C-2000 and C-2000HS Technical Manual
Installation 15
Bosch Security Systems, Inc.
Technical Manual
F.01U.174.927 Rev 03
Mic Input level Adjustment
CAUTION:
Care should be taken to avoid over-driving the input TX circuitry, as this distorts the audio. Verify you enable the
desired microphone connection in setup mode. Saying and holding the word
four
is a good audio level test
vocalization. Use a strong tone of voice.
To
adjust the handset audio input level
, do the following:
1.
Connect an
oscilloscope
to test point TP3.
2.
Adjust
R115.
3.
Speak into the
handset.
4.
Adjust the
audio
to approximately 3.5Vp-p.
A portion of the handset audio will be routed to the handset earpiece, this level is adjustable in setup mode. For the
Desk Microphone input, repeat the sequence only monitor test point TP2 and adjust R105. Make sure that the Desk
Microphone is at the normal distance from the operator when setting the level.
TX Output Level Adjust
The transmit level potentiometer is used to adjust the
Output Level
of the transmit audio so it is calibrated with the tone levels
set in setup mode. Calibration of the TX line varies depending on system variables as well as the number of consoles found in
parallel on the line. An easy way to align the console for the correct level is to press and hold the PTT key. While the console
is keyed up, the unit by default, generates a Hold tone at –20dBm. A meter reading dBm is used and R171 adjusted to read the
correct value. Also an alignment tone state 50 is provided (REV.2.3 and higher operating software).
Transmit Monitor Setup
The
Transmit Monitor
provides a portion of the transmit audio of a 4-wire circuit to the receive path. This allows the console
operator to listen to the transmissions of parallel console operators.
To
set this level have a parallel console operator,
do the following:
1.
Press the
intercom
button.
2.
Adjust
R104
until the level is comfortable in the handset/headset earpiece or the speaker.
NOTE:
Make sure this feature is enabled or no audio will be passed. See “Setup Mode” on page 17.
RX Level Adjustment
The
RX Level
should be adjusted so the maximum level coming into the console use the entire range of the
ADC
(Analog to Digital Converter), which is 0–4V. A test tone of +3dBm to -5dBm coming into the line interface is a good
value to use. Adjust R89 so the signal seen on an oscilloscope at test point TP4 is approximately 3.8Vp-p.
