Sigtronics Dual-CFR - Manual (Page 7)

box. Use wire ties or tie wraps to secure and strain relieve
the wire.
At this time do not put the covers on the jack boxes or tighten
up the PTT switches. You will need to verify the correct opera-
tion of the system before you close everything up.
Power Connections:
The UltraSound unit will run on 11-16 VDC. CAUTION:
UltraSound units are designed for negative ground vehicles
only. They can be used on positive ground vehicles only if
a Sigtronics Positive Ground Adapter is used. Contact your
Sigtronics dealer on pricing and availability.
Make sure that the vehicle power is turned off before con-
necting the UltraSound power wire. The power for the
UltraSound unit comes in on the red and green wires on the
Headset Jack and PTT Switch Cable.
Connect the red wire to vehicle power. (Try not to use a power
buss that also runs electrical motors such as fans or light bars
with rotating lights.) Connect the green wire to the vehicle
chassis ground.
Intercom Wiring Check Out
System Setup:
Before you connect the vehicle’s radios, check out the system
operation. Do the following without the vehicle’s engine run-
ning:
First plug all headsets into the respective headset jacks. Put
on one of the headsets and position the boom mic close to
the mouth, as is the practice with hand-held microphones.
Voice clarity is best when the mic is about 1/4 inch away and
slightly off center from the lips. Turn the volume control on
the headset, all the way up (clockwise).
On the UltraSound unit, set both the intercom VOLUME con-
trol and SQUELCH control to full clockwise position.
Now turn vehicle power on. Verify that you can now hear
yourself in your headset. Verify also that you can hear all the
other headsets and that they can hear you. If everything is
OK, skip to the “PTT Test” on page 7. Otherwise, if something
is not working right, see the following troubleshooting guide
to find and fix the problem before going on with the instal-
lation:
NO INTERCOM IN ANY OF THE HEADSETS:
1. Make sure the UltraSound VOLUME and SQUELCH con-
trols are set to full clockwise position.
2. Make sure the vehicle power is on.
3. Check the in-line fuse in the UltraSound Headset Jack and
PTT switch Cable.
4. Check the power connection – red wire.
5. Check the ground connection – green wire.
6. Check for a short or open on the headphone wire (Blue
wire on the Headset Jack and PTT Switch Cable). The problem
could be anywhere along the blue wire connection between
the headset jacks and the UltraSound unit.
INTERCOM IN SOME HEADSETS BUT NOT IN OTHERS:
1. Make sure that UltraSound controls are set as above.
2. Make sure that none of the PTT buttons are pressed.
3. Make sure that none of the PTT wires (white/red, white/
blue, white/green or orange if applicable) are shorted to
ground.
4. Check specific “bad” headset jack wiring for:
a) Microphone wire (jack ring terminal) open or shorted
to ground.
b) Headphone wire (jack tip wire) open or shorted to
ground.
c) Incorrect wiring - wires switched either at the jack or
at the point where the hookup wire connects to the
Headset Jack and PTT Switch Cable.
LOUD SQUEAL IN THE HEADSETS ALL THE TIME:
1. First make sure all headset plugs are plugged in all the way
and that no part of any headset jack is physically touching
any metal.
2. Check headset jack wiring at all jacks. For example, incor-
rect wiring such as reversing the jack tip and ring wires will
cause a squeal.
3. Check for open headset jack barrel connection (black wire).
The open could be anywhere along the black wire connec-
tion between the jack and the UltraSound unit.
4. Check for a microphone line (white/black, white/orange, or
tan wires) shorted to the headphone line (blue wire). The
short could be at one of the headset jacks or in the wiring
between the unit and a jack.
Note that for 2 and 3 above, it will only squeal if a headset
is actually plugged into the specific jack that is wired incor-
rectly.
PTT Test:
If all above is good, make sure all headsets are plugged into
their respective jacks. Put on the Driver’s headset and posi-
tion the microphone as usual. Press one of the Driver’s PTT
switches. While continuing to hold down the switch, talk into
the mic and verify that you can still hear yourself. Also, while
holding down the PTT switch, verify that none of the other
headset microphones are active. Release that PTT switch and
try the Driver’s other PTT switch.
Now put on the Officer’s headset, position the microphone,
and press one of the Officer’s PTT switches. Verify that only
the Officer’s headset microphone is active as his switch is held
down. Now check the Officer’s other PTT switch.
If the system has the optional jack and PTT’s wired up at the
vehicles pump panel, unplug the headset from the Drivers
position and plug it into the pump panels jack. Press and hold
down one of the pump panel PTT switches. Verify that only
the pump panel headset microphone is active. Release that
PTT switch and try the other pump panel switch.
If all works fine, skip down to “Electrical Noise Test” on this
7