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16 PERFORMANCE
TESTS
This section includes procedures to verify the performance of the radio installation. Testing requires a
wattmeter to measure RF power. There are three procedures in this section:
•
Changing Operating Modes
•
Testing into a Dummy Load
•
Testing with the Antenna
The normal operating mode of the radio for voice or data communications with the CH-103 and CH-
103PA Control Head is the OpenSky Trunking Protocol (OTP) mode. However, the radio must be
operating in a test mode in OTP for testing the antenna connection. The reason for this is OTP employs a
Time Division Multiple Access (TDMA) protocol in which power does not transmit at a 100% duty cycle.
In this case, a measurement error would result in transmission power level, as indicated on a typical
power meter that reads average or RMS power instead of peak power. The test mode allows for 100%
duty-cycle transmissions, thus not forcing the consideration of duty cycle factors.
NOTE
The accuracy of test results depends upon a DC power source in the range of 13.8 to
16 volts dc, with a current capacity of greater than 8 amps. Make sure the vehicle’s
battery is fully charged by running the engine for a few minutes before the test, and
keep the engine running during the test procedures.
The vehicle’s location should be
well ventilated so exhaust fumes from the engine do not cause harm!
Alternatively,
instead of running the vehicle’s engine for an extended period of time, a 12-volt
vehicle battery charger with a current capacity of at least 15 amps can be connected to
the vehicle’s battery. If using a battery charger,
observe polarity
when making the
connections to the battery.
CAUTION
If a vehicle equipped with this radio requires jump-starting, the installation’s main
ATC fuse should be removed from the holder prior to jump-starting. Doing so will
prevent damage to the radio system.
NOTE
Prior to installation, the radio’s power level should be configured appropriately. The
wide range of power levels indicated in the following procedures takes into account
such things as: customer’s requirements; measurement errors, especially to include
uncalibrated equipment; cabling losses; and voltage and temperature variations. By no
means should the result from Performance Testing in this section be construed as the
exact value of power level output from the radio, as that value is set and more
accurately measured in the factory. The values obtained in these test procedures
determine a successful installation only.