R
R
F
F
-
-
7
7
0
0
0
0
0
0
E
E
M
M
i
i
c
c
r
r
o
o
w
w
a
a
v
v
e
e
R
R
F
F
R
R
e
e
p
p
e
e
a
a
t
t
e
e
r
r
— Chapter 3. Mounting the Antennas
RF-7000E Operations Manual
44
Alternative Fine Alignment using repeater power measurements
9.
This method requires the RF-7000E repeater to be installed, connected to the antenna feedlines
and powered up. See Chapter 4 for repeater installation details.
10.
Before antenna orientation begins, the amplifiers must be operating in their full gain mode (out of
AGC/ALC range). The setting of the AGC/ALC along with a high input level (greater than [desired
output power level in dBm - max. linear gain in dB] ) may cause the normal action of the
AGC/ALC circuit to mask changes in power due to azimuth and elevation sweeping of the
antennas. The output power of an amplifier will increase in level as the input level is increased to
the point where the AGC/ALC has been set (eg. +18 dBm). Further increases in input level will
be absorbed in the AGC/ALC circuit. Use the amplifier power monitor point as a signal strength
indicator. The input level can be reduced temporarily by inserting a fixed or variable attenuator
pad ahead of the amplifier. The attenuation required will range from 0 to 30 dB depending on
desired power and input signal level. Remove the input semi-rigid coax cable and place the
attenuator in series with the coax or use flexible coax as required for fit. Reduce the input level
until the output power drops below the desired power level. If during antenna orientation, the
power rises to the desired power level, reduce the input level again and then continue with
antenna orientation.
11.
Alternatively, the amplifier's maximum gain can be reduced such that the system is out of
AGC/ALC for antenna alignment. Gain adjustment is provided by a potentiometer just below the
AGC/ALC adjustment. Be sure to return the potentiometers to their normal positions after
antennas are aligned. (Usually at the maximum linear position.)
12.
Connect the power meter or spectrum analyzer to the f1 amplifier, A1, RF MON port. With a
signal transmitted from the A terminal, position the antenna A for a maximum power reading on
the meter or analyzer. After antenna A is aligned, remove any temporarily installed input
attenuators. Re-set the power level with the AGC/ALC adjustment if needed. The AGC/ALC
adjustment is located near the output end of each amplifier, see Figure 3. Use a screw driver or
tuning tool to adjust the AGC/ALC potentiometer CW to reduce the power setting or CCW to
increase the AGC/ALC set point. Log the power reading to fulfill FCC requirements. Remove the
meter from the f1 Amplifier RF MON to the f2 Amplifier RF MON.
13.
With a signal transmitted from the B terminal, position the antenna B for a maximum power
reading on the meter or analyzer. After antenna B is aligned, remove any temporarily installed
input attenuators. Set the power level with the AGC/ALC adjustment if needed. Log the power
reading to fulfill regulatory and administrative requirements. Measure and log the power at any
additional amplifier directional couplers so equipped (f3, f4...). Remove the meter.
14.
After the antenna orientation has been completed at both terminals and the repeater, AGC/RSL
readings should be taken at the end terminals and logged for reference. Provide the records to
the end customer or controlling authority.