Users Manual

126 MDS™ Master Station MDS 05-6399A01, Rev. G
The manual override toggle switch is locking, and must be pulled out to change positions. Switch
functions are as follows:
- Up —Radio A;
- Down — Radio B;
- Center — Automatic.
Once a new Radio Module is installed, the Select Switch should be returned to the Center (Auto-
matic) position for redundant operation.
A newly installed Radio Modules may require firmware reprogramming
and configuration update from the Platform Manager. Green alarm and
power LEDs on the Radio Module will alternate quickly during this process. Allow up to 5
minutes for the synchronization process to complete.
Internal Duplexer Tray
The duplexer tray can be removed by first removing two screws on the top of the chassis holding
the tray in place. Save these screws. Disconnect all cabling to both the faceplate of the duplexer
and on the back of the unit. Once cabling and screws have been removed, push on the connectors
on the back of the unit to free the tray from the chassis and then slide out the front. To install a
new tray, slide the tray in allowing the connectors to push through the back of the chassis. Use
the same screws to secure the front of the tray to the chassis and then reconnect cabling being
careful to connect TX and RX cables from the Alarm Module to the correct faceplate connec-
tions on the Duplexer Tray.
400 MHz Notch-Type Duplexers
You can generally change the radio’s transmit frequency up to 100 kHz without re-tuning the du-
plexer. The duplexers shown in Figure 8-1. 400 MHz Notch Duplexer can be aligned in the field
by experienced technicians using high-quality test equipment. For assistance, contact GE MDS
Technical Support for additional details about tuning.
Figure 8-1. 400 MHz Notch Duplexer
(Adjustment generally not required for transmit changes up to 100 kHz)
Duplexer alignment is a sophisticated procedure and a duplexer can be
easily damaged if not handled carefully. It is highly recommended that
you return duplexers needing realignment to GE MDS, or the original duplexer manu-
facturer, for alignment. In some cases, it may be more economical to replace the unit