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TS-570 0
3 ) Voice equalizing processi n g
A f i lter f o r voice equali z ing process ing is used to
change the transmission sound quality. It consists of
32-tap F I R filters. The characte ristics of the filters are
shown below. To increase the voice equalizing effect,
the input signal is increased by 3d B and then filtered
when h igh boost, formant pass, or bass boost is set.
0
F l a t
1
H i boost ( H . B . )
2
F o r m a n t p a s s ( F . P . )
3
B a s s boost ( B . B . )
4
C o n ve n t i o n a l (T. C . )
4) Speech processor p rocess i n g
Speech processor processing is carr ied out t o i m
prove t h e talk power in transmit mode. The band is
d i v i ded i nto t h ree parts to perform compression by
suppressing the harmonic distortion. A double-preci
sion band-pass filter, wh ich is a l l R filter, is used for
i nput, and a low-pass f i lter, wh ich is a F I R filter, for
output. The I N - B P F H I output level is i nc reased by
3d B to emphasize the h igh-frequency range.
IN-BPF LOW
: 200 or 500- 800Hz
IN-BPF M ID
: 800- 1 600Hz
IN-BPF HI
: 1 600-3000Hz
OUT-LPF LOW : 800Hz
OUT- LP F M ID
: 1 600Hz
OUT- LP F HI
: 3000Hz
5 ) VOX processi n g
The TS-570D does not have t h e anti-VOX function
because t h e DSP cor relates t h e recei ve tone s i gnal
and t h e si gnal f rom t h e microp hone and car r i es out
ant i-VOX processing automatically. T h e s ignal from
the microphone is stored in the buffer in the DSP and
output w i t h a delay t i me of 20ms to eli m i nate t h e
blank time a t the beginning.
28
CIRCUIT DESCRIPTION
TX
O d B
2 . 2 k H z p e a k
S u p press 1 . 2 k H z to 1 . 6 k H z .
2 0 0 H z p e a k
E m p h a s i ze 600 H z o r h i g h e r b y 3 d B .
Delay
MIC
- - - -
0
.ĕ
!'.
Q)
.�
- 1 0
'O
.Ĉ
�
H . B .
-20
- - - - - - T.C.
- - - - F.P.
-30
0. 1
F l a t
OdB
H i boost ( H . B . )
2 . 2 k H z peak
F o r m a n t p a s s ( F . P . )
S u p p ress 1 . 2 k H z to 1 . 6 k H z .
B a s s boost ( B . B . )
2 0 0 H z p e a k
C o n ve n t i o n a l ( R . C . )
E m p h a s i z e 1 k H z o r lower b y 2 d B .
FILTER DATA
&
C 1 = 1
DELAY
MIC
Fig . 25
.
I
\
\
.1
0.4
0.7
Freq u e n cy ( kHz )
Fig . 23
RX
C o m p . Level
Fig. 24
VOXS
C2= 1
OUT
MIC
4
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