AVCOMM Safety Products
Installation Instructions: SC500 EasyLink
Intercom
Page 3 of 4
INSTALLATION CHECKLIST
!
Prepare installation site
!
Complete harness and wiring
connections
!
Install optional accessories
!
Test intercom functions before
permanent mounting
!
Make adjustments if needed
!
Finish permanent installation
!
Re-test all intercom functions
!
Have installation signed off by a
licensed communication
technician
3.
Wiring connections
a.
Headset & Remote PTT Jack Boxes:
Route the wires carefully so that the connectors and wire insulation are not
damaged by sharp or rough surfaces. Be careful not to install the cables backwards and make sure the connector
gender on the cable is in the appropriate location for connectors on the intercom, headset, and PTT boxes. Be sure
to leave enough cable length behind the intercom so it can be mounted easily.
b.
Radio:
One radio can be connected to the intercom. Please refer to the ‘Mobile Radio Adaptors for Intercoms and
Car Harnesses’ chart or contact your local AVCOMM dealer for the radio interface cable for your installation.
4.
Connect power source and chassis ground
a.
Power:
The intercom is designed for 12V D.C. negative ground systems. Connect the red and black power wires
to a noise clean vehicle power source: the black wire directly to the negative terminal of the battery (recommended),
the red wire to the positive (Fig. 2a). A spare fuse (2 AMP fast blow) is included for emergency backup (Fig. 2a~e).
b.
GND wire connection:
Connect GND wire to vehicle chassis (Fig. 2a).
Final Checkout and Adjustment
1.
Pre-set intercom controls
:
Squelch
–
Full clockwise position
Volume –
OFF (full counter-clockwise position)
2.
Test Intercom
: Turn on the intercom by rotating the volume knob clockwise
(50% rotation). A green light will appear at PWR/XMT LED.
3.
Test headset function
: First test the driver’s headset station. The intercom
should be operating with the squelch in the
Open mic mode
, at fully
clockwise position. As you speak you should be able to hear your voice in
the headset as side tone. Repeat this procedure for co-driver, pump panel and
crew positions by plugging the headset into their respective jacks.
4.
Test squelch
: Connect the headset to the driver jack. Position the
microphone no more than 1/8” from lips at the corner of the mouth (this is
critical to the performance of the noise-canceling electret microphone). Turn
the squelch knob counter-clockwise until the microphone stops picking up
background noise, then speak into the microphone. This should break the
squelch and your voice then can be heard through the headset.
5.
Test radio connection
: Vehicle radio reception should be heard in all headsets regardless of the squelch setting. The
volume of radio reception should be adjusted at the radio. Starting with the driver headset, test the radio transmission by
pressing the PTT for the radio and perform a radio check. The green LED will turn to yellow when the PTT is pressed
and the radio is transmitting. Repeat this test for the co-driver and pump-panel headsets.
6.
Mount intercom
: After all connections have been checked, slide the intercom into position. Assemble and tighten the
thumbscrews (a) and Nylatron washers (b) as illustrated in Fig. 1
GENERAL SPECIFICATION TABLE
ELECTRICAL CONTROL/FEATURES
MECHANICAL
Intercom: Monaural
Headphone impedance: 150-1000
Ω
typical
Audio output power: 250 mW
Audio distortion: <10% @ 85 mW into 150
Ω
load
Mic input source impedance: 680 ohms
Mic input source voltage: 8 ~ 9.6 V typical
3 dB Mic frequency response: 300 Hz-3000 Hz
Voltage supply: 12 ~ 28V DC
Current consumption: 33 mA typical w/2 headsets
Max current consumption: < 90 mA
Radio connections: single
Voice activated (VOX)
Volume control
Squelch control
Power transmit LED with ‘stuck mic’ indicator
Co-driver priority PTT
Number of positions: 2 – 6 places
EasyLink™ installation
Extruded aluminum construction
Thermoplastic Elastomer gaskets
Pre-wired for optional crews jacks
Dimensions: 4.96” L x 2.69” W x 1.19” H
Weight: 8.7 oz.