Sennheiser SI 29-5 User manual

8
SI 29-5
Instructions for use

9




Putting the IR modulator into
operation/power supply The SI 29-5 infra-red modulator is powered via the NT 29 plug-in mains unit .
It is connected to the DC input socket by a special twist-lock connector.
The NT 29-5 mains unit is available in different versions, so that the SI 29-5
modulator can be used with the respective voltage of your country:
• NT-29-EU 230 V 50/60 Hz Cat. no. 04002
• NT 29-120 120 V 50/60 Hz Cat. no. 04003
• NT 29-UK 240 V 50/60 Hz Cat. no. 04004
AF inputs Five XLR input sockets for connection of five mono audio signal sources are
located at the back of the SI 29-5 infra-red modulator.
The inputs are balanced and floating.
In addition, all inputs are available at the 25-pin D-connector . For the
connection details of this connector please see the service manual.

10

쒅
쒆
Connecting IR radiators Connect the infra-red radiators to sockets . The SI 29-5 will modulate the
infra-red light which will then be radiated by the IR radiators.
You can connect a maximum of 50 radiators to the SI 29-5 modulator. You
can also use different radiators (mixed operation):
• SZI 20 Low power infra-red radiator for small rooms, cascadable
• SZI 1029 High power infra-red radiator, IR radiating power 5 W,
socket for connection of additional SZI 1029, SZI 1029-10
or SZI 20. Black or unpainted aluminium housing.
• SZI 1029-10 High power infra-red radiator, IR radiating power 10 W,
socket for connection of additional SZI 1029, SZI 1029-10
or SZI 20. Black housing.
씰N.B. Please also read the instructions for the IR radiators!
Avoid very long cable lengths because they lead to signal cancellation when
IR radiators are facing one another:
Wrong !
RIsk of
cancellation !
correct !

11

To make a larger system, you can combine several infra-red modulators. In
the largest possible system, a maximum of 32 transmission channels can be
used:
Number of modulators Maximum number of transmisson channels
15
210
315
420
525
630
732
N.B.:
Do not duplicate channel numbers!
Cascade the infra-red modulators with a BNC connection cable. Use the
cascading sockets (∑) for interconnecting. Since these sockets are internally
connected in parallel, it does not matter whether you choose the left or the right
socket .
Connecting several SI 29-5 modulators


12
Choosing the audio input By simultaneously pressing the buttons "INPUT" and "+" or "-", you start
the input search for sockets 1 - 5 at the back of the modulator.
With the "+" button you choose a higher input number.
Holding this button down initiates fast search, continually
cycling from the beginning.
With the "-" button you choose a lower input number.
Holding this button down initiates fast search, continually
cycling from the beginning.
When both buttons are released the selected input is stored. Now you have
to choose the infra-red transmission channel for the selected input.
Choosing the
IR transmission channel
Switching a channel off
By simultaneously pressing the buttons "CHANNEL" and "+" or "-" you start
the search for the infra-red transmission channel which is to be assigned to
the input.
To switch a channel off, search through the transmission channels as described
above. The OFF position is the next channel above "£ ¡" or below "ºº"
(depending which way you go). The display will indicate "ºF." instead of a
channel number and the corresponding LED will go off.
NB: It is important that any unused channels are switched off. Any
channel left on, but unused, will reduce the radiator coverage area accor-
dingly. (See the section on calculating the radiator coverage area in the user
manual supplied with the radiator).

13



Adjusting the AF level
Monitoring facility Two infra-red transmission diodes are located behind the display window
on the modulator front panel. They transmit the complete infra-red signal for
monitoring purposes. Thus you can check the selected transmission channel
with a suitable receiver (e.g. an HDI 1029 PLL). The transmission distance
of the IR transmitter diodes is approx. 1.2 m.
By simultaneously pressing the buttons "AF LEVEL" and "+" or "-" you can
adjust the AF level for the transmission channel you have just selected.
With the "+" button you increase the AF level.
With the "-" button you decrease the AF level.
The level is adjusted correctly when the modulation indicator occasio-
nally reaches the red part of the display (full modulation).
When both buttons are released, the selected AF level is stored.
This completes all settings for the first audio input channel. For adjusting the
next input channel, start again with CHOOSING THE AUDIO INPUT.
Channel display All transmission channels used are displayed: When a given input delivers
its signal to an IR transmission channel, the corresponding LED lights up.

14
Technical data
Modulation narrow-band FM
Channel frequencies 55 - 1,335 kHz
Channels: Channel 0 55 kHz Display: ºº Channel 16 735 kHz Display: ¡§
Channel 1 95 kHz Display: º¡ Channel 17 775 kHz Display: ¡¶
Channel 2 135 kHz Display: º™ Channel 18 815 kHz Display: ¡•
Channel 3 175 kHz Display: º£ Channel 19 855 kHz Display: ¡ª
Channel 4 215 kHz Display: º¢ Channel 20 895 kHz Display: ™º
Channel 5 255 kHz Display: ºS Channel 21 935 kHz Display: ™ ¡
Channel 6 295 kHz Display: º§ Channel 22 975 kHz Display: ™™
Channel 7 335 kHz Display: º¶ Channel 23 1015 kHz Display: ™£
Channel 8 375 kHz Display: º• Channel 24 1055 kHz Display: ™¢
Channel 9 415 kHz Display: ºª Channel 25 1095 kHz Display: ™S
Channel 10 495 kHz Display: ¡ º Channel 26 1135 kHz Display: ™§
Channel 11 535 kHz Display: ¡ ¡ Channel 27 1175 kHz Display: ™¶
Channel 12 575 kHz Display: ¡™ Channel 28 1215 kHz Display: ™•
Channel 13 615 kHz Display: ¡£ Channel 29 1255 kHz Display: ™ª
Channel 14 655 kHz Display: ¡¢ Channel 30 1295 kHz Display: £º
Channel 15 695 kHz Display: ¡S Channel 31 1335 kHz Display: £ ¡
Nominal/peak deviation ±6 kHz / ±7 kHz
Amplitude limitation limiting amplifier (max. 30 dB)
Deviation display via 12 LEDs: Peak, 5 dB, 3 dB, 1 dB, 0 dB, -1 dB,
-3 dB, -5 dB, -7 dB, -10 dB, -15 dB, -20 dB
AF inputs 5 transformer balanced XLR-3 inputs or a 25-pin SUB-D connector
AF input sensitivity 50 mV - 2.5 V (line) The modulator input can optionally be fitted with
microphone sensitivity (0.5 mV - 30 mV which can be done by your local
Sennheiser dealer. The modulator can also be equipped for a phantom
powered microphone.
AF frequency response 50 - 12,000 Hz
THD < 0.5 %
AF signal-to-noise ratio > 70 dB(A) eff.
RF output 2 x BNC (short-circuit proof), 0.6 V
2 x BNC (summing node, for connecting several radiators), 30 mV
Output impedance approx. 50 Ω
Suppression of harmonics > 60 dB
Power supply via plug-in mains unit, 12 V AC, 20 W
Power consumption max. 17 W
Dimensions 485 x 340 x 45 (1 U for installation in a 19" rack)
Weight approx. 4.0 kg
Subject to alterations

Sennheiser electronic GmbH & Co. KG
D-30900 Wedemark
Telefon: [phone]
Telefax: 05130/600-300
Printed in Germany
Publ. 6/97 54598 / A03