User Manual
AS4000 Survey Tool
605-0000-429
DLP-004
Issue 1.6. Date 1/9/99
Page 2 of 4
3. Power Control Recording
1. The voltage measured is a relative indication of the transmit power level: The lower the
voltage the higher the output power level. This is only valid when the link LED is lit - only
possible with TX enabled.
2. Check the label on the CRU to get an indication of the transmit signal strength from the
characterised readings to ensure that the margins are consistent with the receive fade
margins.
+21
+15
+11
TRANSMIT SIGNAL
STRENGTH /dBm
PC DIGITAL
VOLTMETER
READING
Figure 14. Label Detail: Transmit Power Control
4. CRU Panning
1. Ensure that the steps outlined in DLP-003 are completed before commencing this DLP.
2. Observe the AGC meter on the test box and read the DC voltage on the meter. The voltage
measured is a relative indication of the received signal strength; The lower the voltage the
weaker the RX signal, and vice versa. If no link double check that the programming code is
the correct one and that it has been entered correctly
3. Whilst observing the voltage on the meter, pan the CRU through the peak point, then pan
back to it. The CRU is panned by releasing the section clamping screw from the lowest
extending section of the mast and twisting the extended sections by hand through the panning
range. Rubber gloves should be worn when rotating mast to avoid contact with the mast
lubricating grease. When the optimum position has been reached the section should be
locked using the section clamping screw.
4. If the AGC value indicates less than 10dB fade margin (from the values shown on the
testhead CRU), then another position must be found.
If AGC value indicates greater than 10dB fade margin switch on the transmitter by setting
the TX Switch to the TX enabled position. Note: The CRU will automatically reset and
begin the link acquisition process.
5. After approximately 30 seconds the AGC meter should return to the same value as prior to
switching on the transmitter. Within 5mins (typically 1.5mins ) the Link LED lights up to
show that a link has been acquired.
6. Record The AGC and PC voltages and estimate the angle between CRU and wall it is to be
mounted on. The assessment of angle may be assisted by the use of the Angle Template
described in Appendix C.