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CIRCUIT DESCRIPTION
RX Section (X55-1270-10)
The RF s ~ g n a l a m p l ~ f i e d by the front end dual gate M O S FET
Q1
IS
a p p l ~ e d through the
helical
resonator L3 to Q 2 to
obtain a 1 0 . 6 9 5 M H z IF s~gnal
The output of Q 2 passes through the 2-element MCF ( m o n o -
l ~ t h l c crystal filter to p r o v ~ d e an excellent 2-signal cha-
racterlstlc. The IF signal amplif~ed by Q 3
I S
a p p l ~ e d to Q 6 t o
produce the 4 5 5 kHz 2nd IF s~gnal. T h ~ s s ~ g n a l
IS
then
a m p l l f ~ e d by 0 7 - 1 1 and
IS
a p p l ~ e d to the ceramic discriml-
nator L13. The output from 0 8 ( 4 5 5 kHz ampllfler)
I S
fed t o
the LED level meter for an S meter slgnal
The squelch clrcult. composed of (312-1 5, controls the AF
clrcult (218. The busy lamp drlve s~gnal and scan busy stop
s~gnal (SS) are produced by Q 1 6 and 17 and fed t o the busy
Table
3
Ceramic filter (L72-0014-05) SFE10.7MA5
lamp circult on the d~splay unlt and the scan c ~ r c u i t o n the
(RX unit: L7)
control unlt.
The AF slgnal
I S
a m p l l f ~ e d by Q18. This
I S
fed t o the power
ampllfler Q 2 0 through the active LPF (low pass f ~ l t e r ) Q 1 9
and the AF galn control.
Hum ratio
Voltage allowance
wlth a shorted load
Table 1. HA1366W (RX Unit: Q20)
HR
3
52.8
-
55.0
Rank
Gv (dB)
Table 2. MCF (L71-0216-05)
(RX Unit : XF1)
l tern
Nomlnal center frequency(f0)
Pass bandw~dth
Attenuatlon bandw~dth
Guaranteed
attenuation
Rlpple
Loss
Impedance
f = 5 0 0 H z
f
=
500 Hz
Vin
=
1 0 mV.
t
=
5 sec.
1
50.0
-
52.2
Ratrng
1 0 695 MHz
f 7 5 kHz or more at 3 dB
+ 2 5 kHz or less at 4 0 dB
+ 4 5 kHz or less at 6 0 dB
1 7OdB or more wlthln f
1
MHz
2 Spurlous level = 4 0 dB or more
at fo
-
fo
j-
5 0 0 kHz
3 Spurlous level
=
8 0 dB or more
a t f o
-
( 9 1 0 HZ
f
1 0 ~ H Z )
1
0
dB or less
1 5 dB or less
3 M/O
pF
Item
Nominal center frequency
3 dB bandwidth
2 0 dB bandw~dth
Ripple
Loss
Spurious response
lnput and output impedance
2
5 1 . 4
-
53.6
Table 4. Ceramic filter (L72-0315-05) CFW455F
(RX Unit: L10)
Rating
A: 10.7 MHz (RED)
B: 10.67 MHz(BLUE)
C: 10.73 MHz (ORANGE)
I
t 3 0 kHz
D:
10.64 MHz (BLACK)
E: 10.76 MHz (WHITE)
2 8 0 f 5 0 kHz
6 5 0 kHz or less
0.5 dB or less
6 dB or less
3 0 d B o r m o r e a t 9
-
1 2 M H z
330R
Item
Nominal center frequency
6 dB bandwidth
5 0 dB bandwidth
Ripple (within 455
f
4 kHz)
Loss
Guaranteed attenuation
(within 4 5 5 f 100 kHz)
Input and output impedance
28.0
16.0
TX Section (X55-1270-10, X45-1150-10)
The microphone and Touch Tone signals are arnpl~fled by
Q 2 9 and fed to the F M modulator vari-cap d ~ o d e D 2 0
through the MIC amplif~er Q 3 0 and splatter filter to produce
an F M slgnal
The 1 0 6 9 5 M H z s ~ g n a l from the osc~llator
clrcult Q31
IS
a p p l ~ e d to the transmlt balanced mlxer ((333.
Q 3 4 ) vla buffer amplrfier 0 3 2 The 1 4 4 MHz slgnal obtarned
from the balanced mixer
IS
fed through the 4-stage BPF ( w ~ t h
voltage var~able tuning) to e l ~ m i n a t e unwanted spurlous
components
Thls s~gnal is then a r n p l ~ f ~ e d by Q 3 5 and 3 6 to drive the flnal
unlt
Both 0 3 6 and the Final unlt are powered by the DB
L ~ n e whlch also functrons at l o w power and during
protectlon
The D B clrcult
IS
a 1 2 4V AVR (Automatic
Voltage Regulator) circult uslng (22-5 and D 5
The s ~ g n a l to the F ~ n a l unlt
IS
power arnpllf~ed by the power
h y b r ~ d Q 6
Ir passes through the transm~t/rece~ve antenna
s w ~ t c h d ~ o d e s D l . D2.
harmonics
are ellm~nated by LPF
( L o w Pass
Filter),
and the s ~ g n a l
IS
then a p p l ~ e d to the ANT
terminal
The protectlon clrcult
IS
an
automatic
reset VSWR detector
DB voltage
I S
dropped by drlvlng Q 1 w ~ t h the reflected output
component
Low power control
IS
effected by RL1, which
switches the power h y b r ~ d FB terminal over to the DB line
Power
I S
reduced t o 5 W by controll~ng the D B llne with VR4
Rating
4 5 5 kHz+ 1 kHz
+6
kHz or more
f
12.5 kHz or less
3 dB or less
6 dB or less
3 5 dB or more
2.0 kQ
-
-
-
-
J
d 8
v
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