EDACS REPEATERS
2-16
RF S/N
RF Path S/N level.
As the EDACS repeater re-transmits the signal from the transmitting radio, a S/N measurement
can be obtained from the RF path.
The RF path S/N test is used to measure the S/N level of the signal received and re-transmitted by
the repeater.
The test fails if the measured S/N level is below the prescribed level.
The Service Monitor is modulated with a 1 kHz signal at the nominal modulation level. The
Service Monitor then measures the S/N level of the modulated signal of the repeater.
Failure messages are:
*FAIL* ABORTED BY USER
User halted program before test was complete.
*FAIL* NO MODULATION
No modulation has been received from the
repeater.
*FAIL* UNSTABLE DEMOD
Demodulation was not within 5
%
after 3 readings or
1
%
after 10 readings.
Tx Frequency
Transmitter RF frequency
The Tx frequency test is used to determine the accuracy of the RF frequency generated by the
repeater on the current working channel. The test fails if the RF frequency is found to be outside
of the prescribed limits. The message
'*FAIL* OUT OF RANGE
' is displayed.
Other messages are:
*FAIL* ABORTED BY USER
User halted program before test was complete.
Tx Level
Transmitter RF power.
Measures the RF power output from the repeater.
Messages are:
*FAIL* ABORTED BY USER
User halted program before test was complete.
Tx SINAD
Transmitter SINAD.
The Tx SINAD test is used to measure the SINAD level of the modulated transmission from the
repeater.
The test fails if the measured SINAD level is below the prescribed level.
The Service Monitor AF generator frequency is set to 1 kHz and its level is adjusted until the
repeater generates the nominal modulation level. The Service Monitor then measures the Tx
SINAD of the modulated signal of the repeater.
Failure messages are:
*FAIL* ABORTED BY USER
User halted program before test was complete.
*FAIL* NO MODULATION
No modulation has been received from the
repeater.
*FAIL* UNSTABLE DEMOD
Demodulation was not within 5
%
after 3 readings or
1
%
after 10 readings.
