Kirisun TR850, Руководство по обслуживанию

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TR850 Service Manual
(VHF is 84.35~103.35MHz and 103.35~122.35MHz) respectively, and the switch of VCO is controlled by
the RXVCOSELECT signal. VCO employs three point capacitance oscillation circuit. The VCO that covers
the band of 348.35~383.35MHz (VHF is 84.35~103.35MHz) is composed of D1006~D1009
、
L1017
、
Q1011 and some other components, while while the VCO covers the band of 383.35~418.35MHz (VHF is
103.35~122.35MHz) is composed of D1002~D1005
、
L1016
、
Q1009 and some other components.
3.2. GPS Ciruit
Figure 3-5 GPS Schematic Diagram
As Figure 3-5 shows, the repeater baseband board includes the GPS module (U9) and the GPS antenna
interface J8(SMA). The corresponding equipment box is also assembled with a GPS antenna interface
which supports the outdoor active antenna. The GPS module integrates a baseband processor, LNA and
SAW. The antenna receives the 1575.42MHz GPS signal, after the inner amplification and filter process, it
will be sent to the baseband section for further calculating, to get the geographical location and time
information of the equipment. The output data information will be sent to processor (U4). Meanwhile, the
GPS module hardware will provide the one-pulse-per-second signal (1PPS) for OMAP and FPGA
respectively.
8