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RF-7000E Operations Manual
Chapter 6. Maintenance and Troubleshooting
— 63
Problem
Cause
Solution
Repeater fails
overnight and
then restarts the
next day
(Solar Powered)
Improper PV Charging
Check the PV array for damage, obstructions or dirt.
PV Array wired to wrong
voltage
Check the PV open circuit voltage, V
oc
.
Typically the V
oc
will be 1.5 to 2 x the battery nominal
voltage. If V
oc
is more than 3 x the battery nominal
voltage and PWM
18
type PV controllers are used, the
array is mis-wired.
V
oc
may be greater only if MPPT
19
type PV controllers
are used.
Alarm Conditions
Check for alarm conditions and resolve, if necessary.
Battery capacity low
Batteries may be worn out or undersized, replace and
correct as necessary.
Prolonged storms
Storms or series of storms can reduce battery
recharging for days. Batteries may be fully discharged
causing the system to fail. Re-evaluate the power
source capacity, increase the PV array or add wind
turbine generators, increase the battery plant Ah
capacity.
Low RF Output
- or
–
No RF Output
Amplifier power not set
Set the amplifier output power level per radio
modulation.
Antennas Oriented or
Polarized Incorrectly
Check antenna orientation and re-align, if necessary.
Confirm the correct polarizations are used.
Alarm Conditions
Check for alarm conditions and resolve, if necessary.
Amplifier Failure
Replace the linear amplifier.
Terminal radio OFF
Confirm the terminal radio is transmitting.
Improper gain setting
Check gains and re-set, if necessary.
RF Output
cannot be set
Input level LOW
Low input level can be normal, refer to path
calculations for expected levels.
Confirm the terminal radio is transmitting.
Confirm frequencies and polarizations match.
Amplifier low gain failure
Damage to the amplifier can cause low gain which in
turn will reduce the available RF output power.
Replace the linear amplifier.
No Receive
Signals at
both ends
Problem Common to both
directions.
Check items in common with both directions of
transmission. Antennas, Feedlines, Site Power or
Multiple Failures.
Check Feedline connections; confirm correct antenna
port to antenna direction. Feedline reversal will result
in no signals at the ends and input to the repeater
amplifiers due to the bandpass channel filters.
Antennas Oriented or
Polarized Incorrectly
Check antenna orientation and re-align, if necessary.
Confirm the correct polarizations are used.
18
PWM: Pulse Width Modulator. PV Controller type that uses a rapid switch to reduce the average
charging current when batteries are fully charged. PV Array V
oc
should be 1.25 to 2.0 x the
nominal battery voltage. Higher Voc can indicate the array is mis-wired (series instead of
parallel) resulting in less charging current and power.
19
MPPT: Maximum Power Point Tracking. PV controller type includes a DC/DC converter to
“step down” higher voltage PV arrays. Maximum V
oc
is limited to the maximum rating of the
MPPT controller, typically 150 to 200 VDC.