Technical Manual

D C U M a i n t e n a n c e a n d O p e r a t i o n M a n u a l 53
APPENDIX
A
TESTING THE DCU
This section lists a variety of different tests. Select the test(s) appropriate for your
situation. Every visit does not require that every test be conducted.
DCU Antenna Pattern Test
If the DCU has been found to be able to reach some locations, but not reach others,
additional testing of the DCU antenna pattern may be necessary.
This test is used to measure the effect that metal near the antenna may have on the
omnidirectional pattern expected from the installation. (Or alternatively, the
DCU’s ability to reach meters at the base of the water tower, around the corner of a
building, or behind a mountain range could be tested.)
Tools Required (in addition to safety equipment):
• A laptop (or tablet) computer equipped with a cell card
• A signal analyzer which has a power meter capability
• A signal generator which can produce a carrier wave at 460 MHz with 2W
continuous output
• A vehicle to travel to distant locations (optional)
Baseline Data
1. The RF sweep tests should be conducted first to ensure any nearby metal is
not causing undue signal reflection.
2. Disconnect the RF coaxial cables which run up to the antennae.
3. Configure a calibrated, handheld spectrum analyzer to operate in power
meter mode and connect it to the Port 1 antenna output.
4. Transmit a command at the DCU and confirm that it provides 2.00 W of
output power into the antenna coax. Record your results, including the
time, date, and location.
5. Disconnect the RF power meter from the DCU.