Tips On Using 2.4Ghz Systems - Spektrum DX5e User Manual

3. If using a regulator, it's important the above tests are
done for an extended period of 5 minutes. When current
passes through a regulator, heat is generated. This
heat causes the regulator to increase resistance, which
in turn causes even more heat to build up (thermal
runaway). While a regulator may provide adequate
power for a short duration, it's important to test its
ability over time as the regulator may not be able to
maintain voltage at significant power levels.
4. For really large aircraft or complex models (for example
35% and larger or jets), multiple battery packs with
multiple switch harnesses are necessary or in many
cases one of the commercially available power boxes/
busses is recommended. No matter what power systems
you choose, always carry out test #1 above making sure
that the receiver is constantly provided with 4.8 volts or
more under all conditions.
5. The latest generation of Nickel-Metal Hydride batteries
incorporates a new chemistry mandated to be more
environmentally friendly. These batteries, when charged
with peak detection fast chargers, have a tendency to
false peak (not fully charge) repeatedly. These include
all brands of NiMH batteries. If using NiMH packs be
especially cautious when charging making absolutely
sure that the battery is fully charged. It is recommended
to use a charger that can display total charge capacity.
Note the number of mAh put into a discharged pack to
verify it has been charged to full capacity.
12

TIPS ON USING 2.4GHZ SYSTEMS

Your DSM2 equipped 2.4GHz system is intuitive to operate,
functioning nearly identically to FM systems. Following are
a few common questions from customers:
1. Q: Which do I turn on first, the transmitter or the
receiver?
A: It doesn't matter, although it is suggested to turn the
transmitter on first. If the receiver is turned on first,
the throttle channel doesn't put out a pulse position at
this time, preventing the arming of electronic speed
controllers, or in the case of an engine powered aircraft,
the throttle servo remains in its current position. When
the transmitter is then turned on the transmitter scans
the 2.4GHz band and acquires two open channels. Then
the receiver that was previously bound to the transmitter
scans the band and finds the GUID (Globally Unique
Identifier code) stored during binding. The system then
connects and operates normally. If the transmitter is
turned on first, the transmitter scans the 2.4GHz band
and acquires two open channels. When the receiver
is turned on, the receiver scans the 2.4GHz band
looking for the previously stored GUID. When it locates
the specific GUID code and confirms uncorrupted
repeatable packet information, the system connects and
normal operation takes place. Typically this takes 2 to 6
seconds.
2. Q: Sometimes the system takes longer to connect and
sometimes it doesn't connect at all. Why?
A In order for the system to connect (after the receiver
is bound), the receiver must receive a large number
of continuous (one after the other) uninterrupted
perfect packets from the transmitter. This process is
purposely critical of the environment ensuring that
it's safe to fly when the system does connect. If the
transmitter is too close to the receiver (less than 4
feet) or if the transmitter is located near metal objects
(metal transmitter case, the bed of a truck, the top of a
metal work bench, etc.) connection will take longer. In
some cases connection will not occur as the system
is receiving reflected 2.4GHz energy from itself and is
interpreting this as unfriendly noise. Moving the system
away from metal objects or moving the transmitter away
from the receiver and powering the system up again will
cause a connection to occur. This only happens during
the initial connection. Once connected the system is
locked, and should a loss of signal occur (failsafe), the
system connects immediately (4ms) when signal is
regained.
SPEKTRUM DX5e • RADIO USER'S GUIDE