Spektrum SPMAR400 User Manual

Page 9

• All other channels will have no signal output.
Some analog servos may coast slightly, even though no signal is present.

This is normal.
After Connection
• When the transmitter is turned on, and after the receiver connects

to the transmitter, normal control of all channels return.

• If a signal loss occurs, the AR400 Failsafe drives the throttle servo

to its preset failsafe position (low throttle) that was set during binding.

• All other channels receive no output pulses/commands,

and are not active during failsafe.

Range Testing
Before each flying session, and especially with a new model, it is important

to perform a range check. All Spektrum aircraft transmitters incorporate a

range testing system which, when activated, reduces the output power.

30 paces (90 feet/28 meters)

1. With the model restrained on the ground, stand 30 paces

(approx. 90 feet/28 meters) away from the model.

2. Face the model with the transmitter in your normal flying position

and place your transmitter into range check mode.

3. You should have total control of the model at 30 paces (90 feet/28 meters).
4. If control issues exist, call a Horizon Product Support office nearest you.

Contact information is listed in the Warranty section.

Receiver Power System Requirements
Inadequate power systems that do not provide the necessary minimum voltage

to the receiver during flight have become the number one cause of in-flight

failures. Some of the power system components that affect the ability to

properly deliver adequate power include:
• Receiver battery pack (number of cells, capacity, cell type, state of charge)
• The ESC’s capability to deliver current to the receiver in electric aircraft
• The switch harness, battery leads, servo leads, regulators etc.
The AR400 has a minimum operational voltage of 3.5 volts; it is highly

recommended the power system be tested per the guidelines below.
Recommended Power System Test Guidelines
If you are using a questionable power system, (e.g. a small or old battery,

an ESC that may not have a BEC that will support high current draw, etc.),

perform the following test with a voltmeter.