Comtech EF Data LTT1450G User Manual
Page 15
LTT1450G Ku-Band Loop Test Translator
Installation
TM063 - Rev. 1
Page 2-3
A single 15 Vdc, 25-watt power supply provides the current to run the translator. The system is designed
to minimize power consumption.
The following section provides a description of the various signals that are present on each assembly:
2.5.1 Ku-Band PLO
The Ku-Band PLO (AS/5003B) is a Four-Band, Microstrip dual-loop phase-locked oscillator. The
primary loop of the PLO runs at either 1.75, 2.30, 2.55, or 3.05 GHz with a 25 MHz internal reference.
Signals in and out of the PLO include the following:
5.0 MHz Ref In
A 5.0 MHz reference is routed into the PLO module via this SMB connector. This signal is a
CMOS level.
+15 Vdc - This pin is the primary power input pin to the PLO module.
VT25-C
The VT25-C signal is the phase lock loop voltage from the 25 MHz phase-lock loop in the PLO.
The PLO contains a 25 MHz VCXO that drives the sampling phase detector of the primary loop
in the dual loop system. This signal is routed to the analog input of the microcontroller where it is
monitored for faults. This signal is also hard wired to the fault connector on the rear of the
chassis. A valid range for this signal is 1 to 7.8 Vdc.
VTPRI-C
VTPRI-C is the phase lock loop voltage of the PLO. This signal is routed to the analog input of
the microcontroller where it is monitored for faults. This signal is also hard wired to the fault
connector on the rear of the chassis. A valid range for this signal is 1 to 3.9 Vdc.
2.5.2 Ku-Band Converter Module
The Ku-Band Converter module is a microwave integrated assembly that contains the filters, mixer, and
voltage controlled attenuator. Signals in and out of this module include the following:
LO Input High-Band
The LO input is routed from the Ku-Band PLO module via semi-rigid cable. The 1.75 or 2.30
GHz CW signal is applied to the LO port at +8 dBm.
LO Input Low-Band
The LO input is routed from the Ku-Band PLO module via semi-rigid cable. The 2.55 or 3.05
GHz CW signal is applied to the LO port at +8.0 dBm.
RF Monitor Port