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Ut-12S
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Ut-12d i
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same thing. Do not use the type of filter that installs on or near
the alternator. NOTE: This solution should not be considered a
permanent fix. Vehicle charging system problems of this type
will eventually cause other equipment failure as well as shorten
the life of the vehicle’s batteries.
2. The other type of noise is that generated by equipment that uses
the vehicle’s power. This type of noise is usually constant and does
not vary with engine rpm. It does, however, go away completely
if the offending equipment is shut off or disconnected. Electrical
motors in fans or light bars with rotating lights are two common
examples.
Several things can be done to rectify this type of electrical noise:
a) Find a better (less noisy) vehicle power source for the Ultra-
Sound unit. Move the UltraSound red wire to another power
buss. Try not to use a power buss that also runs electrical
motors such as fans or light bars with rotating lights.
b) Move the UltraSound ground connection (green wire) to
another ground point on the vehicle.
c) Install an electrical noise filter on the power line going to
the equipment causing the noise. Contact the company that
makes the offending equipment for a recommendation on
the type of filter to use.
If something does not work as described, go back over the wiring
and correct before going on. If all is well, you can tighten all headset
jacks and secure all jack box covers with the supplied hardware.
Also, tighten and secure all PTT switches. On the UltraSound unit,
turn down the intercom VOLUME control to approximately the 10
o’clock position.
IV. RADIO HOOK UP
The connection of the UltraSound unit to the vehicle’s radio(s)
should be done by someone familiar with the radio(s) such as your
radio installer. Refer to the UltraSound Wiring Diagram - Figure 4 for
UT-12S units or Figure 5 for UT-12D units. Only the radio functions
are shown for the radio end of the UltraSound Radio Interface Cable.
Because the connector(s) used by radio manufacturers varies widely,
you will have to consult the radio manual or manufacturer for the
connector(s) and pin assignments used. Sigtronics has extensive
radio interface experience and can assist with any question you
might have concerning this or any other aspect of the UltraSound
system. See our installation hot line number located on the last
page of this manual.
First plug J2 of the Radio 1 Interface Cable into P2 of the Intercom.
Then using the radio manuals and the UltraSound Wiring Diagram,
identify the correct signal wires or connector pins to attach the
respective UltraSound wires. For most radios, these connections
are at the back of the radio or radio control head. For some radios,
the only place to connect the MIC HI and LO and PTT HI and LO
wires is to the hand-held microphone connector.* It is best to wire
in such a way that the radio hand microphone can still be used as
normal. Make sure that you do not physically tie the UltraSound
MIC LO and SPEAKER LO wires to the same pin on the radio, even
if they are tied together inside the radio. As in the headset wiring,
the connections between the UltraSound and radios should be
soldered and insulated for reliability. Do not use crimp type splices.
Use a good quality electrical tape or heat shrink tubing to cover the
soldered connections.
* For the more popular radios of this type Sigtronics manufactures
plug in “Y” adapters to make these connections easy. Contact your
Sigtronics dealer for pricing and availability.
For dual radio units (UT-12D), hook up Radio 1 first and test before
moving on to Radio 2.
Connect the six wires from the Radio 1 Interface Cable to the appro-
priate connections on the vehicle’s radio. Once that is done you will
need to set the RADIO 1 VOLUME switch on the back of the Ultra-
Sound unit. See Figure 6. This switch and the vehicles radio volume
control set how loud you hear the vehicles radio in the headsets.
For most applications the default setting of “LO” (up for Radio 1) is
fine. If the vehicles radio volume has to be turned up too high to
hear it in the headsets, set this switch to the “HI” position (down for
Radio 1). Otherwise leave it in the “LO” position. The switch can be
set with a pen or small flat blade screwdriver.
The last step is to set the Radio 1 Microphone Transmit Gain. Micro-
phone Transmit Gain (labeled MIC XMIT GAIN) adjustment for the
radio (or both radios for UT-12D) is also provided on the back of the
UltraSound unit. The adjustment(s) sets the microphone audio level
going to the radio(s) during transmit. The Microphone Transmit Gain
adjustment(s) will need to be initially set to your particular radio(s).
The gain(s) once set, should never need adjustment again unless the
type of radio(s) used is changed. The following simple procedures
take you through the adjustment of the Microphone Transmit Gain(s).
Radio Microphone Transmit Gain Adjustment can be made with
a small, flat blade screwdriver. Referring to Figure 6 above, the gain
adjustment is set by two controls - a “HI/LO” RANGE switch and a
rotary “ADJ” control. Set the RADIO 1 MIC XMIT GAIN RANGE switch
to the “LO” position (up for Radio 1). This is the default factory set-
ting. Adjust the “ADJ” control clockwise to increase the output gain
or level to the radio. Counter-clockwise rotation decreases it. The
basic adjustment concept is simple. You will be setting the level and
clarity of outgoing radio transmissions through the UltraSound unit
headsets, to match or exceed that of transmissions using the radio’s
standard hand microphone. To do this, you will need to transmit
and receive on the vehicle’s radio to a remote station. Arrange to
have someone nearby with a radio compatible to the radio you are
using with the UltraSound. Then…
RADIO VOLUME switch for Radio 2*
MIC XMIT GAIN RANGE switch for Radio 2
*
MIC XMIT GAIN ADJ for Radio 2
*
MIC XMIT GAIN ADJ for Radio 1
MIC XMIT GAIN RANGE switch for Radio 1
RADIO VOLUME switch for Radio 1
RADIO
VOLUME LO
HI
RADIO 2
RADIO 1
HI
LO
MIC
XMIT
RANGE
MIC XMIT
GAIN ADJ
*
*
On Dual Radio units only. Model UT-12D.
FIGURE 6