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9
Qualifier System Installation Verification
1.
Power-on the VMD and wait a few seconds for it to initialize.
2.
On the HHD, connect a
≈
2 inch stub antenna to the BNC connector.
(Example: Use a straightened paperclip inserted into a BNC-to-F adapter.)
Make sure the HHD batteries are fresh.
3.
Stand about 10 feet from the vehicle and hold the
HHD with a vertical orientation of the stub antenna.
4.
Power on the HHD and then press the Button.
5.
The VMD orange Receive indicator flashes once
and then the yellow Transmit indicator comes on for
a moment.
6.
The HHD displays
‘ - - dB’
briefly and then shows a
reading between 25 and 80 dB.
Note:
If the HHD shows
‘> 80 dB’
and the
‘PASSFAIL’
label, check the Dual Band Antenna
connection and repeat the ‘Test the VMD Installa-
tion’ procedure.
7.
Set the HHD Threshold to a value less than the
displayed reading.
8.
Repeat the test and note that
PASS
is displayed.
9.
Set the HHD Threshold to a value greater than the
displayed reading.
10. Repeat the test and note that
FAIL
is displayed.
11. Set the HHD Threshold Level to 80 dB.
12. Repeat the test and note that neither PASS nor FAIL is displayed.
13. Reset the HHD Threshold to a value for system test operation.
Troubleshooting Notes:
If the trigger signal from the HHD is marginal, the VMD orange Receive indicator
flashes several times and the yellow Transmit indicator does not come on.
If the VMD is triggered by the HHD and the orange Receive indicator flashes once
(as normal) but the yellow Transmit indicator does not come on, there is a prob-
lem with the antenna or the internal transmitter section of the VMD.
If the TEST button on the VMD is pressed momentarily and the yellow Transmit
indicator does not come on, there is a problem with the antenna or the internal
transmitter section of the VMD.
The reliability of the HHD triggering the VMD may be reduced in these test loca-
tion scenarios:
•
The elevation of the HHD test location is significantly lower than the VMD
vehicle antenna.
•
The residence under test, located between the HHD and the VMD vehicle,
significantly blocks or absorbs the HHD trigger signal.
Initial Power On
Measurement in Process
