ASL INTERCOM PS 150 User Manual Download Page 5

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PAGE 5

User Manual PS 150 / May 2011 © ASL Intercom BV

8.0

ESTABLISHING A TELEPHONE CONNECTION

Proceed as follows:

1. Connect the telephone cable to the

TELEPHONE LINE connector (#11)

2. Connect a telephone set (phone) to the

PHONE connector (#12)

3. Make sure that the CONNECT button is not

pushed. The telephone line is switched to
the telephone set (phone). The HOLD Led is
not lit, indicating that the PS 150 is “off-line”

4. Take the telephone handset from the hook

(one hears a dial tone) and dial a phone
number

5. After a telephone connection has been

made, push the CONNECT button.
The telephone line is now switched to the
PS 150 and no longer to the phone.
The HOLD Led is lit, indicating that the PS
150 is “on-line”

6. Place the telephone handset back on the

hook of the telephone set (phone)

To terminate a telephone connection, push the
CONNECT button again. The HOLD Led now
extinguishes and the PS 150 is

“off-line”.

9.0

THE INTERFACES IN THE PS 150

The PS 150 contains two interfaces. One interface
splits the signal on the intercom party line into a
separate audio input and output. The other interface
splits the signal on the telephone line into a separate
audio input and output. The inputs and outputs are
internally cross connected.

Each interface has its own side tone trimming.
The trimmers

in the „intercom line‟ section of the

front panel control the input/output separation of the
intercom line interface. The trimmer in the
„telephone section‟ of the front panel controls the
input/output separation of the telephone line
interface.

To prevent internal feedback or a 'hollow sound' in
the intercom and the telephone system, all side tone
trimmers must be adjusted carefully.

Due to the complex impedance of the telephone
line, its input/output separation may be not as good
as the one of the intercom line. This may also
decrease the  side tone rejection in the intercom
stations on the intercom party line connected to the
PS 150.

If speaker stations are connected, feedback may
occur. To prevent this keep the SEND and
RECEIVE  levels of the PS 150 low and turn the
speaker attenuator trimmers of the howling speaker
stations counter-clockwise

10.0

ADJUSTING THE SIDE TONES

10.1

To adjust the side tone of the intercom party

line interface, proceed as follows:

1. plug a headset or headphones into the

TEST HEADSET connector (#10)

2.  set RECEIVE level to minimum
3.  set SEND level to maximum
4.  set intercom line side tone trimmers in start

position (LO trimmer: turn fully clockwise, HI
trimmer: turn fully counter-clockwise)

5. activate test tone generator by pushing

recessed button #4 with a pen or pin

6. decrease test tone listen level in the test

headset/headphone to a minimum by
turning the LO trimmer counter-clockwise.

7. decrease the listen level of the remaining

high frequencies to a minimum by turning
the HI trimmer clockwise.

8. repeat step 6 and 7 until you have obtained

the best possible settings (minimal levels).

Since the test tone is placed onto the intercom line
all connected intercom stations hear this tone. This
may be rather disturbing. It is advised to not adjust
this side tone whilst the intercom system is use.

10.2

To adjust the side tone of the telephone line

interface, proceed as follows:

1. Make sure that procedure 10.1 has been

executed

2. connect an ASL user station to the intercom

party line, connect a headset to that user
station and adjust the side tone of that
station to minimum level

3. Connect the PS 150 to the telephone line
4. Push the CONNECT button (#7). The PS

150 is now on-line. In the headset can(s)
you temporarily hear a dial tone

5. Set the side tone trimmer of the telephone

line interface (#9) in start position: fully
clockwise

6. set RECEIVE level to minimum
7. turn up RECEIVE level slowly while