TS-590S
9
The BPF divides in the range as shown in table 3. The
BC band’s BPF includes ATT for avoiding cross-modula-
tion by medium wave band high-output station (ATT ON:
CN102=open, CN103=short, ATT OFF: CN102=short,
CN103=open). The transmit signal also passes through the
BPF when transmitting.
The preamplifier (Q236) receives the signal passed
through the BPF. In this model, it is an emitter grounding
circuit which uses a bipolar transistor. Q239 switches the
emitter’s returning amount to adjust the gain. Approximately
20dB is gained in 21.5 to 60MHz and approximately 12dB in
other frequencies. The preamplifi er circuit can be passed by
turning off the PRE display with the preamplifi er key.
ANT1
ANT2
AT
TX
signal
RX
TX
ATT
ATT
–12dB
(–20dB)
ATT
ATT
PRE OFF
to 1st Mixer
BC TRAP
(EU TRAP)
BPF
1.705~60MHz
x11
BPF
LPF
522kHz~
1.705MHz
LPF
30kHz~
522kHz
LPF
~60MHz
Q236
PRE AMP
RX ANT
X57-785 (A/2)
X45-391 (A/2)
Band
Filter range
135kHz
30~522kHz
BC
522kHz~1.705MHz
1.8MHz
1.705~2.5MHz
3.5MHz
2.5~4.1MHz
5MHz
4.1~6.9MHz
7MHz
6.9~7.5MHz
10MHz
7.5~10.5MHz
10.5~13.9MHz
14MHz
13.9~14.5MHz
14.5~21.5MHz
18MHz
21MHz
28MHz
21.5~30.0MHz
50MHz (TX)
49.0~54.0MHz
50MHz (RX)
30.0~60.0MHz
Table 3 BPF range
Fig. 3 From antenna terminal to preamplifi er (Q236)
CIRCUIT DESCRIPTION
Содержание TS-590S
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