8
innkeeper PBX™
VoIP/PBX Desktop Digital Hybird
A-B-C Selector Switch
Use this switch to select the correct type of handset microphone your telephone
uses.
A=Electret, B=Carbon, C=Dynamic
. Your innkeeper PBX will only
function correctly if the handset type selector switch is in the correct position.
This switch changes signal level, impedance, and wiring to accommodate the
differences in handset microphone types. To determine the correct position,
you should place a call to another telephone line, then try to send audio to the
phone line through the input jack of the innkeeper PBX . While doing this, switch
between the three different handset type positions. Choose the position that
works best by monitoring the audio quality and
<Send>
LEDs.
While speaking into the microphone, you should see the
<Send>
LEDs
lighting only. If the
<Caller>
LEDs also light up while you are speaking into the
microphone, you may have the
<A-B-C>
switch in the wrong position. If the
<Send>
LEDs light but the person at the other end of the call hears nothing at all,
or if you experience immediate feedback while levels seem to be set correctly,
you also may be in the wrong position.
Although not conclusive, the following guidelines may help:
• The majority of newer telephones have electret or dynamic type microphones
and will use the
<A>
or
<C>
position.
• Older telephones that have the round “screw type” handsets contain carbon
microphones and use the
<B>
position.
Optional Jumper Settings
There is a jumper located inside the innkeeper PBX at J9 that affects handset
operation. The factory default
closed
position (jumper covering both pins)
disables only the handset microphone when the
<Broadcast>
button is pressed.
Changing the jumper to the
open
position (either remove the jumper or cover
just one pin) allows you to completely disable both the handset microphone and
speaker when the
<Broadcast>
button is pressed.
If the incoming audio level from your telephone is too high and you are
consistently lighting the red –3dB Receive LED, first try decreasing the volume
using the handset volume controls on the base of your telephone. If you still
cannot drop the incoming audio level enough, and your unit was purchased after
February 2007, you may need to change jumper J10 inside innkeeper PBX.
There are three possible settings to adjust Caller receive level:
Pins 1 & 2 closed:
0dB (factory default)
Pins 2 & 3 closed:
-10dB
Pins 1-3 left open:
-20dB
To change the jumper settings, first disconnect power from the innkeeper PBX,
then remove the cover and locate the appropriate jumpers on the printed circuit
board.
Configuration
