Replacing The Dual Circulator/Isolator Modules - Motorola ASTRO 25 GTR 8000 Manual

5 Using a T20 bit, remove the transmit filter from the tray by removing the screws that attach it to
the tray.
6 Install the new transmit filter in the tray as follows:
a Place the new transmit filter in the tray in the same location and orientation as the module
that you removed.
b Using a T20 bit, secure the replacement transmit filter to the tray using the screws removed
in step 5.
7 Re-install the transmit filter tray in the rack as follows:
a Slide the tray in the front of the rack.
b Using a T30 bit, secure the tray to the rack with the two screws removed in step 4b.
c Reconnect the Tx input, Antenna output, and ground cables to the transmit filter.
8 Set the rocker switches on the front of the power supplies to the ON (I) position.
9 Place each base radio in Normal Mode, as follows:
a From the menu, select Service → Test and Measurement Screen.
b Click Change to Normal Mode.
c At the confirmation screen, click OK.
The base radio halts activity in the current mode and switches operation to the requested
mode.
9.12

Replacing the Dual Circulator/Isolator Modules

For a GTR 8000 Base Radio, the following Radio Frequency Distribution System (RFDS) modules are
assembled in a tray:
• External Dual Circulator/Isolator
• Circulator Load (a module connected directly to the External Dual Circulator module)
• Low Pass/Harmonic Filter
Figure 110: External Dual Circulator/Isolator Tray (700/800 MHz) on page 254
External Dual Circulator/Isolator Tray (UHF) on page 255
Chapter 9: GTR 8000 Base Radio FRU Procedures
and
show these modules installed on a tray.
MN003286A01-E
Figure 111:
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