TS-570 0
2
CI R CU IT D ES CR I PTION
Frequency Config u ration
The TS-570D utilizes double conversion in all trans
mit modes and non-FM receive modes, and triple con
version in FM mode.
When the receiver frequency flN from the antenna
in SSB mode is zero beat (i.e., at zero to the SSB signal
with a carrier point of flN), the relationship between
these signals is expressed as follows:
flN
=
fL01 - fL02 - f
CA
R
All the frequencies are generated by the PLL circuit
as shown in the PLL block diagram in Figure 2, and the
receiver frequency is determined by the reference fre
quency fSTD, the PLL divide ratio and DDS data. There
fore, the reference frequency accuracy equals the op
erating frequency accuracy.
The accuracy of the reference crystal oscillator in
the TS-570D is 10 ppm (-10 to +50°C). If an optional
temperature compensated crystal oscillator (TCXO)
S0-2 is installed, the accuracy becomes 0.5 ppm (-10
to +50°C).
ANT
flN
TX MIX 2
73.05MHz
TX MIX
1
When the transmitter is used in SSB mode or in
other modes, likewise, the frequency is determined by
the reference frequency fSTD and PLL divide ratio. The
display frequencies in the modes are listed in Table 1.
In FSK mode, the TS-570D displays the mark trans
mitter frequency.
In CW mode, the TS-570D uses the variable CW
pitch system so that the receiving pitch can be
changed in the range 400 to 1 OOOHz in 50Hz steps
while the desired signal remains in the center of the IF
filter band. Since the receiving pitch varies with the
side tone, it is possible to zero in by receiving the de
sired signal at the same pitch as the side tone.
FM transmission is carried out by sending the audio
signal from the microphone to the 64.22MHz VCO and
modulating fl02.
Mode
Display frequency
USB,LSB
Carrier point freq u e n cy
cw
Tra n s m ission carrier freq u e n cy
F S K
M a rk tra n s m itter freq u e n cy
A M , F M
I F filter center freq u e n cy
Table
1
Display frequ ency i n each mode
B.M
MIC INPUT
DSP
AF OUTPUT
FM
FM TX: ON
Fig.
1
Frequency configuration
