Sigtronics US-12D - Manual (Page 12)

voice clarity, the headset microphone must be positioned to
one side of the mouth and 1/4 inch from the lips. Turn the
volume control on the headset ear cup to maximum. Turn
down for individual hearing needs if necessary only after
intercom and radio volumes have been set correctly. (see
below)
Intercom operation and adjustment can be performed by
the following procedure:
1. Turn the intercom SQUELCH control to the maximum
clockwise position. For best system performance set the
intercom VOLUME control as low as possible. On most
systems this will be approximately the 10 o’clock posi-
tion. NOTE: the intercom volume control only adjusts the
volume of conversation between the headsets inside the
vehicle. It does not affect the level at which you hear the
dispatch radio. (see Radio Operation below) You should
now hear yourself and others on the intercom.
2. To adjust the Intercom SQUELCH for voice activated oper-
ation (VOX), it is helpful to have some background noise
(truck engine or ...). Turn intercom SQUELCH control all the
way counter-clockwise. Now, without speaking, rotate the
SQUELCH control clockwise until you hear the background
noise in your headset. Next, rotate it counter-clockwise in
small amounts until the background noise disappears.
Finally, make small adjustments until your voice triggers the
unit at comfortable speaking levels. This procedure is nec-
essary because the squelch is a “Fast-on, Slow-off” system.
When you speak, your voice will be heard in the headsets
but the sound will cut off about a second after you stop
speaking. Minor readjustment of the squelch may be nec-
essary if the background noise level changes significantly
(engine idling to cruise power with siren on).
Radio Operation
With the UltraSound System, your radio(s) are heard through
the headsets as well. Adjust the volume level of the dispatch
radio(s) in the headsets with the volume control on the radio
as normal. NOTE that the radio volume does not effect the
intercom volume and visa versa.
Transmitting (talking to dispatch) from the selected headset
positions is possible on a one-at-a-time basis. For a typical
UltraSound installation the Driver, Officer, or Crew #4 posi-
tions can transmit at any time simply by pressing their PTT
switch. The other positions cannot transmit on the radios.
When one position transmits, several things take place auto-
matically:
— All headset microphones, except for the transmitting
position, are muted.
— The selected radio is put into transmit mode.
— The headset microphone audio (your voice) is sent to
the selected radio.
— Sidetone is generated and sent to your headphones.*
* Sidetone is a portion of the transmitted voice signal sent
back into your headset so that you can hear what you are
saying while transmitting. The intercom VOLUME control
adjusts the volume level of the sidetone that you hear in
your headset. The other headsets will also hear the transmis-
Sigtronics Installation Hot Line Number:
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2-19-2013 US-12S_D Rev F
P/N700125
sion sidetone. Of course, when the PTT switch is released,
(stop transmitting) all functions return to normal, instantly
and automatically.
For Dual Radio Units - US-12D:
The operation of the dual radio UltraSound units are identi-
cal to that of the single radio units except for the addition of
radio selection:
Radio Selection of both Radio 1 and Radio 2 radios are pro-
vided by two switches.
1. RADIO 1/RADIO 2 (TALK) determines the radio you wish
to transmit on.
2. AUTO/BOTH (LISTEN) selects which radio(s) you receive
or hear in your headset.
a) “AUTO” position allows you to hear the radio that the
RADIO 1/RADIO 2 switch is set to.
b) “BOTH” position permits you to hear both the radios at
the same time.
igtronics
®
S
12
UltraSound Specifications
Input Voltage: 11 - 16 VDC
Nominal Current: 0.10 Amps
Maximum Current: 0.20 Amps
Intercom Unit Size: 1-3/4 “ H x 6 - 1/8” W x 4” D
(Mounting bracket & knobs add 9/16” to
H & 1 - 3/4” to W)
Weight: 15 oz. (not including cables and hard-
ware)
Warranty: Two Years