Sennheiser SI 29-5 User Manual

SI 29-5

IR Audio Transmission Technology | Modulators/Radiators

General Description

The SI 29-5 is a 5-channel modulator. Its audio channels can be programmed to any of the 32 narrow-band channels, and monitoring is no problem due to integrated IR transmission diodes. The modulator is easy to program and features clear LED displays for monitoring all modulator functions.

Tec hnic al Da t a

Modulation .................................................narrow-band FM

Nominal/peak deviation...........................± 6 kHz/± 7 kHz

Amplitude limitation..... limiting amplifier (max. 30 dB)

Deviation display .................peak/5 dB/3 dB/ 1 dB/0 dB/

–1 dB/–3 dB/–5 dB/–7 dB/ –10 dB/–15 dB/–20 dB

Audio channels ..................................................................five

Channel frequencies .................................... 55 – 1,335 kHz

AF inputs I .........................................transformer-balanced

XLR-3F sockets, optional 12 V phantom powering

AF input II..................................... 25-pole sub-D socket, in

parallel with AF inputs I, optional 12 V phantom powering

Input sensitivity................... 50 mV – 1.5 V (line) optional

0.5 mV – 30 mV (microphone)

AF frequency response................................50 – 12,000 Hz

THD ................................................................................< 0.5 %

AF signal-to-noise ratio................................. > 70 dB (A)

RF outputs................................ 2 x BNC, short-circuit-proof

RF cascading sockets .................................................2 x BNC

Output impedance...........................................................50 Ω

Features

Modulator with up to five narrow-band audio channels

Each audio channel can be programmed to any of the 32 carrier frequencies

Several units can be cascaded to make systems of up to 32 channels

Integrated IR monitoring diodes

19“ (1 U) housing

Delivery includes: 1 x SI 29-5 modulator

Suppression of harmonics........................................ > 60 dB

Power supply ......... 12 V AC, via NT 29 plug-in mains unit

Power consumption .............................................max. 17 W

Dimensions .............................approx. 485 x 45 x 340 mm

Weight .................................................................approx. 4 kg

Cat. No. 003986

rms

Recommended Accessories

Plug-in mains unit

NT 29 European version Cat. No. 004002 NT 29-120 USA version Cat. No. 004003 NT 29-UK UK version Cat. No. 004004

BNC-BNC co-axial cable

GZA 1019 A 1 (1 m) Cat. No. 002324 GZA 1019 A 5 (5 m) Cat. No. 002325 GZA 1019 A 10 (10 m) Cat. No. 002326

GZV 1019 A BNC coupler Cat. No. 002368

SI 29-5

IR Audio Transmission Technology | Modulators/Radiators

The SI 29-5 is a multi-channel modulator in a compact 19“ (1U) housing. Five audio

340 mm

485 mm

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 3 4 56

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

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 available twice. You have a choice of either feeding the audio signals to separate XLR-3F

45 mm

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 simultaneously 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 standardised carrier frequencies to the selected audio channel. To avoid accidental reprogramming, you need to hold the CHANNEL key for about 1.5 seconds af ter you have released the +/– but tons i n 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 of f unused channels will increase your radiators’ output power as the number of channels 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 settings are stored in an EEPROM. As a result, the data remain stored even if the modulator 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.

SI 29-5 back panel