Glenayre Electronics Inc. GL-T8600-CN Manual Do Utilizador
DSP Exciter
Glenayre Document Number: 9110.00172
THEORY OF OPERATION
Issue 1, Rev. I: 01/15/97
Page: 6-16
Copyright © 1997 Glenayre
Print Date: 02/19/97
6.6.2.3.5
Synthesizer-2
Synthesizer-2 controls VCO-2 carrier frequency by means of a phase-locked loop (PLL).
PLL inputs to synthesizer-2 are a carrier and a phase reference. The reference is a ten-MHz
carrier supplied by the ten-MHz reference circuit. The carrier is the VCO-2 output. The
PLL output from synthesizer-2 is a dc control voltage. This voltage, set to cause VCO-2 to
lock phases with the reference, is applied to the VCO-2 control input.
PLL inputs to synthesizer-2 are a carrier and a phase reference. The reference is a ten-MHz
carrier supplied by the ten-MHz reference circuit. The carrier is the VCO-2 output. The
PLL output from synthesizer-2 is a dc control voltage. This voltage, set to cause VCO-2 to
lock phases with the reference, is applied to the VCO-2 control input.
Synthesizer-2 also performs all communications between the RF stage circuit and the MCU
control circuit. A control input to synthesizer-2 specifies VCO-2 carrier frequency. This
data is received over a serial data link when the exciter is booting or changing channels.
Status outputs from synthesizer-2 are a lock fault and a VCO2 level. The lock fault
indicates loss of the carrier/reference phase lock. VCO2 level is the VCO-2 control voltage.
control circuit. A control input to synthesizer-2 specifies VCO-2 carrier frequency. This
data is received over a serial data link when the exciter is booting or changing channels.
Status outputs from synthesizer-2 are a lock fault and a VCO2 level. The lock fault
indicates loss of the carrier/reference phase lock. VCO2 level is the VCO-2 control voltage.
6.7
Voltage Regulator Circuit
(center, toward bottom)
in the following discussion. The exciter receives 26-volt operating power through terminal
board TB1. The dc power indicator on the exciter front panel is connected to this input. This
voltage is supplied to a 26-volt bus and is monitored by the MCU. An intermediate
regulator reduces the 26 volts to 16.5 volts, which is supplied to the two final regulators.
One regulator generates 13.5 volts, which is supplied to a 13.5-volt bus and monitored by
the MCU. The other regulator generates 5 volts, which is supplied to a five-volt bus and
monitored by the MCU.
board TB1. The dc power indicator on the exciter front panel is connected to this input. This
voltage is supplied to a 26-volt bus and is monitored by the MCU. An intermediate
regulator reduces the 26 volts to 16.5 volts, which is supplied to the two final regulators.
One regulator generates 13.5 volts, which is supplied to a 13.5-volt bus and monitored by
the MCU. The other regulator generates 5 volts, which is supplied to a five-volt bus and
monitored by the MCU.