Kenwood TS-5700 Service Manual page 8

TS-570 0
•
I F Filter Rat i n g s (TX-RX U n it)
Item
N o m i n a l c e n t e r f re q u e n cy
Pass b a n d w i d t h
Atte n u a t i o n b a n d w i d t h
R i p p l e
I n se rt i o n l o s s
G u a ra nteed atte n u a t i o n
C e n t e r freq u e n cy d e v i a t i o n
Term i n a t i n g i m p e d a n c e
Item
N o m i n a l c e n t e r freq u e n cy
Pass b a n d w i d t h
Atte n u a t i o n b a n dw i d t h
R i p p l e
I n se rt i o n l o s s
G u a ra nteed atte n u a t i o n
Term i n a t i n g i m p e d a n c e
•
Receiver Fro nt- E n d
The signal input t o the TX-RX unit passes through
the attenuator switching circuit and the 30MHz low­
pass filter. The signal of less than 1.705MHz passes
through the low-pass filter and about-20dB attenuator
(the attenuator can be disabled by using a short
jumper). The signal of 1.705MHz or higher passes
through the short wave broadcast band trap (E type
only) and medium wave broadcast band trap and
passes through the nine-part band-pass filter. A PIN
diode for switching band-pass filters is used at the in­
put side to improve inter modulation.
8
CIRCUIT D ES CRIPTION
XF1 : L71-0401-05
73 0 5 M H z
± 7 . 5 k H z o r m o re at 3 d B
± 3 0 k H z o r l e s s at 4 0 d B
1 . 0 d B o r l e s s
3 O d B o r l e s s
7 0 d B o r m o re at f o + ( 5 00 - 1 O O O k H z )
7 0 d B o r m o re at fo - ( 2 00 - 1 O O O k H z )
With i n ± 1 . 5 k H z at 3 d B
2 kQ± 1 0 %
CF1 : L72-0372-05
4 5 5 k H z
± 6 k H z o r m o re at 6d B
± 1 3 k H z o r l e s s at 50d B
3d B o r l e s s (Wi t h i n 455± 4 k H z)
6 . 0 d B o r l e s s
3 5 d B o r m o re at f o ± 1 O O H z
2 kQ
RFA2
(21.5MHz­
PRE
O N :
Fi g. 6 Receiver front-end b l ock d i a g r a m
XF2: L71-0266-05
8830 k H z
± 3 . 0 k H z o r m o re at 6 d B
± 1 3 k H z o r l e s s at 50d B
± 1 6 k H z o r l e s s at 60d B
1 . 0 d B or l e s s
1 . 5 d B o r l e s s
7 0 d B o r more at f o ± 1 M H z
- 1 8 50Q I I 2 p F
CF500, 501 : L72-0351-05
8830 k H z
± 50 k H z o r m o r e at 3 d B
3 5 d B o r m o re at + 4 5 5 k H z
4 5 d B o r m o re at + 9 1 O k H z
1 . O d B o r l e s s
6 O d B o r l e s s
-
330Q
If PRE-AMP is off, 030 and 032 turn on, and the
signal passing through each band-pass filter goes to
the quad-balance type first mixer by 05 to 08:
2SK520x4. If PRE-AMP is on, 043 and 045 turn on,
and the signal of less than 21.5MHz passes through
parallel amplifier 017, 018: 2SK520x2. This amplifier
uses NFB to suppress the low-band gain and improve
strong signal input characteristics. When the fre­
quency is 22MHz or higher, 051 and 052 turn on, sen­
sitivity-oriented MOS FET amplifier 025: 3SK131 1s
selected.
L01
RFA1
(-21.5MHz
LI PRE LI
ON :
XF3: L71-0208-15
883 0 k H z
± 1 . 2 k H z o r more at 6 d B
± 1 . 5 k H z or l e s s at 2 0 d B
± 2 . 2 k H z or l e s s at 60d B
± 3 . 0 k H z or l e s s at SOd B
2 . 0d B o r l e s s
6 . 0 d B o r l e s s
80d B or m o re at fo± 1 M H z
600Q± 5 % I I 1 5 p F± 5 %
Wit h i n ± 1 5 0 H z at 6 d B
73.05MHz