User manual PS 6379 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
17
11.0 PARTY LINE, TECHNICAL CONCEPT
13.0 TECHNICAL SPECIFICATIONS PS 6379
ASL's PRO Series offers a complete two way ('full duplex')
communications system.
Users of the system are connected via a 'party line'.
Master stations (with built-in power supply), beltpacks,
speaker stations and power supplies are interconnected
via standard microphone cable. One wire is used as an
audio line, one as a power line and the screen of the cable
functions as earth/return.
Current drive is used for signal transfer. Each station
utilises a current amplifier to amplify the microphone signal
and place it on the common audio line where, due to the
constant line impedance (situated in the power supply
between XLR pin 3 and 1), a signal voltage is developed
which can be further amplified and sent to headphones or
loudspeakers.
This principle has three advantages:
- the use of a single audio line allows several stations to
talk and listen simultaneously.
- due to the high bridging impedance offered by each
station, the number of stations 'on line' has no influence
on the level of the communications signal.
- power and audio to the intercom stations use the
same cable.
The Call signal is also sent as a current on the audio line. It
develops a DC potential over the line impedance which will
be sensed by each station and interpreted as a Call signal.
12.0 WARRANTY
This unit is warranted by ASL Intercom against defects in
materials and workmanship for a period of two years from
date of purchase.
Faults arising from misuse, unauthorised modifications or
accidents are not covered by this warranty. If the unit is
faulty it should be sent in it's original packing, to the supplier
or your local ASL dealer, with shipping prepaid. A note must
be included stating the faults found and a copy of the
original suppliers invoice.
THIS PRODUCT WAS DESIGNED, DEVELOPED AND
MANUFACTURED BY:
ASL INTERCOM BV
UTRECHT, THE NETHERLANDS.
Website : http://www.asl-inter.com
POWER SUPPLY
Mains voltage
100 – 240 V AC 50/60 Hz (auto select)
DC output voltage
+30V +/- 2% DC
Max. output current
5A continuous / 7A peak
Circuit breaker delay time
0.2 sec
Automatic reset time
3.0 sec
MIC. PREAMP
gooseneck microphone type
noise cancelling electret
headset mic. impedance
200 ohms
gain
40 dB - 60 dB (adjustable internally)
presence filter
+6 dB at 5 kHz
frequency response
200 Hz - 15 kHz (-3 dB)
V electret mic
+9 V DC
Limiter range (gooseneck mic)
30 dB
HEADPHONES DRIVER AMP
max. load
100 ohms
max. output level
normal 17 V rms (200 ohms)
binaural 2 x 8.5V rms (400 ohms)
max. output power
normal 1 W rms (200 ohms)
binaural 2 x 0.2 W rms (400 ohms)
SPEAKER DRIVER AMP
speaker impedance
25 ohms
max. output power
2.9 W rms
PROGRAM INPUT
Input impedance
47 Kohms
Nominal input level
-12dbu to + 6 dBu
Max. input level
+ 16 dBu
AUX INPUT
Input impedance
11 Kohms
Gain
0 dB (line level)
Nominal input level
-20 dBu to + 10 dBu (line level)
Max. input level
+21 dBu (line level)
INTERCOM LINE DRIVER
max. output current
3 mA rms
output impedance
> 150 Kohms
SIDETONE
rejection
0 - 30dB adjustable
BUZZER
max. SPL
100 dBA
DIMENSIONS AND WEIGHT
Width / Height/ Depth
420 x 88 x 180 mm
weight
4,450 Kg
GENERAL SYSTEM SPECIFICATIONS
intercom line impedance 350 ohms (1kHz) 2.2Kohms (DC)
intercom line audio level
nom. -18 dBu max. +4 dBu
dynamic range
80 dB
call sent signal
+2.8 mA
call receive signal threshold
+2.4 V DC
supply voltage
+30 V DC (12 V to 32 V)
mic mute power interrupt time
0.1 sec
Note: 0 dBu = 775 mV into open circuit
ASL reserve the right to alter specifications without
further notice.
