, power systems, servos, ignition systems, metal / carbon fibre
parts influence the radio range.
Binding
The binding procedure binds the receiver with the transmitter.
M-LINK uses "frequency hopping" and "spread spectrum".
No fixed transmission channel is used for "frequency hopping", but all 39 channels
are used in a sequence that is defined by the transmitter.
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