R.V.R. Elettronica HC4, User Manual

Page: 32 / 72

HC4
28 / 34 User Manual Rev. 1.0L - 01/04/02
The coupler section includes resistive terminations mounted on the heat sink that
dissipate possible unbalancement power due to non-optimal adjustment, different
performances of the amplifiers, or any malfunctioning in the transmitter.
9.4 Remote Card
This board is installed on the right side of the device. It is controlled by the CPU,
and its function is to cut the power in the auxiliary mains plug in case of alarms.
9.5 CPU
This section implements all the software functions described in the previous part
of the manual (measurement, protection, controls, data visualization,
communications). The analog circuitry normalizes and measures the different
parameters that are monitored by the device.
The CPU board interfaces itself with external devices using a special telemetry
connector, a RS232 serial port and a I
2
C port.
9.6 Telemetry board
This device is designed to give to the user a set of dry contacts connected to the
working status of the machine. The contacts can be configured as Normally Open
or Normally Closed and are triggered by the user settable thresholds, and by
LOC/REM, WAIT, FAULT, ON, OFF, INHIBIT.
The analog signals generated by the hybrid coupler are available on a DB25
connector hosted on the telemetry board.
9.7 Adjustment
The hybrid coupler is factory-adjusted so that the transmitter it is included in will
work satisfyingly works over the whole FM band.
Cases may happen, that it is necessary to perform the RF adjustment of the HC4,
for example if the RF interconnection cables with the amplifiers have been sustituted
with other of slightly different characteristics or length, or if it is desirable to optimize
the transmitter’s performances on a certain frequency.
WARNING: we suggest not to perform the operations described in this chapter
to personnel lacking proper instrumentation and deep knowledge of the
device and its working principles.
9.7.1 Capacitors on the splitter circuit
1) Remove the upper cover of the coupler
2) Switch on the transmitter, having the exciter set on the working frequency