Advertisement
SI 29-5
IR Audio Transmission Technology |
Dimensions of the SI 29-5
1 2 3
4
5
6
7
1 LED display for indicating the audio channel (1 – 5)
2 LED display for indicating the transmission
channel (0 – 31)
3 IR transmitting diodes for monitoring the RF
output signal
4 LED bargraph for deviation display
5 Menu keys
6 five LEDs for indicating the audio inputs which
deliver their signal to the RF output
7 +/– keys
SI 29-5 front panel
1
2
1 BNC RF cascading socket for connecting
additional SI 29-5
2 Five XLR-3F audio inputs, transformer balanced
3 BNC RF cascading socket for connecting
additional SI 29-5
4 BNC RF outputs to radiators, short-circuit-proof
5 Socket for plug-in mains unit, connector is twist-
locked to the socket
6 25-pole sub-D socket for all audio inputs,
in parallel with the XLR-3 inputs
SI 29-5 back panel
340 mm
485 mm
3 4
5
6
Modulators/Radiators
The SI 29-5 is a multi-channel modulator in a compact 19" (1U) housing. Five audio
channels can be programmed to any of the 32 standardised narrow-band channels.
Using the cascading sockets at the back, up to seven SI 29-5 can be cascaded to
make a 32-channel system. The AF inputs at the back of the modulator are avail-
able twice. You have a choice of either feeding the audio signals to separate XLR-3F
sockets or to a 25-pole central sub-D connector for all inputs. Both input types are
connected in parallel and balanced by a transformer.
The modulator is programmed with the menu keys and the +/– buttons. By simul-
taneously pressing the INPUT key and either the + or – key, you can select the audio
channel to be transmitted. With CHANNEL, you can assign one of the 32 standard-
ised carrier frequencies to the selected audio channel. To avoid accidental repro-
gramming, you need to hold the CHANNEL key for about 1.5 seconds after you have
released the +/– buttons in order to make the modulator accept the new carrier
frequency. Beside channels 0 – 31 you can also choose the "OF" (off) position, which
switches the audio channel off. The corresponding LED will go out. Switching off
unused channels will increase your radiators' output power as the number of chan-
nels reduces the radiator coverage area accordingly.
The AF LEVEL key serves to adjust the sensitivity of the corresponding audio input.
You can adjust line signals between 50 mV and 3 V in 50 steps. All modulator set-
tings are stored in an EEPROM. As a result, the data remain stored even if the modu-
lator has been disconnected from the mains for a long period of time. With the help
of the two IR monitoring diodes, you can listen to the RF signal with a suitable IR
receiver – even when the radiators have not yet been connected or do not cover the
technicians' area.
You can connect two chains of IR radiators to the RF outputs of the SI 29-5. The BNC
sockets are short-circuit-proof. By means of the RF cascading sockets, the summing
signals of several SI 29-5 can be mixed. The two sockets are connected in parallel
and can be used both as an input and as an output.
For example, to set up a 15-channel system as shown in the drawing at the bottom
left, simply connect the modulators (no particular order necessary) with BNC-BNC
cables. The signal of all modulators will be available at any of the RF output sockets,
and you can operate the devices just as before. When setting up multi-channel
systems, you have to pay special attention not to assign a carrier frequency twice.
Even if one channel only transmits the carrier, the transmission of the modulated
signal on the other channel will be disturbed.
Advertisement
