Spektrum SPMAR6255 - Manual (Page 3)

Receiver Installation
Airplanes with significant carbon fiber construction can create an RF shielding effect,
reducing range. The AR6255 is designed to overcome these critical RF issues in
carbon airplanes by outfitting the aircraft with two external antennas at specific
points that will ensure secure RF coverage from all angles of the aircraft.
Feeder Antennas
The AR6255 incorporates two feeder antennas, which are designed to be easily
mounted through the fuselage in carbon airplanes. The receiver has two 4-inch
feeder antennas. Each feeder antenna includes a coaxial portion (which can be
thought of as an extension) and an exposed 31mm tip antenna. The last 31mm is the
active portion of the antenna.
105mm
199mm 31mm
31mm
Red LED Hold Indicator
The AR6255 features a red LED (labeled with H) that indicates the number of holds
that have occurred since the receiver was last powered on. The LED will flash the
number of holds then pause (e.g., flash, flash, flash, pause, flash, flash, flash,
pause indicates three holds occurred since the receiver was last turned on). Note
that holds are reset to zero when the receiver is turned off. During the first flights of
a new airplane, it’s recommended to check the red LED hold indicator. If it’s flashing,
it’s important to optimize the installation (move or reposition antennas) until no
hold occurs. On later flights, the LED Hold Indicator can be used to confirm RF link
performance.
Step 1. Identifying the Type of Carbon Aircraft
While some Hand Launch Gliders and F5D airplanes are full carbon construction,
many only use carbon in areas that require extra strength. Some of the latest
aircraft are constructed with 2.4GHz friendly fuselages, meaning that the forward
section of the fuselage is constructed from non-conductive materials like fiberglass
and Kevlar that don’t affect RF. The first step in a proper installation is identifying the
type of fuselage.
A- Full Carbon
All components of the airplane including the entire fuselage, the wing and tail are
constructed of carbon fiber or have a carbon fiber weave throughout the aircraft.
EN
Full Carbon External Antennas