Tyco Mastr III, Руководство по установке

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LBI-38636S
29
AUDIO ROUTING AND
ADJUSTMENTS
Once the T/R Shelf is installed and programmed
properly, audio level adjustments may be made for proper
system operation. Level adjustments must be made with a
handset (LBI-38599). THERE ARE NO MANUAL
MECHANICAL ADJUSTMENTS IN THE T/R SHELF.
Integrated circuits (IC's) U35 and U36 on the System
Board are dual electronic potentiometers that are
controlled by the microprocessor. IC U15 on the DSP
Board is also a dual electronic potentiometer controlled
by the DSP.
TX AUDIO LEVEL ADJUSTMENT
U36-0 is used to set the transmitter deviation by
adjusting the TX AUDIO output level. Analog switch
U15 selects, which audio source is routed to the
transmitter. Possible sources are LOCAL MIC, REPEAT
AUDIO, DSP LINE/TX AUDIO, DSP TX AUDIO,
EXTERNAL High Speed Data, LINE IN AUDIO, OPEN
(used for Morse code ID), and GROUND (used for no
transmission. A battery alarm tone may also be summed
in with whichever source is selected with the exception of
GROUND.
Normally, LOCAL MIC, REPEAT AUDIO, DSP TX
AUDIO, LINE IN AUDIO, OPEN, or GROUND will be
selected. The gains in the circuitry are set such that 100
mVrms in the MIC HI or 1 Vrms (3 kHz deviation) in on
VOL/SQ HI (REPEAT AUDIO) will produce the same
out-put level on TX AUDIO HI. The gains for Morse
code ID and battery alarm are also designed to provide the
proper levels without adjustments. The TX AUDIO HI
output level should be adjusted with a 100 mVrms, 1 kHz
signal in on MIC HI or a 1 Vrms, 1 kHz signal in on
VOL/SQ HI.