Nautel NX15, Operation And Maintenance Manual

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NX15/NX25 Operations and Maintenance Manual Description
Page 1-8 Issue 6.0 2019-01-31
Local and Remote Interfacing
A 17-inch, colour LCD screen along with the Single Board Computer mounted on the front of
the control cabinet provides an advanced user interface (AUI) for the transmitter. The AUI can
be controlled by touch screen and is also available via the Ethernet connection on the SBC,
through a web browser on any web-interfaced PC or handheld device. See “Using the AUI” on
page 2-2 for detailed information on AUI functionality. The SBC also accepts customer USB
connections for audio playlist functionality.
The remote interface PWB provides customer connections for the discrete wire remote I/O
interface, including digital remote inputs, digital remote outputs and analog outputs. The
Remote Interface PWB also provides push-button control of digital remote inputs and LED
indication of digital remote outputs that can be used as a backup control/monitor interface.
RF Power Stage
See electrical schematics
SD-4
,
SD-5
and
SD-6
. The RF power stage includes all of the
transmitter’s 5 kW RF power blocks. The NX15/NX25 contains 5 RF power blocks.
Each RF power block contains two RF power modules and associated relays, a fan tray, and
connections to the RF drive distribution PWB, PDM distribution PWB and rack interface
PWB. Each RF power module accepts RF drive from the RF drive distribution PWB through
the power module interface PWBs and PDM from the PDM distribution PWB. B+ and +15 V
dc voltages are applied to the RF power modules via the B+ distribution assembly, the rack
interface PWB and power module interface PWBs. +48 V dc voltage is applied to the fan trays
via the rack interface PWB. The output of each RF power module is applied to a primary
winding of a series combining transformer. The resultant combined output is applied to the RF
output network.
Each RF power module also:
• monitors the tachometer signals from the two fans on its associated fan tray - applied
through the power module interface PWBs - and will shut down if one of the fans fail.
• controls its associated RF relay on the power module interface PWB, ensuring the
relay is closed when the RF power module is disabled, allowing combiner current to
continue flowing in the primary of its associated combiner transformer.
• provides status information to the rack interface PWB over a serial bus connection.