Kenwood TR-2600A - Page 2

TR-2600A/E
CIRCUIT
DESCRIPTION
@ DESTINATION
TR-2600A : K,M1,M2,M3, X
TR-2600E :T,W
@ DESTINATION ABBREVIATION
K UGA, M1, M3 : General
-M2 : Latin America, Canada
T : England W : Europe
X : Australia
RECEIVER RX UNIT (X55-1380-XX)
The
RX
unit
basic
configuration
employs
a
double
conver-
sion
superheterodyne
reception
system
in
which
the
first
iF
is
10.7MHz
and
the
second
IF
is
455kHz.
@ Signal system
A
received
signal
supplied
through
the
Low
Pass
Filter
cir-
cuit
from
the
TX
unit
is
amplified
by
RF
amplifiers
Q1
:
2SC2671(H)
and
Q2
:
2SC2668(Y).
It
is
then
converted
by
the
first
mixer
O3
:
2SK192A(Y)
to
the
first
IF
at
10.7MHz.
The
VCO
injection
signal
is
supplied
from
the
TX
unit.
The
RF
amplifiers
are
tuned
in
two
bands,
controlled
by
the
BSW
signal
from
the
TX
unit:
the
low
frequency
band
is
140
to
150MHz
and
the
high
frequency
band
is
150
to
160MHz.
The
converter
output
is
filtered
through
MCF
F1
at
10.7MHz,
and
is
then
1st
IF
amplified
by
Q4
and
Qs
:
2SC2668(Y)
before
being
fed
to
Q6
:
MC3357P,
where
the
signal
is
converted
to
465kHz
by
oscillator
X1
(10.245MHz),
passed
through
the
455kHz
ceramic
filter
F2,
amplified,
limited,
and
finally
detected.
Q6
also
con-
tains
the
squelch
circuit.
Part
of
the
signal
sampled
from
F2
is
fed
to
the
S
meter
amplifiers
Q11
and
Q12:
2SC2603(E).
@
DESTINATION
CODE
FOR
REFERING
PARTS
LIST
General TR-2600A/E
010
021
022
023
051
K
M1
M2
M3
T
W
x
RX
unit
X55-138X-XX
010
021
022
061
071
K
M3
M1
Tw
[M2-X
TX
unit
X56-147X-XX
010
051
061
K-M1-M2-M3-X
als
W
DCL unit X57-111X-XX
010
K-M1-M2-M3-7-W-X
The
S$
meter
circuit
is
energited
and
operates
only
when
the
squelch
circuit
is
open
via
voltage
switch
Q10:
DTC143TS.
The
detected
signal,
after
passing
through
the
AF
gain
con-
trol,
is
power
amplified
by
Q8
:
BA526
and
is
fed
to
the
speaker.
Q7
:
2SC2603(E)
cuts
the
audio
signal
by
means
of
the
AFC
signal
from
the
Control
unit.
Q9
:
DTC124ES
provides
‘‘Beep’’
tone
injection
to
the
speaker
while
Q8
is
off.
Rating
10.7MHz
Pass
bandwidth
+7.5kHz
or
more
at
3dB
+25kHz or less at 40dB
+45kHz or less at 60dB
70dB
or
more
within
1MHz
Spurious
level
=
40dB
or
more
Nominal center frequency
Attenuation bandwidth
Guaranteed
attenuation
at
foxto-*e00kHe,
80dB
or
more
at
fo—(Q00—920kHz)
Ripple
1.0dB
or
less
Loss 1.5dB or less
3k2/O0p F
Input and output impedance
Table
1
MCF
(L71-0228-05)
(RX
unit
F1)