Pag. 22
SIRIO 2000T
SIRIO 2000T
SIRIO 2000T
SIRIO 2000T
SIRIO 2000T
Electronic Broadcast Equipment
In case of unbalanced drive, input pin 2 shall be short-circuited with ground and shield on pin 1, while
the signal shall be available on pin 3. Higher impedance selection, in this case, will be 5 kohm instead of 10
kohm.
With balanced drivings signals, the connecting canles
to the audio source may be far longer than 100-m.
Mpx or an externally processed signal, usually an
unbalanced one, can be connected to the female BNC
connector, marked "MPX", which is internally parallel
wired to the "RIGHT" channel connector: for this
reason it is not possible to connect signals to these two
connectors at the same time. Higher impedance
position is 5 kohm in this case too.
If the distance exceeds several tens of metres, use
75-ohm (RG59) or 92-ohm (RG62) cables.
The auxiliary-channel connector is also of the
grounded BNC female type. Use 50-ohm (RG58) or
75-ohm (RG59) cables for the connection to the
driver. The same applies to the monitor
"MODULATION" output, if needed.
Pre-emphasis setting
Low frequency mono and stereo channel signals have to be adequately “pre-emphasised”. Standard
preemphasis time constant is 50 and 75µs, the former being usually factory pre-set. Check whether this is
correct for your country (it is usually correct for any European country and most of the Pacific and South
American areas). It is not correct for USA standards, which requires 75µs.
If above correction is needed, simply set it on the "mode" FCC frame of the transmitter menu, which
also includes mono/stereo operation and frequency. See appropriate section further ahead on in this manual.
LF input level range, setting and requirements
In the following paragraph we will refer to 0 dBm as the audio signal which produces 1mW on 600 ohm,
i.e. a
775 mVrms / 2200 mVpp sine.
Irrespective of the impedance and the non-sinus form of the signal,
we will continue to assume 0 dBm as a LF signal whose peak is + (or -) 1100 mV.
