5.3 Aligning ASTRO Simulcast (Trunked Operation)
See Base Radio Service Help > Service Screens > Alignment Screens in the
CSS Online Help
for the alignment
procedures.
Some batteries do not require equalization. See the battery manufacturer recommendations.
5.3 Aligning ASTRO Simulcast (Trunked Operation)
ASTRO
®
25 Simulcast Alignment is used to enter a Launch Time Offset value (range 0.0 to 1000.0 usec), store the
value in the base radio, and initiate a simulcast test pattern.
See Base Radio Service Help > Service Screens > Alignment Screens in the
CSS Online Help
for the alignment
procedures.
5.4 Aligning ASTRO/Analog Simulcast (Conventional
Operation)
In an ASTRO
®
25 simulcast subsystem, all station transmitters are synchronized to a 1 pulse per second (pps) signal
from a global positioning satellite (GPS) receiver. The 1 pps signal provides a common time reference for each of
the transmitters. The ASTRO
®
25 signaling information arriving at the station transmitter includes timestamps
that specify the transmit offset delay for the voice and data transmissions.
To allow the user to adjust the overlap coverage areas, the ASTRO/Analog Alignment screen is provided to allow
the user to specify a launch time offset value, with a 0.1 μs resolution. This value is added to the arriving launch
time value to provide an adjusted launch time. The specified ASTRO
®
25 simulcast transmit offset delay value
applies only to ASTRO
®
25 simulcast subsystems and is considered optional. The default offset value is 0 (zero),
causing no adjustment to the launch time specified by the arriving timestamp value.
For Analog Simulcast, the Transmit Offset Delay merely delays the Analog Simulcast Audio to provide the
adjustment in the overlap coverage areas.
See Base Radio Service Help > Service Screens > Alignment Screens in the
CSS Online Help
for the alignment
procedures.
5.5 Aligning Carrier Squelch
A Carrier Squelch (CSQ) Alignment is typically performed at an RF level which corresponds to 12 dB SINAD, or
an RF level which corresponds to 20 dB quieting, or any other RF level selected by the user.
The CSQ Alignment screen facilitates the measurement of 12 dB SINAD for the base radio under test by allowing
the Rx Qualifiers to be set to Open. When the Rx Qualifiers are set to Open, receive audio is gated to the WL2
wireline port or to the speaker, regardless of the RF input level. The preferred SINAD measurement port is the WL2
wireline port; however, the speaker can also be used.
When measuring SINAD, the pre-emphasis and High Pass filters are set as they would be for analog voice operation.
Since the channel characteristics are different, this procedure allows for CSQ Alignment to be done for both 12.5
kHz and 25 kHz channel bandwidth. If the station is configured for only one channel bandwidth, there is no need to
perform a CSQ Alignment for the other bandwidth.
6871022P86-A - November 2012
5-3
Summary of Contents for GTR 8000
Page 2: ......
Page 4: ......
Page 6: ......
Page 14: ......
Page 18: ......
Page 22: ......
Page 26: ......
Page 60: ......
Page 177: ...5 8 1 3 VHF Tuning Procedure Figure 5 1 Preselector Tuning VHF 6871022P86 A November 2012 5 7 ...
Page 181: ...5 8 2 3 UHF Tuning Procedure Figure 5 2 Preselect Tuning UHF 6871022P86 A November 2012 5 11 ...
Page 230: ......
Page 234: ......
Page 244: ......
Page 286: ......
Page 300: ......
Page 338: ......