Spektrum SPMMSJR9 - Manual (Page 26)

Spektrum Air Module 
Spektrum’s Flight Log is compatible with Spektrum AR9000 receivers. The Flight
Log displays overall RF link performance as well as the individual internal and
external receiver link data. Additionally it displays receiver voltage.
Using the Flight Log
After a flight and before turning off the receiver or transmitter, plug the Flight Log
into the Data port on the AR9000 receiver. The screen will automatically display
voltage i.e. 6v2= 6.2 volts
Note: When the voltage reaches 4.8 volts or less, the screen will flash
indicating low voltage.
Press the button to display the following information:
A - Antenna fades on internal antenna A
B - Antenna fades on internal antenna B
L - Antenna fades on the left external antenna
R - Antenna fades on the right external antenna
F - Frame loss
H - Holds
Antenna fades—represents the loss of a bit of information on that specific antenna.
Typically it’s normal to have as many as 50 to 100 antenna fades during a flight.
If any single antenna experiences over 500 fades in a single flight, the antenna
should be repositioned in the aircraft to optimize the RF link.
Frame loss—represents simultaneous antenna fades on all attached receivers. If
the RF link is performing optimally, frame losses per flight should be less that 20.
A hold occurs when 45 contiguous (one right after the other) frame losses occur.
This takes about one second. If a hold occurs during a flight, it’s important to
re-evaluate the system, moving the antennas to different locations and/or checking
to be sure the transmitter and receivers are all working correctly.
Note: A servo extension can be used to allow the Flight Log to more
conveniently be plugged in without having to remove the aircraft’s hatch
or canopy. On some models, the Flight Log can be plugged in, attached
and left on the model using double-sided tape. This is common with
helicopters, mounting the Flight Log conveniently to the side frame.
Flight Log—Optional for the AR9000