P
age
2
S
igtronicS
U
ltra
S
oUnd
US-lac4
and
US-lac6 i
ntercomS
www
.
SigtronicS
.
com
CONTROL FUNCTIONS
VOLUME — Intercom Volume: Adjusts intercom volume level. Does
not affect radio volume.
SQUELCH — Intercom Squelch: Adjusts VOX operation of the inter-
com for variations in background noise levels.
RADIO MIC TRANSMIT GAIN — Located on the back of the unit:
Sets the transmit mic audio level for the radio(s).
RADIO VOLUME — Located on the back of the unit: Sets the range
of receive audio from the radio(s).
ULTRASOUND INSTALLATION
Standard Equipment Included
Besides the Intercom unit, each UltraSound system comes complete
with the following:
US-LAC4 US-LAC6
Intercom Mounting Bracket .............................. 1 ................... 1
Headset Jack Box and Cover
with Pre-mounted Headset Jack ..................... 4 ................... 6
with Pre-mounted Headset Jack
& Splash Cover ........................................................ 1 ................... 1
PTT Switch Pre-mounted
in PTT Box and Cover ........................................... 6 ................... 6
Headset Hooks ....................................................... 4 ................... 6
Jack Box Cover Screws ........................................ 22 .................. 26
Jack Box and Bracket Mounting Screws ...... 34 .................. 42
Wire Grommets ..................................................... 11 .................. 13
Jack Insulator Washer, Flat ................................. 5 ................... 7
Jack Insulator Washer, Shoulder ...................... 5 ................... 7
4 ft. Headset Jack and PTT Switch Cable ...... 1 ................... 1
4 ft. Radio 1 Interface Cable .............................. 1 ................... 1
4 ft. Radio 2 Interface Cable .............................. 1 ................... 1
6 conductor hook-up wire (Roll) ...................... 1 ................... 1
4 ft. PTT Switch Cable ......................................... — ................... 1
Installation Overview:
Sigtronics has simplified the installation process, to assure perfect
operation. Refer to the UltraSound Wiring Diagram. For US-LAC4
see Figure 4; for US-LAC6 see Figure 5. If you have any installation
questions or problems that are not addressed in this manual, feel
free to call our installation hot line number located on the last page
of this manual.
Installation of the Sigtronics UltraSound System is a four step process:
I. Mount the intercom unit.
INTERCOM CHASSIS INSTALLATION
II. Install the headset jacks and PTT switches.
HEADSET JACK AND PTT SWITCH INSTALLATION
III. Wire the jacks and PTT switches.
HEADSET JACK AND PTT SWITCH WIRING
IV. Wire the radio(s).
RADIO HOOK UP
I. INTERCOM CHASSIS INSTALLATION
Intercom Placement:
There are a few factors to consider when selecting a mounting
location for the UltraSound Intercom chassis:
1. The unit should be placed in such a way that the controls on the
front of the unit can be easily seen and operated. Most commonly,
this will be near the vehicle’s communication radio controls.
2. The Intercom unit is primarily designed to be dash mounted. It
can be mounted on top of the dash or hang below the dash or
vehicle ceiling. The mounting bracket is adjustable to allow for
various mounting angles.
3. The location selected requires a minimum area of 2 5⁄16 inches high
by 7 7⁄8 inches wide by 4 inches deep. Verify that the intercom unit
and cables will not interfere with the normal operation of any
vehicle controls or the operation of vehicle compartment doors.
Mounting Intercom Unit: See Figures 1 and 8
1. Once the location is selected, remove the mounting bracket
from the intercom unit by unscrewing the two large knobs. Be
careful not to lose any of the four ratchet washers.
2. Set the mounting bracket in the selected area and mount with
four of the hex head self drilling screws. For most applications*
these screws can be installed with no pre drilling. Just power in
the screws with a standard electric driver with a 5⁄16 inch hex bit.
* No pre drilling required for aluminum and steel. A
1⁄8
inch pilot hole
will still be required with some stainless steels.
3. Place the intercom back into the bracket and replace the four
washers and two knobs. Set the Intercom to the desired angle
before tightening down the knobs.
II. HEADSET JACK AND PTT SWITCH INSTALLATION
Headset Jack Placement:
It is assumed that it has already been determined which positions
on the vehicle will have headsets. At this stage, it is helpful to have
a headset handy to physically gauge the best place for a particular
jack. There are several things to consider when selecting a place to
mount the headset jacks:
1. In general, for headset positions inside the vehicle, the jacks
should be placed towards the middle between the user’s posi-
tions. They should also be placed up above and towards the back
of the user’s head. This will assure that the headset cord will not
hang between the user and the vehicle door.
2. The headset jack should be out of the way so that the headset
plug can’t be hit during use or when entering or exiting the
vehicle.
3. The jack position should also take into account how the headset
cord will hang when the headset is in use. The cord should hang
out of the way and should not interfere with vehicle controls.
4. Verify that the jack placement and headset cable do not interfere
with the normal operation of vehicle doors or compartments.
5. In vehicles with intercom headset positions installed in open
jump seat locations, the combination of wind, road, and engine
