Nautel XR6, Preinstallation Manual

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XR6/XR3 Pre-installation Manual Other considerations
Page 7-2 Issue 3.0 2009-07-15
Installing an external RF drive source
1. If the RF drive for one or both exciters is to be applied from an external source, connect its
wiring as follows:
– Route RF drive coaxial cable through a cable entry hole in the cabinet and through the
ferrite toroid, to the vicinity of the remote interface PWB.
– Cut the RF drive coaxial cable to length, terminate it with a coaxial BNC connector and
connect it to the remote interface PWB’s EXT RF connector (J6).
2. Configure either (or both) exciter RF synthesizer(s) to operate on Ext RF drive by setting the
E4 jumper(s) to 1-2.
External 10 MHz frequency reference
You can apply an externally generated 10 MHz signal (such as a GPS clock signal) for use as the
reference frequency for the RF drive (carrier frequency) to the 10 MHz REFERENCE INPUT BNC
connector J2 on each RF synthesizer PWB.
1. The external 10 MHz frequency reference (one for each RF synthesizer PWB) must:
– remain stable at 10 MHz within ± 20 Hz
– have a peak-to-peak amplitude of between 2.2 V and 8.0 V (sine wave or square wave)
– be spectrally pure, since spurs may pass through to the transmitter output.
2. Configure each RF synthesizer PWB by setting E2 to 1-2 and E1 to 1-2.