TS-5700
28
CIRCUIT DESCRIPTION
3 ) Voice equalizing processi ng
A filter for voice equali zing processing is used to
change the transmission sound quality. It consists of
32-tap F I R filters. The characteristics of the filters are
shown below. To increase the voice equalizing effect,
the input signal is increased by 3dB and then filtered
when h igh boost, formant pass, or bass boost is set.
TX
0
Flat
OdB
1
H i boost ( H . B . )
2 . 2 k H z peak
2
Formant pass ( F . P . ) S u ppress 1 . 2 k H z to 1 . 6 k H z .
3
Bass boost ( B . B . )
2 0 0 H z peak
0
- - - -
...... :. - - -
co
!'.
Q)
- 1 0
'O
.�
a.
H . B .
- - - - - - T.C.
�
-20
----- 8.8.
-30
0. 1
Flat
- - - - F.P.
H i boost ( H . B . )
Formant pass ( F . P . )
Bass boost ( B . B . )
.
I
\
\
.J
0.4
0.7
Freq uency
( kHz )
Fig . 23
RX
OdB
2 . 2 k H z peak
S u p p ress 1 . 2 k H z to 1 . 6 k H z .
2 0 0 H z p e a k
4
Conventional (T. C . ) E m p h a s i ze 600 H z o r h i g h e r b y 3 d B .
Convention a l ( R . C . ) E m p h asize 1 k H z o r lower b y 2 d B .
4) Speech processor processing
Speech processor processing is carried out to im
prove the talk power in transmit mode. The band is
divided into th 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
input, and a low-pass filter, wh ich is a F IR filter, for
output. The IN-BPF HI output level is increased by
3dB 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- LPF MID
: 1 600Hz
OUT-LPF HI
: 3000Hz
5 ) VOX processin g
The TS-570D does not have t h e anti-VOX function
because the DSP correlates the receive tone signal
and the signal from the microphone and carries out
anti-VOX processing automatically. The signal from
the microphone is stored in the buffer in the DSP and
output with a delay t i me of 20ms to eliminate the
blank time at the beginning.
MIC
Delay
MIC
DELAY
Fig . 25
FILTER DATA
Comp. Level
Fig. 24
C 1 = 1
&
C2=1
VOXS
MIC
OUT
4
