Sigtronics S-A-F-E Operating Instructions - Manual (Page 2)

Radio Selection of both the A/C (Radio 1) and FM
(Radio 2) radios are provided by two switches.
1. XMIT SELECT determines the radio you wish to
transmit on.
2. BOTH/OFF/AUTO selects which radio(s) you
receive or hear in your headset.
a) “BOTH” position permits you to hear both the
radios at the same time.
b) “OFF” position disables the hearing of either
radio.
c) “AUTO” position allows you to hear the radio
that the XMIT SELECT switch is set to.
The AUXiliary audio source is selected by the AUX/OFF
switch. In the “AUX” position, you can hear it, and in
the “OFF” position you cannot.
Receive Volume Controls (REC VOL) are general
volume controls, meant to provide overall listening
level for all three radios simultaneously - A/C radio, FM
radio, and AUXiliary radio. Finite volume adjustments
of any individual radio should be done by altering the
radio volume control at the radio itself.
Once the radios are selected, Officer 1 (right side) or
Officer 2 (left side) can transmit at any time simply
by pressing their PTT switch. The two Crew positions
cannot transmit on the radios. When one position
transmits, several things take place automatically to
the transmitting side of the SAFE unit:
• The intercom between the two sides of the SAFE unit
is turned off.
• The Auxiliary audio, if selected, is muted.
• The receive audio of the radio not selected by the
XMIT SELECT switch is muted, regardless of the posi-
tion of the BOTH/OFF/AUTO switch.
• If Officer 1 is transmitting, both Crew headset micro-
phones 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 head-
phones.*
* 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 RECeive
VOLume control adjusts the volume level of the
sidetone that you hear in your headset.
The non-transmitting side of the SAFE is not affected
(except for intercom) when the other side transmits.
The non-transmitting side can monitor the transmis-
sions of the other side by simply selecting the same
radio on his side of the SAFE. Of course, when the PTT
switch is released, (stop transmitting) all functions
return to normal, instantly and automatically.
Simultaneous Transmit is the most attractive and
powerful feature of the SAFE. Both Officers 1 and 2
can transmit at the same time – either on separate
radios or on the same radio transmitter! When on
different radios, neither Officer position will interfere
with the other’s communications. For example, if using
the SAFE on an airport crash vehicle, Officer 2 can talk
to air traffic control while Officer 1 talks on the emer-
gency dispatch radio, or visa versa. On the other hand,
they can also transmit on the same radio transmitter.
If, for example, Officer 1 is talking on one of the radios,
Officer 2 can jump right in and add to the conversation
simply by pressing his PTT switch. Both voices will be
heard by the receiving station.
NOTE: Only the A/C radio and the FM radio can be
transmitted on. The AUXiliary input is for listening
only. It can be used for listening to a scanner, moni-
toring the audio portion of a video camera, listening
to background music, and many other possibilities.
1-8-2007 safeoper.pdf