Glenayre Electronics Inc. GL-T8311SA Manual Do Utilizador
Glenayre Document Number: 9110.00166
GL-T8xx1 Transmitter System
Revision K: 08/30/99
DESCRIPTION
t523.
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Copyright © 1999 Glenayre
Page: 3-7
The exciter provides up to 0.5 watt of RF drive to the PA. A power-reference signal from
the PA is fed back to the exciter, via the metering board, to allow control and monitoring of
output power.
the PA is fed back to the exciter, via the metering board, to allow control and monitoring of
output power.
3.3.3.2
Power Amplifier RF Compartment
The PA performs amplification of the RF signal generated by the exciter. The PA amplifies
a nominal 0.5-watt signal to rated power for application to the antenna system. Monitoring
circuitry is on the metering board in the rear compartment of the PA chassis.
a nominal 0.5-watt signal to rated power for application to the antenna system. Monitoring
circuitry is on the metering board in the rear compartment of the PA chassis.
3.3.3.3
Metering Board
The metering board provides a rectified dc sample of the PA output to the exciter; the
exciter, in turn, generates a power-control voltage which maintains PA power at the desired
level.
exciter, in turn, generates a power-control voltage which maintains PA power at the desired
level.
The metering board also returns operational parameters of the PA, which information can
be read by the transmitter controller and the VDT.
be read by the transmitter controller and the VDT.
The metering board also serves as a distribution point for dc power for other assemblies
within the transmitter chassis.
within the transmitter chassis.
3.3.3.4
Power Supply
Because different power supplies can be used, refer to the appropriate power supply manual
for details.
for details.
3.3.3.4.1
Ac-Powered Sites
The standard ac power supply takes ac input, converts it, rectifies and filters it, and supplies
dc output to all racked equipment. Each dc circuit is individually fused on the front of the
supply. A circuit breaker on the front of the supply doubles as a transmitter power on/off
switch.
dc output to all racked equipment. Each dc circuit is individually fused on the front of the
supply. A circuit breaker on the front of the supply doubles as a transmitter power on/off
switch.
3.3.3.4.2
Dc-Powered Sites
Dc-only sites typically have a dc breaker / fuse panel mounted for power control. An
external dc source should meet all pertinent specifications. A racked dc-to-dc converter
needs to have adequate cooling provisions so as not to overheat other racked equipment.
external dc source should meet all pertinent specifications. A racked dc-to-dc converter
needs to have adequate cooling provisions so as not to overheat other racked equipment.
3.3.4
Video Display Terminal
The VDT, though not part of the transmitter, is required for setup, local control, and local
monitoring of the transmitter. The VDT can be any laptop or desktop terminal with a
VT-100 type program. The VDT interfaces the transmitter through the connector on the
front of the exciter. The VDT software is menu-driven.
monitoring of the transmitter. The VDT can be any laptop or desktop terminal with a
VT-100 type program. The VDT interfaces the transmitter through the connector on the
front of the exciter. The VDT software is menu-driven.