ASL INTERCOM PS 6379 Mk2 User Manual page 10

21 SPEAKER ATTENUATOR trimmer
To adjust the extent to which the loudspeaker is
automatically dimmed when the gooseneck
microphone is switched on. It prevents unit
feedback if Null Adjust is not sufficient. It also
minimizes system feedback or a 'hollow' sound
when the gooseneck microphones of other
speaker stations (on one or several of the
connected party lines) are switched on as well.
Adjustment procedure :
• make sure that there is no headset
connected
• switch off all TALK buttons of the PS 6379
Mk2.
• feed an audio signal to an intercom channel
(see #9 and #34)
• turn up the listen volume of the PS 6379
Mk2 (selected channel and master
volume)
• activate the gooseneck microphone (push
the TALK button of the selected channel)
• adjust the desired degree of speaker
attenuation (turning the trimmer counter-
clockwise increases the attenuation)
22 BUZZER VOLUME trimmer
To adjust the volume of the internal buzzer.
23 IFB DIM FACTOR trimmers
By turning these trimmers, the IFB DIM factor for
channel E and channel F can be set, should these
channels being put into IFB Mode (see switches
#36). The IFB Dim Factor is the extent to which
the AUX signal is dimmed (0% to 100%) when
pushing the TALK button of a channel which is put
into IFB mode. If the knob is fully clockwise, the
DIM factor is at its maximum (100% dimming)
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User Manual PS 6379 Mk2 / October 2013 © ASL Intercom BV
24 BACKLIGHT trimmer
If TALK or CALL push buttons are not active, they
are lit white allowing to easily find these buttons in
a dark environment. By turning this trimmer the
light intensity can be adjusted.
25 Master OVERLOAD LED indicator
As soon as more than the allowed maximum
allowed user stations are connected to the PS
6379 Mk2 (the current from the built-in PSU is in
danger to exceed 5A) the red Overload LED is lit
and a circuit breaker disconnects the line power
from all channels. The circuit-breaker resets
(restores line power) automatically 3 seconds after
the cause of the overload has been removed. The
LED also lights up red - for a few seconds - every
time mains power is switched on.
26 MAINS LED indicator
If mains power is switched on (see #31 'Mains
Power On/Off switch') this green LED is lit.
27 DC power LED indicator
If the DC input on the rear panel (see #41)
receives DC power (24 – 30V / 5A) this yellow
LED is lit.
28 HEADSET connector
To this XLR-4 connector of a headset can be
connected. The headset must have a can
impedance of minimum 200 ohms. If the headset
has two cans in parallel, each can must have an
impedance of minimum 400 ohms.
The headset microphone may be of the dynamic
or electret type. .A limiter prevents the mic pre-
amp from clipping when speaking close or loud
into the headset microphone.The gain for the
headset mic can be adjusted by trimmer #45.