Technisonic Industries Limited A711 L-Series, Руководство по установке

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ACCESS/A A711 L-Series Installation & Operating Instructions 09RE416
Technisonic Industries ltd. Copyright 1996, 1997, 2010, 2011 BY TiL ALL RIGHTS RESERVED Page 2-21
2.8
MICROPHONE INSTALLATION
All microphone connections to the A711L must be done with shielded cables. The inputs are
intended for use with standard “carbon-equivalent” or amplified dynamic Microphones (such as the
D/C M1, M4 M7, etc.). Shielded, twisted pair routing is strongly preferred for lowest noise pick-up,
but single conductor shielded wiring generally gives adequate results in non-critical or single box
installations, although noise floor and cross-talk will increase.
2.9
PTT CONNECTIONS
The Pilot, Co-pilot and hand microphones require a PTT (Push To Talk) button or switch to key the
transceivers as required. If a Hand-held microphone is used, tie the PTT button to the appropriate
key line. If a boom microphone is incorporated into the headset, an external switch, such as the
cyclic switch or yoke switch, will be required to key the transmitter. PTT lines should go directly to
ground to activate the desired key function.
2.10
MAIN POWER +28VDC
The main power +28VDC (±20%) is connected to Pin 17 of the 50 pin (lower) "D" connector, and
optionally to J102 Pin 6 as well, for annunciator control.
As previously indicated, this connection should be made with at least #22 AWG wire, with #20
preferred. If from a very noisy source, with high levels of parasitic AC, shielding may improve
rejection of this coupled AC into other low level audio lines.
2.11
BACKLIGHTING
POWER +28VDC
The backlighting power for the front panel of the A711L is supplied via pins 1 & 2 (and optionally
pin 3 for annunciator auto-dimming) of the 50 pin (lower) "D" connector. Unless ordered and
indicated otherwise on the rear of the ACCESS/A A711L, the unit is shipped with the +28VDC
normal lighting backlighting option. Note that there is a dedicated lighting ground pin, which
MUST be connected for the lighting to work. Lighting is isolated from other circuits in the system
for noise reduction reasons. Backlighting can be either normal (cool white) or NVG/ANVIS
compatible (green).