FLEXCOMM
II
C-5000 (Non-Digital)
Installation Manual
150-1355-000 Rev. M
CONFIDENTIAL AND PROPRIETARY TO COBHAM
Page 149
APPENDIX A – CONTINUOUS AIRWORTHINESS INSTRUCTIONS
FOR FLEXCOMM II SYSTEM
1. Introduction
This document contains instructions for testing a FLEXCOMM II system on a periodic maintenance cycle to
assure continuous airworthiness. This document is intended to supplement the individual installation and user
manuals of the Flexcomm system components. The aircraft maintenance personnel should be in possession of
and refer to these manuals during inspections. The Flexcomm system includes a C-5000 control head, a RT-
5000, RT-30, RT-138F, RT-450 and/or a RT-406 radio (control of non-current production units such as the RT-
7200, RT-9600, and RT-9600F is possible with the C-5000 control head) and suitable antennas. The
recommended maintenance cycle is one year.
2. Equipment
To perform the checkout procedures described below, you must have the following:
o
A HP 8920 Communications Service Monitor or equivalent to transmit and receive over the
programmed frequencies.
o
An AT-150 or equivalent broad band antenna.
o
Miscellaneous cables and adapters.
o
A handset interfaced to the FLEXCOMM II system.
o
Four wire Ohmmeter.
NOTE: Calibration or internal LRU adjustments are only required on failure condition of the equipment under
test.
3. Antenna Verification
The bonding of the antenna and the radio chassis to the airframe should be verified to have an impedance of
less than 0.1 Ohm. The VSWR of the combined antenna and coax cable should be measured at the connector
to the radio. The VSWR should be no more than the maximum specified antenna VSWR in the operating
frequency band of the radio.
Note: On FLEXCOMM II systems with tuned antennas, power must be applied and the C-5000/RT-5000 must
be tuned to the frequency of measurement to program the antenna tuner to that frequency. Antenna VSWR is
valid only for those frequencies tuned. The frequencies chosen should be representative of the bands used for
normal operation.
4. Transmitter Verification
A. Select the manual data entry page.
B. Set the receive frequency to the desired frequency.
C. Set the modulation mode to AM
D. Set the bandwidth to standard.
E. Set the transmit frequency to the desired test frequency.
